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Wu M, Xu Y, Zhao C, Huang H, Liu C, Duan X, Zhang X, Zhao G, Chen Y. Efficient nitrate and Cr(VI) removal by denitrifier: The mechanism of S. oneidensis MR-1 promoting electron production, transportation and consumption. J Hazard Mater 2024; 469:133675. [PMID: 38508109 DOI: 10.1016/j.jhazmat.2024.133675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/21/2024] [Accepted: 01/29/2024] [Indexed: 03/22/2024]
Abstract
When Cr(VI) and nitrate coexist, the efficiency of both bio-denitrification and Cr(VI) bio-reduction is poor because chromate hinders bacterial normal functions (i.e., electron production, transportation and consumption). Moreover, under anaerobic condition, the method about efficient nitrate and Cr(VI) removal remained unclear. In this paper, the addition of Shewanella oneidensis MR-1 to promote the electron production, transportation and consumption of denitrifier and cause an increase in the removal of nitrate and Cr(VI). The efficiency of nitrate and Cr(VI) removal accomplished by P. denitrificans as a used model denitrifier increased respectively from 51.3% to 96.1% and 34.3% to 99.8% after S. oneidensis MR-1 addition. The mechanism investigations revealed that P. denitrificans provided S. oneidensis MR-1 with lactate, which was utilized to secreted riboflavin and phenazine by S. oneidensis MR-1. The riboflavin served as coenzymes of cellular reductants (i.e., thioredoxin and glutathione) in P. denitrificans, which created favorable intracellular microenvironment conditions for electron generation. Meanwhile, phenazine promoted biofilm formation, which increased the adsorption of Cr(VI) on the cell surface and accelerated the Cr(VI) reduction by membrane bound chromate reductases thereby reducing damage to other enzymes respectively. Overall, this strategy reduced the negative effect of chromate, thus improved the generation, transportation, and consumption of electrons. SYNOPSIS: The presence of S. oneidensis MR-1 facilitated nitrate and Cr(VI) removal by P. denitrificans through decreasing the negative effect of chromate due to the metabolites' secretion.
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Affiliation(s)
- Meirou Wu
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yanan Xu
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Chunxia Zhao
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Haining Huang
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Chao Liu
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xu Duan
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xuemeng Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Guohua Zhao
- School of Chemical Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yinguang Chen
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
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Horst F, Bodenstein E, Brand M, Hans S, Karsch L, Lessmann E, Löck S, Schürer M, Pawelke J, Beyreuther E. Dose and dose rate dependence of the tissue sparing effect at ultra-high dose rate studied for proton and electron beams using the zebrafish embryo model. Radiother Oncol 2024; 194:110197. [PMID: 38447870 DOI: 10.1016/j.radonc.2024.110197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/16/2024] [Accepted: 02/26/2024] [Indexed: 03/08/2024]
Abstract
PURPOSE A better characterization of the dependence of the tissue sparing effect at ultra-high dose rate (UHDR) on physical beam parameters (dose, dose rate, radiation quality) would be helpful towards a mechanistic understanding of the FLASH effect and for its broader clinical translation. To address this, a comprehensive study on the normal tissue sparing at UHDR using the zebrafish embryo (ZFE) model was conducted. METHODS One-day-old ZFE were irradiated over a wide dose range (15-95 Gy) in three different beams (proton entrance channel, proton spread out Bragg peak and 30 MeV electrons) at UHDR and reference dose rate. After irradiation the ZFE were incubated for 4 days and then analyzed for four different biological endpoints (pericardial edema, curved spine, embryo length and eye diameter). RESULTS Dose-effect curves were obtained and a sparing effect at UHDR was observed for all three beams. It was demonstrated that proton relative biological effectiveness and UHDR sparing are both relevant to predict the resulting dose response. Dose dependent FLASH modifying factors (FMF) for ZFE were found to be compatible with rodent data from the literature. It was found that the UHDR sparing effect saturates at doses above ∼ 50 Gy with an FMF of ∼ 0.7-0.8. A strong dose rate dependence of the tissue sparing effect in ZFE was observed. The magnitude of the maximum sparing effect was comparable for all studied biological endpoints. CONCLUSION The ZFE model was shown to be a suitable pre-clinical high-throughput model for radiobiological studies on FLASH radiotherapy, providing results comparable to rodent models. This underlines the relevance of ZFE studies for FLASH radiotherapy research.
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Affiliation(s)
- Felix Horst
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Elisabeth Bodenstein
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Michael Brand
- Center for Regenerative Therapies TU Dresden and Cluster of Excellence 'Physics of Life', Technische Universität Dresden, Dresden, Germany
| | - Stefan Hans
- Center for Regenerative Therapies TU Dresden and Cluster of Excellence 'Physics of Life', Technische Universität Dresden, Dresden, Germany
| | - Leonhard Karsch
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Elisabeth Lessmann
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Steffen Löck
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Schürer
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; National Center for Tumor Diseases Dresden (NCT/UCC), Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
| | - Jörg Pawelke
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Elke Beyreuther
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany.
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Ye W, Yan J, Yan J, Lin JG, Ji Q, Li Z, Ganjidoust H, Huang L, Li M, Zhang H. Potential electron acceptors for ammonium oxidation in wastewater treatment system under anoxic condition: a review. Environ Res 2024:118984. [PMID: 38670211 DOI: 10.1016/j.envres.2024.118984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/16/2024] [Accepted: 04/21/2024] [Indexed: 04/28/2024]
Abstract
Anaerobic ammonium oxidation has been considered as an environmental-friendly and energy-efficient biological nitrogen removal (BNR) technology. Recently, new reaction pathway for ammonium oxidation under anaerobic condition had been discovered. In addition to nitrite, iron trivalent, sulfate, manganese and electrons from electrode might be potential electron acceptors for ammonium oxidation, which can be coupled to traditional BNR process for wastewater treatment. In this paper, the pathway and mechanism for ammonium oxidation with various electron acceptors under anaerobic condition is studied comprehensively, and the research progress of potentially functional microbes is summarized. The potential application of various electron acceptors for ammonium oxidation in wastewater is addressed, and the N2O emission during nitrogen removal is also discussed, which was important greenhouse gas for global climate change. The problems remained unclear for ammonium oxidation by multi-electron acceptors and potential interactions are also discussed in this review.
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Affiliation(s)
- Weizhuo Ye
- School of Environmental Science and Engineering, Guangzhou University, 510006, Guangzhou, P. R. China; Guangzhou University-Linköping University Research Center on Urban Sustainable Development, Guangzhou University, 510006, Guangzhou, China
| | - Jiaqi Yan
- School of Environmental Science and Engineering, Guangzhou University, 510006, Guangzhou, P. R. China; Guangzhou University-Linköping University Research Center on Urban Sustainable Development, Guangzhou University, 510006, Guangzhou, China
| | - Jia Yan
- School of Environmental Science and Engineering, Guangzhou University, 510006, Guangzhou, P. R. China; Guangzhou University-Linköping University Research Center on Urban Sustainable Development, Guangzhou University, 510006, Guangzhou, China.
| | - Jih-Gaw Lin
- Institute of Environmental Engineering, National Yang Ming Chiao Tung University, 1001 University Road, Hsinchu City, 30010, Taiwan
| | - Qixing Ji
- The Earth, ocean and atmospheric sciences thrust (EOAS), Hong Gong University of Science and Technology (Guangzhou), 511442, Guangzhou, P. R. China
| | - Zilei Li
- School of Environmental Science and Engineering, Guangzhou University, 510006, Guangzhou, P. R. China; Guangzhou University-Linköping University Research Center on Urban Sustainable Development, Guangzhou University, 510006, Guangzhou, China
| | - Hossein Ganjidoust
- Faculty of Civil and Environmental Engineering, Tarbiat Modarres University, 14115-397, Tehran, Iran
| | - Lei Huang
- School of Environmental Science and Engineering, Guangzhou University, 510006, Guangzhou, P. R. China; Guangzhou University-Linköping University Research Center on Urban Sustainable Development, Guangzhou University, 510006, Guangzhou, China
| | - Meng Li
- School of Environmental Science and Engineering, Guangzhou University, 510006, Guangzhou, P. R. China; Guangzhou University-Linköping University Research Center on Urban Sustainable Development, Guangzhou University, 510006, Guangzhou, China
| | - Hongguo Zhang
- School of Environmental Science and Engineering, Guangzhou University, 510006, Guangzhou, P. R. China; Guangzhou University-Linköping University Research Center on Urban Sustainable Development, Guangzhou University, 510006, Guangzhou, China
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Abstract
In this review, we describe recent research developments into radiation damage effects in macromolecular X-ray crystallography observed at synchrotrons and X-ray free electron lasers. Radiation damage in small molecule X-ray crystallography, small angle X-ray scattering experiments, microelectron diffraction, and single particle cryo-electron microscopy is briefly covered.
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Affiliation(s)
- Elspeth F Garman
- Department of Biochemistry, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford, OX1 3QU, UK.
| | - Martin Weik
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38044 Grenoble, France.
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Souidi S, Loap P, Laki F, Amessis M, Fourquet A, Kirova Y. Long-term efficacy and tolerance of a technique for postmastectomy electron beam radiation therapy of the unreconstructed chest wall and lymph node areas for non-metastatic breast cancers. Cancer Radiother 2023; 27:362-369. [PMID: 37169637 DOI: 10.1016/j.canrad.2023.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/12/2023] [Accepted: 04/13/2023] [Indexed: 05/13/2023]
Abstract
PURPOSE To evaluate the long-term tolerance and outcome of patients irradiated with an electron beam technique used since 2007 on the chest wall and lymph node areas after mastectomy for non-metastatic locally advanced breast carcinoma. PATIENTS AND METHODS All patients irradiated with an improved electron beam technique after mastectomy for non-metastatic breast carcinoma between 2007 and 2011 at Institut Curie (France) were included in this descriptive study. The technique has already been described in other studies, as has its 5-year tolerance and non-inferiority compared to photon irradiation. Acute and chronic toxicity were collected using CTCAE v 3.0. A clinical examination was carried out each week during the radiotherapy and at each 6 months consultation with one mammogram per year at the Institut Curie for at least 5 years. The patients then continued to be followed either at the Institut Curie or in private practice with a good transmission of outpatient consultations, thanks to a system of forms to be completed and integrated into the electronic files. Quantitative and qualitative data are defined by mean and proportion. Statistical comparisons were made by computer using the Chi2 test and Fisher's exact test for categorical variables. Recurrence-free survival was defined as the time between the end of treatment and the date of recurrence or death. Overall survival was defined in the same way without taking into account recurrences. Patients who did not report any events were censored at the date of last news. RESULTS Of the 796 patients included, 51.3% had multifocal lesions, 10.1% had triple negative status, and 18.8% displayed overexpression of the Her2 receptor, 196 (24.6%) patients received neoadjuvant chemotherapy and 208 (26.1%) systemic treatment during radiotherapy (chemotherapy or targeted therapy); 514 (64.6%) had at least one positive lymph node. The internal mammary chain (IMC) was irradiated in 85.6% of cases, the supraclavicular areas in 88.3% of cases, the infraclavicular in 77.9% of cases and the axillary area in 14.9% of cases. With a median follow-up of 113 months (range: 2-164 months), locoregional recurrence-free survival and overall 10-year survival was respectively 94.02%, (95% CI: 92.13-98.94) and 79.84% (95% CI: 76.83-82.97). Median survival was not reached. In the long term, 29.6% of patients had telangiectasias (grade 1: 23.3%, grade 2: 5.2%, grade 3: 1.1%). There were 279 patients (35.1%) with secondary breast reconstruction on average 21 months after all treatments. IMC irradiation was not associated with a majority of pulmonary toxicity. Thirty-five patients developed chronic heart disease after radiotherapy, 30 of whom had received anthracyclines and 9 had received traztuzumab. Three of these reported a coronary ischaemic event, including 2 irradiated on the left and 1 on the right, the 4 were irradiated in the vicinity of the IMC and the other lymph node areas, but presented many other cardiovascular risk factors (between 2 and 4). During follow-up, 4.9% of patients had a contralateral recurrence (n=39) and 5.5% had a second non-breast cancer (n=44), of the 6 bronchopulmonary cancers diagnosed, none appeared to be related to chest wall radiotherapy. CONCLUSION This study confirms that the improved postmastectomy electron beam radiation therapy technique is well-tolerated after nearly 10 years of follow-up.
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Affiliation(s)
- S Souidi
- Department of radiation oncology, Institut Curie, Paris, France
| | - P Loap
- Department of radiation oncology, Institut Curie, Paris, France
| | - F Laki
- Department of surgery, Institut Curie, Paris, France
| | - M Amessis
- Department of radiation oncology, Institut Curie, Paris, France
| | - A Fourquet
- Department of radiation oncology, Institut Curie, Paris, France
| | - Y Kirova
- Department of radiation oncology, Institut Curie, Paris, France; Université de Versailles-Saint-Quentin, Versailles, France.
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Diaz-Merchan JA, Martinez-Ovalle SA, Vega-Carrillo HR. Development of a 3D printing process of bolus using BolusCM material for radiotherapy with electrons. Appl Radiat Isot 2023; 199:110899. [PMID: 37321051 DOI: 10.1016/j.apradiso.2023.110899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/01/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023]
Abstract
This work presents the optimized parameters of 3D printing for print bolus using BolusCM material. Printing parameters were selected of the homogeneity and absence of air gaps. The dosimetric features of printed bolus were measured with a plane-parallel ionization chamber and EBT3 radiochromic film. Measured features were compared with those estimated with Monte Carlo methods. BolusCM shows good characteristics to be used as bolus material in radiotherapy with electrons, where the printing process allows personalizing the bolus in function of patient characteristics. The material low-cost, the 3D printing and the dosimetric features are few of the advantages of using BolusCM material in radiotherapy with electrons in skin cancer treatment.
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Affiliation(s)
- J A Diaz-Merchan
- Grupo de Física Nuclear Aplicada y Simulación Universidad Pedagógica y Tecnológica de Colombia, Avenida Central del Norte 39-115, Tunja, Boyacá, Colombia; Centro de Cancerología de Boyacá, Avenida Universitaria 46-7, Tunja, Boyacá, Colombia.
| | - S A Martinez-Ovalle
- Grupo de Física Nuclear Aplicada y Simulación Universidad Pedagógica y Tecnológica de Colombia, Avenida Central del Norte 39-115, Tunja, Boyacá, Colombia; Centro de Cancerología de Boyacá, Avenida Universitaria 46-7, Tunja, Boyacá, Colombia
| | - H R Vega-Carrillo
- Unidad Académica de Estudios Nucleares, Universidad Autónoma de Zacatecas, C. Cipres 10, Fracc. La Peñuela, 98060, Zacatecas, Zac, Mexico
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Demyashkin GA, Vadyukhin MA, Shekin VI. The Influence of Platelet-Derived Growth Factors on the Proliferation of Germinal Epithelium After Local Irradiation with Electrons. J Reprod Infertil 2023; 24:94-100. [PMID: 37547573 PMCID: PMC10402459 DOI: 10.18502/jri.v24i2.12494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 01/20/2023] [Indexed: 08/08/2023] Open
Abstract
Background At present, the damage of male reproductive function caused by electron irradiation, as well as the development of methods for its correction are the relevant topics for further research. In fact, the effect of leukocyte-poor platelet-rich plasma (LP-PRP) growth factors are poorly investigated on different aspects of male fertility. Methods In this study, Wistar rats were divided into four groups; I) control which were injected with saline; II and III) groups (n=65) whose testes were locally irradiated with electrons to a dose of 2 Gy (linear accelerator "NOVAC-11"); III) the group (n=30) which received LP-PRP for 11 weeks after irradiation; and IV) animals (n=30) which received only LP-PRP (conditional control). The testes were studied by histological, immunohistochemical (IHC), western blotting, and TUNEL methods using Ki-67, Bcl-2, and p53. Comparison between groups was performed and p<0.01 was set as the level of significance. Results The results showed a decrease in the expression levels of Ki-67 and Bcl-2 besides an increase in p53-positive cells by the end of the experiment (p<0.01). After injection of LP-PRP, a gradual restoration of the proliferative activity of gametes was noted, which was confirmed by an increase in the proportion of Ki-67- and Bcl-2-positive germ cells (46.4±2.3, p<0.01 and 23.5±1.1, respectively, p<0.01). Conclusion Ki-67 expression and TUNEL analysis in the testes revealed a modulation of the proliferative-apoptotic balance towards apoptosis of germ cells after 2 Gy local electron irradiation. A tendency to restore the proliferative-apoptotic balance was noted after LP-PRP injections as indicated by increase in Ki-67-positive germ cells.
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Affiliation(s)
- Grigory A Demyashkin
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
- A. Tsyb Medical Radiological Research Centre, Ministry of Health of Russian Federation, Obninsk, Russia
| | - Matvey A Vadyukhin
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Vladimir I Shekin
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
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Margis S, Kyriakou I, Incerti S, Bordage MC, Emfietzoglou D. Sub-keV corrections to binary encounter cross section models for electron ionization of liquid water with application to the Geant4-DNA Monte Carlo code. Appl Radiat Isot 2023; 194:110693. [PMID: 36731390 DOI: 10.1016/j.apradiso.2023.110693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/13/2022] [Accepted: 01/23/2023] [Indexed: 01/26/2023]
Abstract
INTRODUCTION The electron ionization cross section of water is one of the most important input in Monte Carlo studies of cellular radiobiological effects. Analytical cross section models of the binary-encounter type have the potential of reducing simulation time and facilitate application to a variety of biological materials (other than water). The Binary-Encounter-Bethe (BEB) and Binary-Encounter-Dipole (BED) models of NIST are perhaps the most popular of such models giving reliable results for atoms and molecules in the gas-phase over a wide energy range. However, the use of such models to sub-keV electron energies in liquid water raises concerns due to the neglect of condensed phase effects that leads to a significant overestimation when compared to medium-specific dielectric models. PURPOSE To modify the BEB and BED models towards better agreement with the recommended low-energy dielectric model of Geant4-DNA (Option 4). To implement the new modifications to the existing BEB model of the Option 6 physics constructor of Geant4-DNA and re-evaluate fundamental transport quantities for sub-keV electrons. METHODS In analogy to a Yukawa potential a simple, yet physically-motivated, modification of the Burgess correction term is proposed to account for the reduction of the Coulomb interaction due to the polarizability of the target. The magnitude of the correction is guided by the dielectric-based ionization cross section implemented in Option 4. RESULTS Differential, total and stopping ionization cross sections for low-energy electrons in liquid water are presented. When combined with the Vriens correction (which is not included in Option 6), the proposed modification to the BEB and BED models brings the ionization and stopping cross sections in much better agreement against those used in the Option 4 dielectric model of Geant4-DNA, with up to 30% and 10% deviation, respectively. Implementation of the new correction to the Option 6 constructor of Geant4-DNA and re-evaluation of fundamental transport quantities, such as electron penetration ranges and dose-point-kernels, reduced the discrepancies from Option 4 at sub-keV energies from 20 to 100% (or more) to well below 10% in most cases. CONCLUSIONS A simple modification to the BEB and BED analytic models was found to improve their performance for sub-keV electrons in liquid water medium. Implementation of the new modification to the Option 6 constructor of Geant4-DNA significantly improved the agreement with the recommended low-energy Option 4 constructor for a variety of fundamental quantities related to electron transport.
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Affiliation(s)
- Stefanos Margis
- Medical Physics Laboratory, University of Ioannina Medical School, 45110, Ioannina, Greece
| | - Ioanna Kyriakou
- Medical Physics Laboratory, University of Ioannina Medical School, 45110, Ioannina, Greece
| | - Sebastien Incerti
- Bordeaux University, CNRS/IN2P3, CENBG, UMR 5797, F-33170, Gradignan, France
| | | | - Dimitris Emfietzoglou
- Medical Physics Laboratory, University of Ioannina Medical School, 45110, Ioannina, Greece.
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Liu Y, Gao X, Cao X, Sakamaki T, Zhang C, Li X. Study on the performance and mechanism of bio-electrochemical system to mitigate membrane fouling in bioreactors. Bioresour Technol 2022; 365:128163. [PMID: 36283665 DOI: 10.1016/j.biortech.2022.128163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 10/13/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
To alleviate membrane fouling, a membrane of the membrane bioreactor was directly used as the anode of the bio-electrochemical system. On the 14th day, the control group had blocked, while the experimental group with a current of 0.44 mA, the increase in ΔTMP was only 2.2 kPa. The polysaccharide and protein concentrations in the open-circuit group were 4.2 and 2.9 times higher than those in the closed-circuit group, respectively. Three-dimensional fluorescence spectroscopy and gas chromatography mass spectrometry showed that most of the deposition in the control group contained high-molecular-weight compounds, especially long-chain ester derivatives, phenols, and complex hydrocarbons, whereas the experimental group was the opposite. Therefore, current (electrons) can change the composition of the cake layer. High-throughput sequencing indicated that a significantly higher abundance of electroactive microorganisms on the experimental than control group. Two-dimensional correlation spectroscopy showed that electrons promote the degradation of polysaccharides, thereby alleviating membrane fouling.
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Affiliation(s)
- Yanqing Liu
- College of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, PR China
| | - Xintong Gao
- College of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, PR China
| | - Xian Cao
- College of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, PR China; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Takashi Sakamaki
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Chong Zhang
- College of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, PR China
| | - Xianning Li
- College of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, PR China.
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Mochizuki J, Nakaura T, Matsumi H, Hata Y. Evaluation of coronavirus-2019-related arterial thrombosis in noncontrast spectral computed tomography with electron density imaging. Radiol Case Rep 2022; 18:49-52. [PMID: 36317095 PMCID: PMC9612951 DOI: 10.1016/j.radcr.2022.09.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 09/20/2022] [Accepted: 09/25/2022] [Indexed: 11/07/2022] Open
Abstract
Thrombosis can be associated with coronavirus disease 2019 infection. Computed tomography is essential for the diagnosis of pneumonia in these patients and conventionally contrast agents are required for the assessment of thrombus. In this study, we report a patient with coronavirus disease 2019 who was diagnosed with thrombosis using spectral noncontrast computed tomography with electron density imaging. The patient was a 76-year-old man who presented with a 2-day history of lower-leg pain. Tachycardia and atrial fibrillation were identified, with elevated D-dimer, N-terminal pro-B-type natriuretic peptide, creatine kinase, and C-reactive protein levels. Polymerase chain reaction testing for severe acute respiratory syndrome coronavirus-2 was positive. Conventional computed tomography showed pulmonary changes consistent with coronavirus disease 2019 and no changes in the aorta, but spectral computed tomography with electron density imaging of noncontrast computed tomography showed a thrombus in the right external iliac artery. Spectral computed tomography with electron density imaging provides more data compared with conventional computed tomography and has the potential to depict thrombus without the use of contrast media.
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Affiliation(s)
- Junji Mochizuki
- Department of Radiology, Minamino Cardiovascular Hospital, 1-25-1 Hyoue, Hachioji, Tokyo 192-0918, Japan
- Corresponding author.
| | - Takeshi Nakaura
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Hiroaki Matsumi
- Department of Cardiology, Minamino Cardiovascular Hospital, 1-25-1 Hyoue, Hachioji, Tokyo 192-0918, Japan
| | - Yoshiki Hata
- Department of Cardiology, Minamino Cardiovascular Hospital, 1-25-1 Hyoue, Hachioji, Tokyo 192-0918, Japan
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11
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van Aalst ACA, Mans R, Pronk JT. An engineered non-oxidative glycolytic bypass based on Calvin-cycle enzymes enables anaerobic co-fermentation of glucose and sorbitol by Saccharomyces cerevisiae. Biotechnol Biofuels Bioprod 2022; 15:112. [PMID: 36253796 DOI: 10.1186/s13068-022-02200-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/17/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND Saccharomyces cerevisiae is intensively used for industrial ethanol production. Its native fermentation pathway enables a maximum product yield of 2 mol of ethanol per mole of glucose. Based on conservation laws, supply of additional electrons could support even higher ethanol yields. However, this option is disallowed by the configuration of the native yeast metabolic network. To explore metabolic engineering strategies for eliminating this constraint, we studied alcoholic fermentation of sorbitol. Sorbitol cannot be fermented anaerobically by S. cerevisiae because its oxidation to pyruvate via glycolysis yields one more NADH than conversion of glucose. To enable re-oxidation of this additional NADH by alcoholic fermentation, sorbitol metabolism was studied in S. cerevisiae strains that functionally express heterologous genes for ribulose-1,5-bisphosphate carboxylase (RuBisCO) and phosphoribulokinase (PRK). Together with the yeast non-oxidative pentose-phosphate pathway, these Calvin-cycle enzymes enable a bypass of the oxidative reaction in yeast glycolysis. RESULTS Consistent with earlier reports, overproduction of the native sorbitol transporter Hxt15 and the NAD+-dependent sorbitol dehydrogenase Sor2 enabled aerobic, but not anaerobic growth of S. cerevisiae on sorbitol. In anaerobic, slow-growing chemostat cultures on glucose-sorbitol mixtures, functional expression of PRK-RuBisCO pathway genes enabled a 12-fold higher rate of sorbitol co-consumption than observed in a sorbitol-consuming reference strain. Consistent with the high Km for CO2 of the bacterial RuBisCO that was introduced in the engineered yeast strains, sorbitol consumption and increased ethanol formation depended on enrichment of the inlet gas with CO2. Prolonged chemostat cultivation on glucose-sorbitol mixtures led to loss of sorbitol co-fermentation. Whole-genome resequencing after prolonged cultivation suggested a trade-off between glucose-utilization and efficient fermentation of sorbitol via the PRK-RuBisCO pathway. CONCLUSIONS Combination of the native sorbitol assimilation pathway of S. cerevisiae and an engineered PRK-RuBisCO pathway enabled RuBisCO-dependent, anaerobic co-fermentation of sorbitol and glucose. This study demonstrates the potential for increasing the flexibility of redox-cofactor metabolism in anaerobic S. cerevisiae cultures and, thereby, to extend substrate range and improve product yields in anaerobic yeast-based processes by enabling entry of additional electrons.
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12
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Souza-Corrêa JA, da Silveira EF. Space Weathering: Processing Velocities in Organic Materials as a Function of Electron Beam Energies-Solar Electron Erosion Rate Application. Astrobiology 2022; 22:800-811. [PMID: 35639110 DOI: 10.1089/ast.2021.0133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Samples of α-glycine (α-GLY; 230-350 nm) were irradiated in laboratory as a function of electron beam energies (0.25, 0.50, and 1.00 keV) at room temperature (293-295 K). The evolution of α-glycine irradiation process was monitored in real time by infrared spectroscopy (Fourier transform infrared - FTIR), through specific spectral bands: 2610, 2124, 1410, and 1333 cm-1. A phenomenological model is proposed to describe the column density decay when thick organic samples are processed by ionizing beams. The α-glycine radiolysis has exhibited transient and stationary modes in such thickness films. The first stage is mainly described by one exponential decay, whereas the latter foremost decays linearly; compaction processes have been neglected; glycine dissociation and sputtering processes are assumed to be responsible for the damage caused by the electron beam impact through the solid film. The second (stationary) stage is due to equilibrium between a partially shielded bulk radiolysis and sputtering of protective layers. The decay rates are measured for the transient and stationary modes and allow determining the processing velocity of the samples as a function of the electron beam energy. Finally, the model is applied to space weathering to find out the typical sputtering rate of organic compounds on the surface of astrophysical analogs with no protection layers attacked by solar wind (SW) electrons at ≈1 AU. Although the velocity of processing materials in SW has natural competing effects, such as regolith overturn by impacts of micro- and macrometeorites and downslope motion of material that is unstable due to changes in the geopotential of the airless bodies (e.g., asteroid 101955 Bennu), these competing processes are not included in the simulations presented here.
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Affiliation(s)
- J A Souza-Corrêa
- Van de Graaff Laboratory, Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro (PUC-RIO), Rio de Janeiro, Brazil
| | - E F da Silveira
- Van de Graaff Laboratory, Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro (PUC-RIO), Rio de Janeiro, Brazil
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Djiepmo F, Tamaskovics B, Bölke E, Peiper M, Haussmann J, Neuwahl J, Jazmati D, Maas K, Schmidt L, Gelzhäuser R, Schleich C, Corradini S, Orth K, van Griensven M, Rezazadeh A, Karimi K, Budach W, Matuschek C. Low-dose radiation treatment for painful plantar enthesophyte: a highly effective therapy with little side effects. Eur J Med Res 2022; 27:28. [PMID: 35197107 PMCID: PMC8867737 DOI: 10.1186/s40001-022-00642-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 01/13/2022] [Indexed: 12/02/2022] Open
Abstract
AIM Plantar enthesophyte is a common degenerative disorder. Surgical and medical treatment options are associated with either poor outcome or high percentage of relapse. Observations have indicated a beneficial effect of radiation therapy. We therefore wanted to evaluate pain reduction using orthovolt or cobalt-based radiation treatment for painful plantar enthesophyte and determine long-term response as well as prognostic parameters in this condition. METHODS We identified a total of 102 consecutive patients treated for a total of 117 symptomatic heel spurs. 59 patients were treated with cobalt radiation, 31 patients with orthovolt therapy and 12 patients with both radiation systems. Primary outcome measure was pain reduction being scored using the modified Rowe Score prior therapy, at the end of each treatment series as well as after 6 weeks. Secondary outcome measure was long-term outcome, evaluated in patients with a follow-up period of longer than 3 years. RESULTS Before radiation therapy, 61 patients (60.4%) had a score of 0, significant strong pain. At the time of completion of radiation treatment, 3 patients (2.7%) were pain-free (score of 30), whereas 8 patients (7.9%) had still severe pain (score 0). 6 weeks after radiation therapy, 33 patients (32.7%) were pain-free and 8 patients (7.9%) had severe pain (score 0), while at the time data of collection, 74 patients (73%) were free of pain and 1 patient (1%) had strong pain (score 0). Duration of pain before the start of radiation treatment was a significant prognostic factor (p = 0.012) for response to treatment. CONCLUSION Radiotherapy of painful plantar enthesophyte is a highly effective therapy with little side effects providing long-term therapeutic response. The only significant prognostic parameter for response to treatment is the duration of pre-radiation therapy pain. Early integration of radiation therapy in the treatment seems to result in superior pain reduction.
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Affiliation(s)
- Freddy Djiepmo
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Bálint Tamaskovics
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Edwin Bölke
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
- Klinik Für Strahlentherapie Und Radiologische Onkologie, Heinrich-Heine-Universität, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Matthias Peiper
- Medical Faculty, Heinrich-Heine-University, Dusseldorf, Germany
| | - Jan Haussmann
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Judith Neuwahl
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Danny Jazmati
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Kitti Maas
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Livia Schmidt
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Roman Gelzhäuser
- Institute of Mathematical Statistics and Probability Theory, Heinrich-Heine-University, Dusseldorf, Germany
| | - Christoph Schleich
- Radiology Dusseldorf/Viersen, Ernst-Schneider-Platz 1, Dusseldorf, Germany
| | - Stefanie Corradini
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - Klaus Orth
- University of Hannover, Hannover, Germany
| | - Martijn van Griensven
- Department cBITE, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, The Netherlands
| | - Amir Rezazadeh
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Kimia Karimi
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Wilfried Budach
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
| | - Christiane Matuschek
- Department of Radiation Oncology, Heinrich Heine University, Dusseldorf, Germany
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Ryu B, Wong KT, Choong CE, Kim JR, Kim H, Kim SH, Jeon BH, Yoon Y, Snyder SA, Jang M. Degradation synergism between sonolysis and photocatalysis for organic pollutants with different hydrophobicity: A perspective of mechanism and application for high mineralization efficiency. J Hazard Mater 2021; 416:125787. [PMID: 33862480 DOI: 10.1016/j.jhazmat.2021.125787] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/23/2021] [Accepted: 03/27/2021] [Indexed: 06/12/2023]
Abstract
Despite extensive studies, the fundamental understanding of synergistic mechanisms between sonolysis and photocatalysis for the abatement of persistent organic pollutants (POPs) remains uncertain. As different phases formed under ultrasound irradiation, hydrophilic POPs, sulfamethoxazole (SMX, Kow: 0.89), predominantly resides in bulk liquid and is ineffectively degraded by sonolysis (kUS = 3.33 × 10-3 min-1) since <10% of hydroxyl radicals (·OH) formed at the gas-liquid interface of cavitation is diffused into the bulk, whereas the other fraction rapidly recombines into hydrogen peroxide (H2O2). This study provides a proof-of-concept for the mechanism by presenting various analytical results, endorsing the synergistic role of photoexcited electrons in splitting sonolysis-induced H2O2 into ·OH, particularly in the bulk phase. In a sonophotocatalytic system, the hydrophobic POPs such as bisphenol A (BPA) and atrazine (ATZ) were mainly degraded in gas-liquid interface indicated by the low synergistic values correlation compared to SMX [i.e., SMX has a higher synergistic factor, fsyn (3.26) than BPA (1.30) and ATZ (1.35)]. Also, fsyn was found linearly correlated with the contribution factor of photocatalysis to split H2O2. Three times of consecutive kinetics using an effluent of municipal (MP) wastewater spiked by POPs presented >98% POPs and >96% total organic carbon (TOC) removal.
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Affiliation(s)
- Baekha Ryu
- Department of Environmental Engineering, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul 01897, Republic of Korea
| | - Kien Tiek Wong
- Department of Environmental Engineering, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul 01897, Republic of Korea.
| | - Choe Earn Choong
- Department of Environmental Engineering, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul 01897, Republic of Korea
| | - Jung-Rae Kim
- School of Chemical and Biomolecular Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Hyunook Kim
- Department of Environmental Engineering, University of Seoul, Seoul 02504, Republic of Korea
| | - Sang-Hyoun Kim
- Department of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Byong-Hun Jeon
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul 04763, Republic of Korea
| | - Yeomin Yoon
- Department of Civil and Environmental Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208, USA
| | - Shane A Snyder
- Chemical and Environmental Engineering, University of Arizona, Tucson, AZ 85721, USA; Nanyang Environment & Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141, Singapore
| | - Min Jang
- Department of Environmental Engineering, Kwangwoon University, 20 Kwangwoon-Ro, Nowon-Gu, Seoul 01897, Republic of Korea.
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Verscharen D, Wicks RT, Alexandrova O, Bruno R, Burgess D, Chen CHK, D’Amicis R, De Keyser J, de Wit TD, Franci L, He J, Henri P, Kasahara S, Khotyaintsev Y, Klein KG, Lavraud B, Maruca BA, Maksimovic M, Plaschke F, Poedts S, Reynolds CS, Roberts O, Sahraoui F, Saito S, Salem CS, Saur J, Servidio S, Stawarz JE, Štverák Š, Told D. A Case for Electron-Astrophysics. Exp Astron (Dordr) 2021; 54:473-519. [PMID: 36915623 PMCID: PMC9998602 DOI: 10.1007/s10686-021-09761-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 05/07/2021] [Indexed: 06/18/2023]
Abstract
The smallest characteristic scales, at which electron dynamics determines the plasma behaviour, are the next frontier in space and astrophysical plasma research. The analysis of astrophysical processes at these scales lies at the heart of the research theme of electron-astrophysics. Electron scales are the ultimate bottleneck for dissipation of plasma turbulence, which is a fundamental process not understood in the electron-kinetic regime. In addition, plasma electrons often play an important role for the spatial transfer of thermal energy due to the high heat flux associated with their velocity distribution. The regulation of this electron heat flux is likewise not understood. By focussing on these and other fundamental electron processes, the research theme of electron-astrophysics links outstanding science questions of great importance to the fields of space physics, astrophysics, and laboratory plasma physics. In this White Paper, submitted to ESA in response to the Voyage 2050 call, we review a selection of these outstanding questions, discuss their importance, and present a roadmap for answering them through novel space-mission concepts.
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Affiliation(s)
- Daniel Verscharen
- Mullard Space Science Laboratory, University College London, Dorking, UK
- Space Science Center, University of New Hampshire, Durham, NH USA
| | - Robert T. Wicks
- Mullard Space Science Laboratory, University College London, Dorking, UK
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle-upon-Tyne, UK
| | - Olga Alexandrova
- Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique, Observatoire de Paris-Meudon, Paris, France
| | - Roberto Bruno
- Instituto di Astrofisica e Planetologia Spaziali, INAF, Rome, Italy
| | - David Burgess
- School of Physics and Astronomy, Queen Mary University of London, London, UK
| | | | | | - Johan De Keyser
- Royal Belgian Institute for Space Aeronomy, Brussels, Belgium
| | - Thierry Dudok de Wit
- Laboratoire de Physique et Chimie de l’Environment et de l’Espace, CNRS, University of Orléans and CNES, Orléans, France
| | - Luca Franci
- School of Physics and Astronomy, Queen Mary University of London, London, UK
- Osservatorio Astrofisico di Arcetri, INAF, Firenze, Italy
| | - Jiansen He
- School of Earth and Space Sciences, Peking University, Beijing, China
| | - Pierre Henri
- Laboratoire de Physique et Chimie de l’Environment et de l’Espace, CNRS, University of Orléans and CNES, Orléans, France
- CNRS, UCA, OCA, Lagrange, Nice, France
| | - Satoshi Kasahara
- Department of Earth and Planetary Science, University of Tokyo, Tokyo, Japan
| | | | - Kristopher G. Klein
- Lunar and Planetary Laboratory and Department of Planetary Sciences, University of Arizona, Tucson, AZ USA
| | - Benoit Lavraud
- Laboratoire d’astrophysique de Bordeaux, Université de Bordeaux, CNRS, Pessac, France
- Institut de Recherche en Astrophysique et Planétologie, CNRS, UPS, CNES, Université de Toulouse, Toulouse, France
| | - Bennett A. Maruca
- Department of Physics and Astronomy, Bartol Research Institute, University of Delaware, Newark, DE USA
| | - Milan Maksimovic
- Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique, Observatoire de Paris-Meudon, Paris, France
| | | | - Stefaan Poedts
- Centre for Mathematical Plasma Astrophysics, KU Leuven, Leuven, Belgium
- Institute of Physics, University of Maria Curie-Skłodowska, Lublin, Poland
| | | | - Owen Roberts
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| | - Fouad Sahraoui
- Laboratoire de Physique des Plasmas, CNRS, École Polytechnique, Sorbonne Université, Observatoire de Paris-Meudon, Paris Saclay, Palaiseau, France
| | - Shinji Saito
- Space Environment Laboratory, National Institute of Information and Communications Technology, Tokyo, Japan
| | - Chadi S. Salem
- Space Sciences Laboratory, University of California, Berkeley, CA USA
| | - Joachim Saur
- Institut für Geophysik und Meteorologie, University of Cologne, Cologne, Germany
| | - Sergio Servidio
- Department of Physics, Università della Calabria, Rende, Italy
| | | | - Štěpán Štverák
- Astronomical Institute and Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - Daniel Told
- Max Planck Institute for Plasma Physics, Garching, Germany
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Van Schelt J. Lens dose to standing patients treated with electrons to the hand. Med Dosim 2021; 46:e7-e10. [PMID: 34053855 DOI: 10.1016/j.meddos.2021.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/13/2021] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
Patients receiving radiotherapy to the hand are sometimes treated standing, with their heads beside and potentially facing an electron applicator. This raises the possibility of consequential lens dose from scattered electrons, which this study investigates. This study measures the dose beside an applicator at a depth of 3 mm in a phantom as an estimate of lens dose for such patients. The lens dose is investigated as a function of height, distance, beam energy, applicator size, and cutout fill on a Varian Trilogy linear accelerator. The effect of the potential mitigation strategies of turning the head or shielding with lead sheets is also investigated. Measurement found that a typical hand setup may result in the lens receiving 0.15% of the treatment dose, which would deliver a cumulative dose above the demonstrated threshold dose for cataract risk for some courses. Large applicators and close facial proximity to the applicator separately enhance dose by factors of 3 and 5 respectively, raising the possibility of multiple gray to the lens for patients in unfavorable setups. Simple and effective mitigation strategies are available: Turning the patient's head to the side or placing 1-2 mm of lead on glasses reduced lens dose by a factor of 3-4, and covering the side of the applicator with 1 mm of lead or turning the head completely away effectively eliminated lens dose. The lens dose can be consequential but is readily mitigated.
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Affiliation(s)
- Jonathon Van Schelt
- Department of Radiation Oncology, Rush University Medical Center, Chicago, IL 60612-3833, USA.
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Ciabattoni A, Gregucci F, Fastner G, Cavuto S, Spera A, Drago S, Ziegler I, Mirri MA, Consorti R, Sedlmayer F. IOERT versus external beam electrons for boost radiotherapy in stage I/II breast cancer: 10-year results of a phase III randomized study. Breast Cancer Res 2021; 23:46. [PMID: 33849606 PMCID: PMC8045244 DOI: 10.1186/s13058-021-01424-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/31/2021] [Indexed: 01/09/2023] Open
Abstract
Background Intraoperative radiotherapy with electrons (IOERT) boost could be not inferior to external beam radiotherapy (EBRT) boost in terms of local control and tissue tolerance. The aim of the study is to present the long-term follow-up results on local control, esthetic evaluation, and toxicity of a prospective study on early-stage breast cancer patients treated with breast-conserving surgery with an IOERT boost of 10 Gy (experimental group) versus 5 × 2 Gy EBRT boost (standard arm). Both arms received whole-breast irradiation (WBI) with 50 Gy (2 Gy single dose). Methods A single-institution phase III randomized study to compare IOERT versus EBRT boost in early-stage breast cancer was conducted as a non-inferiority trial. Primary endpoints were the evaluation of in-breast true recurrences (IBTR) and out-field local recurrences (LR) as well as toxicity and cosmetic results. Secondary endpoints were overall survival (OS), disease-free survival (DFS), and patient’s grade of satisfaction with cosmetic outcomes. Results Between 1999 and 2004, 245 patients were randomized: 133 for IOERT and 112 for EBRT. The median follow-up was 12 years (range 10–16 years). The cumulative risk of IBTR at 5–10 years was 0.8% and 4.3% after IOERT, compared to 4.2% and 5.3% after EBRT boost (p = 0.709). The cumulative risk of out-field LR at 5–10 years was 4.7% and 7.9% for IOERT versus 5.2% and 10.3% for EBRT (p = 0.762). All of the IOERT arm recurrences were observed at > 100 months’ follow-up, whereas the mean time to recurrence in the EBRT group was earlier (55.2 months) (p < 0.05). No late complications associated with IOERT were observed. The overall cosmetic results were scored as good or excellent in physician and patient evaluations for both IOERT and EBRT. There were significantly better scores for IOERT at all time points in physician and patient evaluations with the greatest difference at the end of EBRT (p = 0.006 objective and p = 0.0004 subjective) and most narrow difference at 12 months after the end of EBRT (p = 0.08 objective and p = 0.04 subjective analysis). Conclusion A 10-Gy IOERT boost during breast-conserving surgery provides high local control rates without significant morbidity. Although not significantly superior to external beam boosts, the median time to local recurrences after IOERT is prolonged by more than 4 years.
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Affiliation(s)
| | - Fabiana Gregucci
- Department of Radiation Oncology, Miulli General Regional Hospital, Acquaviva delle Fonti, Bari, Italy.
| | - Gerd Fastner
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Silvio Cavuto
- Infrastructure Research and Statistics, Clinical Trials and Statistics Unit, AUSL-IRCCS, Reggio Emilia, Italy
| | - Antonio Spera
- Department of Radiotherapy, San Giovanni di Dio Hospital, ASP Agrigento, Agrigento, Italy
| | - Stefano Drago
- Department of Breast and Reconstructive Surgery, Sando Pertini Hospital, Rome, Italy
| | - Ingrid Ziegler
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | | | - Rita Consorti
- Medical Physics Unit, San Filippo Neri Hospital, ASL Roma 1, Rome, Italy
| | - Felix Sedlmayer
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
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Munoz-Cupa C, Hu Y, Xu C, Bassi A. An overview of microbial fuel cell usage in wastewater treatment, resource recovery and energy production. Sci Total Environ 2021; 754:142429. [PMID: 33254845 DOI: 10.1016/j.scitotenv.2020.142429] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/04/2020] [Accepted: 09/15/2020] [Indexed: 06/12/2023]
Abstract
Wastewater treatment is a high-cost and energy-intensive process not only due to large amounts of pollutants but also for the large volumes of water to be treated, which are mainly generated by human activities and different industries. In this regard, biological wastewater treatments have become substitutes to the current technologies, owing to the improved treatment efficiency and added value. Microbial fuel cells (MFCs) as one of the promising biological treatments have arisen as a viable solution for chemical oxygen demand (COD) removal and electricity generation simultaneously. Therefore, in this article, the effects of various operating conditions on the COD removal and power production from MFCs are thoroughly discussed. In addition, the advantages and weaknesses of current MFCs technologies used for different types of wastewater are summarized. Finally, the technical barriers facing by MFCs operation and the economic feasibility of using MFCs for wastewater treatment are provided.
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Affiliation(s)
- Carlos Munoz-Cupa
- Department of Chemical and Biochemical Engineering, Western University, London, ON N6A 0A7, Canada
| | - Yulin Hu
- Department of Chemical and Biochemical Engineering, Western University, London, ON N6A 0A7, Canada.
| | - Chunbao Xu
- Department of Chemical and Biochemical Engineering, Western University, London, ON N6A 0A7, Canada
| | - Amarjeet Bassi
- Department of Chemical and Biochemical Engineering, Western University, London, ON N6A 0A7, Canada.
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H D, A A M, M G, S M, C K. Study of Photoneutron Production for the 18 MV Photon Beam of the Siemens Medical linac by Monte Carlo Simulation. J Biomed Phys Eng 2020; 10:679-690. [PMID: 33364205 PMCID: PMC7753258 DOI: 10.31661/jbpe.v0i0.939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 06/05/2018] [Indexed: 11/22/2022]
Abstract
Background: Considering the importance of photoneutron production in linear accelerators, it is necessary to describe and measure the photoneutrons produced around modern linear accelerators. Objective: The aim of the present research is to study photoneutron production for the 18 MV photon beam of a Siemens Primus Plus medical linear accelerator. Material and Methods: This study is an experimental study. The main components of the head of Siemens Primus Plus linac were simulated using MCNPX 2.7.0 code. The contribution of different components of the linac in photoneutron production, neutron source strength, neutron source strength and photon and electron spectra were calculated for the flattening filter and flattening filter free cases for the 18 MV photon beam, and was scored for three fields of 5 × 5 cm2, 10 × 10 cm2 and 20 × 20 cm2 in size. Results: The results show that the primary collimator has the largest contribution to production of neutrons. Moreover, the photon fluence for the flattening filter free case is 8.62, 6.51 and 4.62 times higher than the flattening filter case for the three fields, respectively. The electron fluences for the flattening filter free case are 4.62, 2.93 and 2.79 times higher than with flattening filter case for the three fields under study, respectively. In addition to these cases, by increasing the field size, the contribution of neutron production related to the jaws is reduced, so that when the field size increases from 5 × 5 cm2 to 20 × 20 cm2, a 17.93% decrease in photoneutron production was observed. Conclusion: In all of the accelerators, the neutron strength also increases with increasing energy. The calculated neutron strength was equal to 0.83×1012 neutron Gy −1 at the isocenter.
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Affiliation(s)
- Dowlatabadi H
- PhD, Physics Department, School of Sciences, Payame Noor University of Mashhad, Mashhad, Iran
| | - Mowlavi A A
- PhD, Physics Department, School of Sciences, Hakim Sabzevari University, Sabzevar, Iran
- PhD, International Centre for Theoretical Physics, Associate Federation Scheme, Medical Physics Field, Trieste, Italy
| | - Ghorbani M
- PhD, Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammadi S
- PhD, Physics Department, School of Sciences, Payame Noor University of Mashhad, Mashhad, Iran
| | - Knaup C
- PhD, Comprehensive Cancer Centers of Nevada, Las Vegas, Nevada, USA
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S N, M A, A A, F F, P S. Evaluation of Therapeutic Properties of a Low Energy Electron Beam Plus Spoiler for Local Treatment of Mycosis Fungoides: A Monte Carlo Study. J Biomed Phys Eng 2020; 10:441-448. [PMID: 32802792 PMCID: PMC7416096 DOI: 10.31661/jbpe.v0i0.712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 02/10/2017] [Indexed: 11/16/2022]
Abstract
Background: When using low-energy electron beams for the treatment of skin lesions, such as Mycosis Fungoides (MF), a beam spoiler
is used to decrease electron therapeutic depth (R90) while increasing the surface dose. Objective: The aim of this study was to evaluate the characteristics of a 5 MeV electron beam when using a spoiler for the local treatment of MF skin lesions by Monte Carlo (MC) simulation. Material and Methods: In this experimental study, a Siemens Primus treatment head and an acrylic spoiler, positioned at the end of applicator,
were simulated using BEAMnrc, an EGSnrc user code. The modelled beam was validated by measurement using MP3-M water tank,
Roos parallel plate chamber and Semi flex Chamber-31013 (all from PTW, Freiburg, Germany). For different spoiler thicknesses, dose distributions in water were calculated for 2 field sizes and were compared to those for the corresponding open fields. Results: For a 1.3 cm spoiler, therapeutic range changed from 1.5 cm (open field) to 0.5 cm and 0.4 cm for 10 × 10 cm2 and 20 × 20 cm2 field sizes,
respectively. Maximum increase in penumbra width was 2.8 and 3.8 cm for 10 × 10 cm2 and 20 × 20 cm2 field sizes, respectively. Maximum increase in bremsstrahlung contamination was %2 in both field sizes. Conclusion: R90 decreased exponentially with increase in spoiler thickness. The effect of field size on penumbra was much larger for spoiled beam compared to the open beam. The results of this research can be applied to optimize the radiation treatment of MF patients in our hospital.
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Affiliation(s)
- Noshadi S
- MSc, Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Atarod M
- PhD, Department of Medical Physics and Radiology, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Amouheidari A
- MD, Department of Radiation Oncology, Milad Hospital, Isfahan, Iran
| | - Felfeliyan F
- MSc, Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Shokrani P
- PhD, Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Pérez-Calatayud J, Sanchis-Sánchez E, Collado J, González V, Pérez-Calatayud I, Pérez-Calatayud MJ, Chimeno J, Carmona V, Luis Bonet-Sancho J, García-Sánchez AJ, Sanchis E. Phantom development for daily checks in electron intraoperative radiotherapy with a mobile linac. Phys Med 2020; 76:109-116. [PMID: 32673822 DOI: 10.1016/j.ejmp.2020.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 07/03/2020] [Accepted: 07/05/2020] [Indexed: 11/29/2022] Open
Abstract
PURPOSE IORT with mobile linear accelerators is a well-established modality where the dose rate and, therefore, the dose per pulse are very high. The constancy of the dosimetric parameters of the accelerator has to be checked daily. The aim of this work is to develop a phantom with embedded detectors to improve both accuracy and efficiency in the daily test of an IORT linac at the surgery room. METHODS The developed phantom is manufactured with transparent polymethyl methacrylate (PMMA), allocating 6 parallel-plate chambers: a central one to evaluate the on-axis beam output, another on-axis one placed at a fixed depth under the previous one to evaluate the energy constancy and four off-axis chambers to evaluate the flatness and symmetry. To analyse the readings a specific application has been developed. RESULTS For all chambers and energies, the mean saturation and polarization corrections were smaller than 0.7%. The beam is monitored at different levels of the clinical beam. Output, energy constancy and flatness correlate very well with the correspondent values with the complete applicator. During the first six months of clinical use the beam dosimetric parameters showed excellent stability. CONCLUSIONS A phantom has been developed with embedded parallel plate chambers attached to the upper applicator part of an IORT linac. The phantom allows a very efficient setup reducing the time to check the parameters. It provides complete dosimetric information (output, energy and flatness) with just one shot and using ionization chambers with minimum saturation effect, as this highly pulsed beam requires.
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Affiliation(s)
- José Pérez-Calatayud
- Department of Radiation Oncology, La Fe Polytechnic and University Hospital, Valencia, Spain
| | | | - Javier Collado
- Department of Electronic Engineering, University of Valencia, Spain
| | - Vicente González
- Department of Electronic Engineering, University of Valencia, Spain
| | - I Pérez-Calatayud
- Department of Electronic Engineering, University of Valencia, Spain.
| | - M J Pérez-Calatayud
- Department of Radiation Oncology, Fundación Instituto Valenciano de Oncología, Valencia, Spain
| | - José Chimeno
- Department of Radiation Oncology, La Fe Polytechnic and University Hospital, Valencia, Spain
| | - Vicente Carmona
- Department of Radiation Oncology, La Fe Polytechnic and University Hospital, Valencia, Spain
| | | | | | - Enrique Sanchis
- Department of Electronic Engineering, University of Valencia, Spain
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22
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Morganti S, Bertani E, Bocci V, Colandrea M, Collamati F, Cremonesi M, De Simoni M, Ferrari E, Fischetti M, Funicelli L, Grana CM, Mancini-Terracciano C, Mirabelli R, Papi S, Pisa E, Solfaroli-Camillocci E, Traini G, Faccini R. Tumor-non-tumor discrimination by a β - detector for Radio Guided Surgery on ex-vivo neuroendocrine tumors samples. Phys Med 2020; 72:96-102. [PMID: 32247965 DOI: 10.1016/j.ejmp.2020.03.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 01/06/2023] Open
Abstract
This paper provides a first insight of the potential of the β- Radio Guided Surgery (β--RGS) in a complex surgical environment like the abdomen, where multiple sources of background concur to the signal at the tumor site. This case is well reproduced by ex-vivo samples of 90Y-marked Gastro-Entero-Pancreatic Neuroendocrine Tumors (GEP NET) in the bowel. These specimens indeed include at least three wide independent sources of background associated to three anatomical districts (mesentery, intestine, mucose). The study is based on the analysis of 37 lesions found on 5 samples belonging to 5 different patients. We show that the use of electrons, a short range particle, instead of γ particles, allows to limit counts read on a lesion to the sum of the tumor signal plus the background generated by the sole hosting district.The background on adjacent districts in the same specimen/patient is found to differ up to a factor 4, showing how the specificity and sensitivity of the β--RGS technique can be fully exploited only upon a correct measurement of the contributing background. This locality has been used to set a site-specific cut-off algorithm to discriminate tumor and healthy tissue with a specificity of 100% and a sensitivity, on this test data sample, close to 100%. Factors influencing the sensitivity are also discussed. One of the specimens set allowed us evaluate the volume of the lesions, thus concluding that the probe was able to detect lesions as small as 0.04 mL in that particular case.
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Affiliation(s)
- S Morganti
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy
| | - E Bertani
- Division of Digestive Surgery, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - V Bocci
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy
| | - M Colandrea
- Division of Nuclear Medicine, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - F Collamati
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy.
| | - M Cremonesi
- Radiation Research Unit, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - M De Simoni
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy; Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy
| | - E Ferrari
- Division of Medical Physics, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - M Fischetti
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy; Dipartimento Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Rome, Italy
| | - L Funicelli
- Division of Radiology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - C M Grana
- Division of Nuclear Medicine, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - C Mancini-Terracciano
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy; Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy
| | - R Mirabelli
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy; Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy; Dipartimento Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Rome, Italy; Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Rome, Italy
| | - S Papi
- Division of Nuclear Medicine, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - E Pisa
- Division of Pathology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - E Solfaroli-Camillocci
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy; Scuola di Specializzazione in Fisica Medica, Sapienza Università di Roma, Rome, Italy
| | - G Traini
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy; Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy; Dipartimento Scienze di Base e Applicate per l'Ingegneria, Sapienza Università di Roma, Rome, Italy; Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Rome, Italy
| | - R Faccini
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Rome, Italy; Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy
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Fastner G, Reitsamer R, Urbański B, Kopp P, Murawa D, Adamczyk B, Karzcewska A, Milecki P, Hager E, Reiland J, Ciabattoni A, Matuschek C, Budach W, Nowell K, Schumacher C, Ricke A, Fusco V, Vidali C, Alessandro M, Ivaldi GB, Ziegler I, Fussl C, Zehentmayr F, Grambozov B, Sir A, Hitzl W, Ricardi U, Sedlmayer F. Toxicity and cosmetic outcome after hypofractionated whole breast irradiation and boost-IOERT in early stage breast cancer (HIOB): First results of a prospective multicenter trial (NCT01343459). Radiother Oncol 2020; 146:136-142. [PMID: 32151790 DOI: 10.1016/j.radonc.2020.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/27/2020] [Accepted: 02/03/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND AND PURPOSE To assess the role of intraoperative radiation with electrons (IOERT) as tumor bed boost followed by hypofractionated whole breast irradiation (HWBI) after breast conserving surgery (BCS) of patients with low to intermediate risk breast cancer focusing on acute/late toxicity and cosmetic outcome. MATERIAL AND METHODS In 2011, a prospective multicenter trial (NCT01343459) was started. Treatment consisted of BCS, IOERT (11.1 Gy) and HWBI (40.5 Gy in 15 fractions). In a single-arm design, 5-year IBR-rates are benchmarked by a sequential ratio test (SQRT) against best published evidences in 3 age groups (35-40 y, 41-50 y, >50 y). Acute/late toxicity and cosmesis were evaluated by validated scorings systems. RESULTS Of 627 eligible patients, 44 were excluded, leaving 583 to analyze. After a median follow-up (FUP) of 45 months (range 0-74), for acute effects CTCAE-score 0/1 was noted in 91% (end of HWBI) and 92% (4 weeks later), respectively. Late toxicity Grading 0/1 (mean values, ranges) by LENT-SOMA criteria were observed in 92.7% (89-97.3) at 4/5 months, rising to 96.5% (91-100) at 6 years post HWBI. Baseline cosmesis after wound healing prior to HWBI was scored as excellent/good in 86% of cases by subjective (patient) and in 74% by objective (doctor) assessment with no impairment thereafter. CONCLUSIONS Acute and late treatment tolerance of a combined Boost-IOERT/HWBI regimen is excellent in short/mid-term assessment. Postoperative cosmetic appearance is not impaired after 3 years FUP.
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Affiliation(s)
- Gerd Fastner
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria.
| | - Roland Reitsamer
- Department of Gynecology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Bartosz Urbański
- Department of Radiotherapy and Gynecological Oncology, Greater Poland Cancer Centre, Poznań, Poland
| | - Peter Kopp
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Dawid Murawa
- Clinic of General Surgery and Surgical Oncology, Faculty of Medicine and Health Sciences University, Zielona Gora, Poland
| | - Beata Adamczyk
- Department of Surgical Oncology, Greater Poland Cancer Centre, Poznań, Poland
| | | | - Piotr Milecki
- Department of Radiotherapy Greater Poland Cancer Center and Chair of Electroradiology Poznan University of Medical Sciences, Poznań, Poland
| | - Eva Hager
- Department of Radiotherapy/Radiooncology, Klagenfurt, Austria
| | - Juliann Reiland
- Avera McKennan Hospitals and University Health System, Avera Medical Group, Comprehensive Breast Care, Sioux Falls, United States
| | | | - Christiane Matuschek
- Medical Faculty, Department of Radiation Oncology, Heinrich Heine University, Düsseldorf, Germany
| | - Wilfried Budach
- Medical Faculty, Department of Radiation Oncology, Heinrich Heine University, Düsseldorf, Germany
| | - Kerri Nowell
- Department of General Surgery, UnityPoint Health-St.Lukes Hospital, Cedar Rapids, United States
| | - Claudia Schumacher
- Breast Center/Department of Senology, St.-Elisabeth Hospital Cologne-Hohenlind, Germany
| | - Angelika Ricke
- Radiation Institute-CDT-center for Diagnostic and Therapy GmbH, Cologne, Germany
| | - Vincenzo Fusco
- Radioterapia, IRCCS-CROB Reference Cancer Center Basilicata, Rionero in Vulture, Italy
| | - Cristiana Vidali
- Department of Radiation Oncology, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Italy
| | - Marina Alessandro
- Division of Radiation Oncology, Ospedale di Città di Castello, USL UMBRIA 1, Città di Castello, Italy
| | | | - Ingrid Ziegler
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Christoph Fussl
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Franz Zehentmayr
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Brane Grambozov
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Andreas Sir
- Department of Gynecology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Wolfgang Hitzl
- Research Office - Biostatistics, Paracelsus Medical University Salzburg, Austria; Department of Ophthalmology and Optometry, Paracelsus Medical University Salzburg, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | | | - Felix Sedlmayer
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
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Abstract
This chapter introduces this topic for the whole volume. It is not a review, rather it presents the basics, the key considerations and forward references to the other chapters. This starts by setting the scene of principles and overall strategy, moves onto planning an experiment including its feasibility and then outlines practicalities with options for the experiment. The crystal structure that results will lead to publication and associated with it, Protein Data Bank deposition.
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Jiang M, Zheng X, Chen Y. Enhancement of denitrification performance with reduction of nitrite accumulation and N 2O emission by Shewanella oneidensis MR-1 in microbial denitrifying process. Water Res 2020; 169:115242. [PMID: 31706124 DOI: 10.1016/j.watres.2019.115242] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 08/31/2019] [Accepted: 10/26/2019] [Indexed: 06/10/2023]
Abstract
Bio-denitrification (i.e., microbial reduction of nitrate to gaseous nitrogen) is usually reported to be affected by operating and environmental parameters, such as carbon source type, pH value, and temperature. In this paper, the enhancement of denitrification performance with the elimination of nitrite accumulation and nitrous oxide emission by Shewanella oneidensis MR-1 were investigated and the mechanisms were explored. It was found that S. oneidensis MR-1 itself had marginal nitrate removal capacity, but its presence in the denitrification system of a well-studied denitrifier (Paracoccus denitrificans) obviously enhanced nitrate removal efficiency (from 65.3% to 97.8%) and reduced nitrite accumulation (0.67 against none-detectable) and N2O generation (from 8.87 μm/mM-TN to none-detectable). The mechanism study showed that S. oneidensis MR-1 promoted electrons transfer activity via the formation of nanotube between cells, which resulted in the increase of denitrification enzymes activity, carbon source metabolism, ATP level and cell viability. As the generation, transfer and consumption of electrons were enhanced by S. oneidensis MR-1, the improvement of denitrification performance with reduction of nitrite accumulation and N2O emission was therefore achieved. Finally, the performance of denitrification enhanced by S. oneidensis MR-1 was testified by laboratory groundwater treatment experiment. This study suggested the potential role of S. oneidensis MR-1 in accelerating nitrate bio-transformation in nitrogen geochemical cycle and increasing bio-treatment of nitrate contamination with negligible harmful intermediates (nitrite and N2O) accumulation.
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Affiliation(s)
- Meng Jiang
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Xiong Zheng
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Yinguang Chen
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China.
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Shahbazian H, Bakhshali R, Shamsi A, Bagheri A. Dosimetric analysis of breast cancer tumor bed boost: An interstitial brachytherapy vs. external beam radiation therapy comparison for deeply seated tumors. Brachytherapy 2019; 19:264-274. [PMID: 31787575 DOI: 10.1016/j.brachy.2019.10.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/23/2019] [Accepted: 10/24/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE To dosimetrically compare interstitial brachytherapy (MIBT) vs. EBRT (3DCRT and high-energy electron beams) for deep-seated tumor bed boosts (depth ≥4 cm) in early-stage breast cancer. METHODS AND MATERIALS Planning CTs of fifteen left-side breast cancer patients previously treated with MIBT boost chosen for this study. MIBT, 3DCRT (three-field technique), and enface high-energy electron (15-18 MeV) plans retrospectively generated on these images. To minimize intrapatient target contour inconsistency, due to a technical limitation for transferring identical contours from brachytherapy to EBRT planning system, spherical volumes delineated as hypothetical CTVs (CTV-H) (depth ≥4 cm with considering the geometry of the brachytherapy implant) instead of original lumpectomy cavities (which had irregular contours). In EBRT, PTV-H=CTV-H+5 mm. To account for beam penumbra, additional PTV-H to beam-edge margins added (3DCRT = 5 mm; electron = 10 mm). Included organs at risk (OARs) were ipsilateral breast, skin, ribs, lung, and heart. Prescribed dose-fractionations were 12 Gy/3fractions (MIBT) and 16 Gy/8fractions (EBRT) (BED = 24 Gy, breast cancer Alpha/Beta = 4 Gy). Biologically equivalent DVH parameters for all techniques compared. RESULTS Mean CTV-H depth was 6 cm. Normal breast V25%-V100%; skin V10%-V90%; rib V25%-V75%; lung V5%-V25%; heart V10%; mean lung dose; ribs/lung Dmax were lower in MIBT vs. 3CDRT. MIBT reduced breast V25%-V125%; skin V25%-V125%; rib V25%-V75% and V100%; lung V25%-V90%; heart V10%-V50%; skin/ribs/lung Dmax compared to electrons. In contrast, breast V125%-V250% and V175%-V250% were increased in MIBT vs. 3DCRT and electron plans, respectively. Electron plans had the minimum mean heart dose. CONCLUSIONS From a dosimetric point of view, in deeply-seated lumpectomy beds, MIBT boost better protects OARs from exposure to medium and high doses of radiation compared to 3DCRT and high energy electron beams (except more ipsilateral breast hot spots).
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Affiliation(s)
- Hodjatollah Shahbazian
- Department of Radiation Oncology, Golestan Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Roksana Bakhshali
- Department of Radiation Oncology, Golestan Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Azin Shamsi
- Department of Radiation Oncology, Golestan Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ali Bagheri
- Interventional Radiotherapy Ward, Department of Radiation Oncology, Golestan Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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Richmond N, Allen V, Wyatt J, Codling R. Evaluation of the RayStation electron Monte Carlo dose calculation algorithm. Med Dosim 2019; 45:159-167. [PMID: 31629601 DOI: 10.1016/j.meddos.2019.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/25/2019] [Accepted: 09/14/2019] [Indexed: 11/26/2022]
Abstract
The aim of this work was to evaluate the accuracy of the RayStation treatment planning system electron Monte Carlo algorithm against measured data for a range of clinically relevant scenarios. This was done by comparing measured percentage depth dose data (PDD) in water, profiles at oblique incidence and with heterogeneities in the beam path, and output factor data and that generated using the RayStation treatment planning system Monte Carlo VMC++ based calculation algorithm. While electron treatments are widely employed in the radiotherapy setting accurate modelling is challenging (TPS) in the presence of patient being both heterogeneous and nonrectangular. Watertank-based measurements were made on a Varian TrueBeam linear accelerator covering electron beam energies 6 to 18 MeV. These included both normal and oblique incidence, heterogeneous geometries, and irregular shaped cut-outs. The measured geometries were replicated in RayStation and the Monte Carlo dose calculation engine used to generate dosimetric data for comparison against measurement in what were considered clinically relevant settings. Water-based PDDs and profile comparisons showed excellent agreement for all electron beam energies. Profiles measured with oblique beam incidence demonstrated acceptable agreement to the treatment planning system calculations although the correspondence worsened as the angle increased with the planning system overestimating the dose in the shoulder region. Profile measurements under inhomogeneities were generally good. The planning system had a tendency to overestimate dose under the heterogeneity and also demonstrated a broader penumbra than measurement. Of the 170 different output factors calculated in RayStation over the range of electron energies commissioned, 141 were within ± 3% of measured values and 164 within ± 5%. Four of the 6 comparisons beyond 5% were at 18 MeV and all had a cut-out edge within 3 cm of the beam central axis/measurement point. The RayStation implementation of a VMC++ electron Monte Carlo dose calculation algorithm shows good agreement with measured data for a range of scenarios studied and represented sufficient accuracy for clinical use.
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Affiliation(s)
- Neil Richmond
- Department of Radiotherapy Physics, Northern Centre for Cancer Care, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK.
| | - Vincent Allen
- Department of Radiotherapy Physics, Northern Centre for Cancer Care, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK
| | - Jonathan Wyatt
- Department of Radiotherapy Physics, Northern Centre for Cancer Care, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK
| | - Richard Codling
- Department of Radiotherapy Physics, Northern Centre for Cancer Care, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK
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Ade N, van Eeden D, du Plessis FCP. Characterization of Nylon-12 as a water-equivalent solid phantom material for dosimetric measurements in therapeutic photon and electron beams. Appl Radiat Isot 2019; 155:108919. [PMID: 31622845 DOI: 10.1016/j.apradiso.2019.108919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 08/26/2019] [Accepted: 10/02/2019] [Indexed: 10/25/2022]
Abstract
The tissue- or water-equivalence of dosimetry phantoms used as substitutes for water is essential for absorbed dose measurements in radiotherapy. At our institution, a heterogeneous pelvic phantom that consists of stacked Nylon-12 layers has recently been manufactured for Gafchromic film dosimetry. However, data on the use of Nylon as tissue-mimicking media for dosimetric applications are scarce. This study characterizes the water-equivalence of Nylon-12 for dosimetric measurements in therapeutic photon and electron beams. Employing an Elekta Synergy and SL25 linear accelerator (Linac), photon beam transmission measurements for 6 MV and 15 MV, acquired in narrow beam geometry with a 0.6 cm3 Farmer-type ion chamber showed that the mass attenuation coefficient μm of Nylon-12 agrees with the values of water, water-equivalent RW3 and Perspex phantom materials within 3%. For 6 MV, the μm values were 0.0477 ± 0.002 cm2/g, 0.0490 ± 0.003 cm2/g, 0.0482 ± 0.001 cm2/g and 0.0479 ± 0.002cm2/g for Nylon-12, water, RW3, and Perspex, respectively. Differences within 2% were attained between depth dose data measured in Nylon-12 slabs with Gafchromic EBT3 films and in water with a Roos ion chamber for 10 × 10 cm2 6, 12 and 20 MeV electron beams produced by the Elekta Synergy and SL25 Linacs. Also, a good agreement within 2% was obtained between percent depth doses computed by DOSXYZnrc Monte Carlo simulations in water, Nylon-12 and RW3 materials for photon spectra between 250 kV and 15 MV. The discrepancies between the ratios of average, restricted stopping powers of Nylon to air and water to air for photon spectra ranging from 2 to 45 MV are typically within 1% signifying that Nylon and water have equivalent stopping power characteristics. This study highlights that Nylon-12 can be used as a tissue-mimicking phantom material for dosimetric measurements in clinical megavoltage photon and electron beams as it exhibits good water-equivalence.
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Affiliation(s)
- Nicholas Ade
- Medical Physics Department, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa.
| | - D van Eeden
- Medical Physics Department, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
| | - F C P du Plessis
- Medical Physics Department, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
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Sanchis E, Casans S, García-Gil R, Martos J, Sanchis-Sánchez E, Pérez-Calatayud I, José Pérez-Calatayud M, Pérez-Calatayud J. Improving bleeding detector features for electron intraoperative radiotherapy. Phys Med 2019; 65:150-156. [PMID: 31473502 DOI: 10.1016/j.ejmp.2019.08.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/22/2019] [Accepted: 08/23/2019] [Indexed: 10/26/2022] Open
Abstract
PURPOSE The aim of this work is to improve the potential bleeding detection during intraoperative radiotherapy with linac polymethyl methacrylate applicators (PMMA), based on one previously developed. The improvements carried out have been focused on: i) minimizing the impact of the detector on the visual through the plastic applicators and ii) avoiding the asymmetry in the detection capability when the applicator is tilted. METHODS Simulations have been made to select the geometry that provides a reduced visual impact on the applicator as well as allowing an independent response with the tilting angle of the applicator. A low-noise circuit for signal conditioning has been developed. Measurements have been made on three setups: 10 cm, 7 cm and 4 cm applicator diameters, 0° and 45° tilted. RESULTS The detector has a visibility through the applicator greater than 50%. Due to the geometry, optimal detection is ensured regardless of its orientation when the applicator is tilted. It is possible to detect the presence of fluid well below the typical perturbing fluid depth established by the clinic (1-1.5 cm). CONCLUSIONS The detector can distinguish the presence of around 0.5 cm of fluid depth while showing a high visual field through the PMMA applicators and providing a measure that does not depend on the detector orientation when the applicator is tilted. The prototype is ready for its industrialization by embedding it into the applicator for clinical use. The detector would have a significant impact on both the quality assurance and the outcome of the treatment.
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Affiliation(s)
- Enrique Sanchis
- Department of Electronic Engineering, University of Valencia, E-46100, Spain; IRIMED Joint Research Unit (IIS La Fe - UV), Valencia, Spain.
| | - Silvia Casans
- Department of Electronic Engineering, University of Valencia, E-46100, Spain
| | - Rafael García-Gil
- Department of Electronic Engineering, University of Valencia, E-46100, Spain
| | - Julio Martos
- Department of Electronic Engineering, University of Valencia, E-46100, Spain
| | - Enrique Sanchis-Sánchez
- Department of Physical Therapy, University of Valencia, E-46010, Spain; IRIMED Joint Research Unit (IIS La Fe - UV), Valencia, Spain
| | | | | | - José Pérez-Calatayud
- Department of Radiation Oncology, La Fe Polytechnic and University Hospital, Valencia E-46026, Spain; IRIMED Joint Research Unit (IIS La Fe - UV), Valencia, Spain
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Sanchis E, Casans S, Felici G, García-Gil R, Sanchis-Sánchez E, Pérez-Calatayud I, Pérez-Calatayud MJ, Pérez-Calatayud J. Detector for monitoring potential bleeding during electron intraoperative radiotherapy. Phys Med 2019; 57:95-9. [PMID: 30738538 DOI: 10.1016/j.ejmp.2018.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/30/2018] [Accepted: 12/15/2018] [Indexed: 11/22/2022] Open
Abstract
PURPOSE The aim of this work is to develop a bleeding detector integrated into the acrylic circular applicators for specific mobile linacs. Thus, a bleeding detector has been developed based on a capacitive sensor to be used with plastic applicators, as in the case of LIAC HWL from Sordina IORT Technologies SpA. According to the clinical impact, we have selected 0.5 cm as the minimum depth of fluid that should be detected. METHODS An experiment was developed using water-simulating blood. Two setups were considered: non-beveled applicators with 7 cm and 10 cm diameter. Measurements were done for applicators 0° and 45° tilted, both with respect to the horizontal surface, in order to mimic the worst clinical scenario according to the irradiation gantry and applicator bevel angle. The behavior of the detector under irradiation was analyzed and the impact of the stray radiation on the detector was also evaluated. RESULTS The detector was able to distinguish the presence of liquid at a minimum height of 0.5 cm. A linear behavior was obtained for both setups. We have also verified that the LIAC HWL radiation does not affect the measurements nor does the detector interfere with the stray radiation. The bleeding detector is a quasi-digital capacitive sensor with low-cost, high linearity, and easy to install. CONCLUSIONS With this detector it is possible to perform a continuous monitoring of the liquid measurements even during the irradiation phase. Thus, it can operate not only as a pre-treatment detector but also as a continuous one.
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Craft DF, Balter P, Woodward W, Kry SF, Salehpour M, Ger R, Peters M, Baltz G, Traneus E, Howell RM. Design, fabrication, and validation of patient-specific electron tissue compensators for postmastectomy radiation therapy. Phys Imaging Radiat Oncol 2018; 8:38-43. [PMID: 33458415 PMCID: PMC7807570 DOI: 10.1016/j.phro.2018.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 11/09/2018] [Accepted: 11/13/2018] [Indexed: 11/17/2022] Open
Abstract
Background and purpose Postmastectomy radiotherapy (PMRT) is complex to plan and deliver, but could be improved with 3D-printed, patient-specific electron tissue compensators. The purposes of this study were to develop an algorithm to design patient-specific compensators that achieve clinical goals, to 3D-print the planned compensators, and validate calculated dose distributions with film and thermoluminescent dosimeter (TLD) measurements in 3D-printed phantoms of PMRT patients. Materials and methods An iterative algorithm was developed to design compensators corresponding to single-field, single-energy electron plans for PMRT patients. The 3D-printable compensators were designed to fit into the electron aperture, with cerrobend poured around it. For a sample of eight patients, calculated dose distributions for compensator plans were compared with patients’ (multi-field, multi-energy) clinical treatment plans. For all patients, dosimetric parameters were compared including clinical target volume (CTV), lung, and heart metrics. For validation, compensators were fabricated and irradiated for a set of six 3D-printed patient-specific phantoms. Dose distributions in the phantoms were measured with TLD and film. These measurements were compared with the treatment planning system calculated dose distributions. Results The compensator treatment plans achieved superior CTV coverage (97% vs 89% of the CTV receiving the prescription dose, p < 0.0025), and similar heart and lung doses (p > 0.35) to the conventional treatment plans. Average differences between calculated and measured TLD values were 2%, and average film profile differences were <2 mm. Conclusions We developed a new compensator based treatment methodology for PMRT and demonstrated its validity and superiority to conventional multi-field plans through end-to-end testing.
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Affiliation(s)
- Daniel F. Craft
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
- Corresponding author at: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 94, Houston, TX 77030, USA.
| | - Peter Balter
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Wendy Woodward
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Stephen F. Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Mohammad Salehpour
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Rachel Ger
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Mary Peters
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Garrett Baltz
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
| | - Erik Traneus
- RaySearch Laboratories AB, Stockholm 111 34, Sweden
| | - Rebecca M. Howell
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030, USA
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Mei K, Ehn S, Oechsner M, Kopp FK, Pfeiffer D, Fingerle AA, Pfeiffer F, Combs SE, Wilkens JJ, Rummeny EJ, Noël PB. Dual-layer spectral computed tomography: measuring relative electron density. Eur Radiol Exp 2018; 2:20. [PMID: 30175319 PMCID: PMC6103960 DOI: 10.1186/s41747-018-0051-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 05/25/2018] [Indexed: 11/22/2022] Open
Abstract
Background X-ray and particle radiation therapy planning requires accurate estimation of local electron density within the patient body to calculate dose delivery to tumour regions. We evaluate the feasibility and accuracy of electron density measurement using dual-layer computed tomography (DLCT), a recently introduced dual-energy CT technique. Methods Two calibration phantoms were scanned with DLCT and virtual monoenergetic images (VMIs) at 50 keV and 200 keV were generated. We investigated two approaches to obtain relative electron densities from these VMIs: to fit an analytic interaction cross-sectional model and to empirically calibrate a conversion function with one of the phantoms. Knowledge of the emitted x-ray spectrum was not required for the presented work. Results The results from both methods were highly correlated to the nominal values (R > 0.999). Except for the water and lung inserts, the error was within 1.79% (average 1.53%) for the cross-sectional model and 1.61% (average 0.87%) for the calibrated conversion. Different radiation doses did not have a significant influence on the measurement (p = 0.348, 0.167), suggesting that the methods are reproducible. Further, we applied these methods to routine clinical data. Conclusions Our study shows a high validity of electron density estimation based on DLCT, which has potential to improve the procedure and accuracy of measuring electron density in clinical practice.
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Affiliation(s)
- Kai Mei
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Sebastian Ehn
- 2Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
| | - Markus Oechsner
- Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Felix K Kopp
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Daniela Pfeiffer
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,2Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
| | - Alexander A Fingerle
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Franz Pfeiffer
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,2Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
| | - Stephanie E Combs
- Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Jan J Wilkens
- Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Ernst J Rummeny
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Peter B Noël
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,2Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
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Kaiser J, Reitsamer R, Kopp P, Gaisberger C, Kopp M, Fischer T, Zehentmayr F, Sedlmayer F, Fastner G. Intraoperative Electron Radiotherapy (IOERT) in the Treatment of Primary Breast Cancer. Breast Care (Basel) 2018; 13:162-167. [PMID: 30069175 DOI: 10.1159/000489637] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
IOERT (intraoperative electron radiotherapy) in breast cancer is used either as a boost (10-12 Gy) followed by whole breast irradiation (WBI) or as full-dose partial breast irradiation (PBI, 20-24 Gy) during breast-conserving surgery. IOERT has the longest evidence of all IORT techniques. When administered as a boost, excellent low local recurrence rates were observed in long-term follow-up >5 years. Even in high-risk groups like triple-negative or locally advanced breast cancers, IOERT contributes to long-term local control rates of more than 90%. For selected low-risk groups, IOERT as PBI with 21 Gy seems to be a viable treatment alternative to standard WBI. IOERT has been shown to be advantageous for several reasons: Geographic misses are avoided due to direct visualization of the tumor bed; thus, a high single dose is delivered with utmost precision to small volumes, completely sparing the skin and ensuring good long-term cosmetic outcome. Furthermore, high single doses seem to induce biological mechanisms with verifiable antitumor capability in in-vitro cell-line studies. In addition, IOERT markedly shortens the overall treatment time both in combination with (now mostly hypofractionated) WBI or as a PBI in selected low-risk constellations.
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Affiliation(s)
- Julia Kaiser
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Roland Reitsamer
- Department of Gynecology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Peter Kopp
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Christoph Gaisberger
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Michael Kopp
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Thorsten Fischer
- Department of Gynecology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Franz Zehentmayr
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Felix Sedlmayer
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
| | - Gerd Fastner
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, University Hospital Salzburg, Landeskrankenhaus, Salzburg, Austria
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Wei TT, Mei LY. [Occupational health status of electronics manufacturing female employees in China]. Zhonghua Yu Fang Yi Xue Za Zhi 2018; 52:206-209. [PMID: 29429280 DOI: 10.3760/cma.j.issn.0253-9624.2018.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Electronics industry is a typical labor-intensive industry in China. There are a lot of female workers and various occupational hazard factors in the workplace. This article reviewed the characteristics of employment of women in electronics industry, occupational hazards of exposure, protective measures, occupational disease situation, influence of reproductive health and mental health, and occupational health management. Electronics female emplyees have the priority in reproductive health and mental health. Besides, this group has poor protective measures, occupational health management and policy should be taken to enhance the level of women health in electronics industry.
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Affiliation(s)
- T T Wei
- Hubei Provincial Center for Disease Control and Prevention, Wuhan 430079, China
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Archambault JP. Monte Carlo calculations of electrons impinging on a copper target: A comparison of EGSnrc, Geant4 and MCNP5. Appl Radiat Isot 2017; 132:129-134. [PMID: 29220726 DOI: 10.1016/j.apradiso.2017.11.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/29/2017] [Accepted: 11/15/2017] [Indexed: 10/18/2022]
Abstract
A simple geometry is used to compare several of the available Monte Carlo software codes for radiation transport. EGSnrc, Geant4 and MCNP5 are all used to calculate the photon fluence produced from electrons incident on a copper target. Four energies for the isotropic point source are chosen to simulate the average and maximum emission energies of 32P and 90Y: (0.7, 1.71)MeV and (0.93, 2.28)MeV, respectively. The energy deposition in the copper target, the electron current at the target and the computational efficiency are also calculated. EGSnrc is found to be the only self-consistent code when comparing results calculated using the default transport parameters of the condensed history mode with those calculated in the single scattering mode.
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Vyšín L, Tomanová K, Pavelková T, Wagner R, Davídková M, Múčka V, Čuba V, Juha L. Degradation of phospholipids under different types of irradiation and varying oxygen saturation. Radiat Environ Biophys 2017; 56:241-247. [PMID: 28500389 DOI: 10.1007/s00411-017-0693-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 05/04/2017] [Indexed: 06/07/2023]
Abstract
The effects of different types of radiation on the formation of peroxide forms of 2-dioleoyl-sn-glycero-3-phosphocholine were studied under various conditions. For the irradiation, an aqueous solution of small unilamellar vesicles was prepared. Variations in parameters such as the dose rate and molecular oxygen saturation levels were evaluated. Our study suggests that the mechanism of the peroxides formation process remains unchanged under irradiation by accelerated electrons, gamma and accelerated protons. The values of radiation chemical yields of the peroxidic form depend on the type of radiation, dose rate, and the saturation of molecular oxygen. The level of oxygen saturation strongly affects the values of radiation chemical yields as well, as the dissolved oxygen is an important agent participating in peroxidation and it is a source of free radicals during the radiolysis. The values of radiation chemical yields strongly suggest that the mechanism of radiation-induced peroxidation of phosphatidylcholines does not proceed via chain reaction.
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Affiliation(s)
- Luděk Vyšín
- Institute of Physics of the CAS, Na Slovance 1999/2, 182 21, Prague, Czech Republic.
- FNSPE, Czech Technical University in Prague, Břehová 7, 115 19, Prague, Czech Republic.
| | - Kateřina Tomanová
- FNSPE, Czech Technical University in Prague, Břehová 7, 115 19, Prague, Czech Republic
| | - Tereza Pavelková
- FNSPE, Czech Technical University in Prague, Břehová 7, 115 19, Prague, Czech Republic
| | - Richard Wagner
- Nuclear Physics Institute of the CAS, Husinec-Řež 130, 250 68, Řež, Czech Republic
| | - Marie Davídková
- Nuclear Physics Institute of the CAS, Husinec-Řež 130, 250 68, Řež, Czech Republic
| | - Viliam Múčka
- FNSPE, Czech Technical University in Prague, Břehová 7, 115 19, Prague, Czech Republic
| | - Václav Čuba
- FNSPE, Czech Technical University in Prague, Břehová 7, 115 19, Prague, Czech Republic
| | - Libor Juha
- Institute of Physics of the CAS, Na Slovance 1999/2, 182 21, Prague, Czech Republic
- Institute of Plasma Physics of the CAS, Za Slovankou 3, 182 00, Prague, Czech Republic
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Loganadane G, Xi Z, Xu HP, Grellier Adedjouma N, Bazire L, Fourquet A, Kirova YM. Patterns of loco regional failure in women with breast cancer treated by Postmastectomy Conformal Electron Beam Radiation Therapy (PMERT): Large scale single center experience. Clin Transl Radiat Oncol 2017; 4:46-50. [PMID: 29594207 PMCID: PMC5833921 DOI: 10.1016/j.ctro.2017.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/24/2017] [Accepted: 03/24/2017] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate loco regional control and describe the patterns of loco regional failure in women with breast cancer irradiated by a previously described post-mastectomy highly conformal electron beam radiotherapy technique. Materials and methods We included all women irradiated by PMERT for non-metastatic breast cancer (BC) between 2007 and 2011 in our department. All cases of bilateral BC were excluded. All patients who experienced loco regional recurrence have been studied. Mapping patterns of regional recurrences was also performed and compared with the ESTRO and RTOG Guidelines of volume definition and delineation guidelines. Results Among the 796 women included, 10.1% were triple-negative (TN) and 18.8% were HER2-positive and 24.6% of them had received neoadjuvant chemotherapy (CT). Internal mammary chain (IMC), supraclavicular (Level IV), infraclavicular (Levels III and II) and axillary LN (Level I) were treated in 85.6%, 88.3%, 77.9% and 14.9% of cases, respectively. With a median follow-up of 64 months (range: 6-102), 5-year locoregional (RFS and OS were 90% (95% CI: 88.1-92.4) and 90.9% (95% CI: 88.9-93), respectively. Twenty-three patients (2.9%) presented locoregional recurrences. Most of them presented aggressive biological features with grade III tumors in 17 patients (74%) with high mitotic index in 16 cases (70%) and triple negative tumors in 12 (52%). Lymphovascular invasion (LVI) was observed in 11 cases (48%). In 14 cases the locoregional recurrences were diagnosed at the same time as the metastatic disease whereas 4 patients presented distant metastases secondarily. Local (Chest wall) recurrences occurred in 13 cases (56%) with the coverage by the isodose of 47.5 Gy (isodose 95%). Fifteen regional recurrences (lymph nodes) were observed in 13 patients. Only 3 regional recurrences occurred within irradiated volumes and 12 regional recurrences occurred outside irradiated areas. Conclusion In presented series, the local recurrences were related mostly to the tumor biological aggressivity and radio resistance. Small number was caused by geographical miss. Further follow-up and careful registration of the recurrences is needed to improve their understanding.
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Affiliation(s)
| | - Zhen Xi
- Department of Radiation Oncology, Institut Curie, Paris, France
| | - Hao Ping Xu
- Department of Radiation Oncology, Institut Curie, Paris, France
| | | | - Louis Bazire
- Department of Radiation Oncology, Institut Curie, Paris, France
| | - Alain Fourquet
- Department of Radiation Oncology, Institut Curie, Paris, France
| | - Youlia M Kirova
- Department of Radiation Oncology, Institut Curie, Paris, France
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Sedlmayer F, Reitsamer R, Wenz F, Sperk E, Fussl C, Kaiser J, Ziegler I, Zehentmayr F, Deutschmann H, Kopp P, Fastner G. Intraoperative radiotherapy (IORT) as boost in breast cancer. Radiat Oncol 2017; 12:23. [PMID: 28103903 PMCID: PMC5244574 DOI: 10.1186/s13014-016-0749-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 12/21/2016] [Indexed: 01/15/2023] Open
Abstract
The term IORT (intraoperative radiotherapy) is currently used for various techniques that show huge differences in dose delivery and coverage of the tissue at risk. The largest evidence for boost IORT preceding whole breast irradiation (WBI) originates from intraoperative electron treatments (IOERT) with single doses around 10 Gy. At median follow-up periods at 6 years, outstandingly low local recurrence rates of less than 1% are observed. Higher local relapse rates were described for G3 tumors and triple negative breast cancers as well as for IORT following primary systemic treatment for locally advanced tumors. Even there, long term (>5y) local tumor control rates mostly beyond 95% were maintained. Compared to other boost methods, an intraoperative treatment has evident advantages in terms of precision (by avoiding a “spatial and/or temporal miss”), cosmetic outcome and patient comfort. Direct visualisation of a tumor bed during surgery guarantees for an accurate dose delivery, which has additionally gained importance in times of primary reconstruction techniques after lumpectomy, since IORT is performed before breast tissue including parts of the tumor bed is mobilized for plastic purposes. As a consequence of direct tissue exposure without distension by hematoma/seroma, IORT allows for small treatment volumes and complete skin sparing, both having a positive effect on late tissue tolerance and, hence, cosmetic appearance. Boost IORT marginally prolongs the surgical procedure, while significantly shortening postoperative radiotherapy. Its combination with external beam radiotherapy to the whole breast (WBI) is currently tested in two multicentric prospective trials: as kV-IORT in the multicentric TARGIT-B (oost) study, and as IOERT in the HIOB trial (3 weeks hypofractionated WBI preceded by IORT electron boost).
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Affiliation(s)
- Felix Sedlmayer
- Department of Radiotherapy and Radio-Oncology, LKH Salzburg, Paracelsus Medical University Clinics, Muellner Hauptstrasse 48, 5020, Salzburg, Austria. .,Institute of Research and Development of Advanced Radiation Technologies (radART), Paracelsus Medical University, 5020, Salzburg, Austria.
| | - Roland Reitsamer
- Department of Special Gynecology and Breast Center, LKH Salzburg, Paracelsus Medical University Clinics, 5020, Salzburg, Austria
| | - Frederik Wenz
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
| | - Elena Sperk
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
| | - Christoph Fussl
- Department of Radiotherapy and Radio-Oncology, LKH Salzburg, Paracelsus Medical University Clinics, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Julia Kaiser
- Department of Radiotherapy and Radio-Oncology, LKH Salzburg, Paracelsus Medical University Clinics, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Ingrid Ziegler
- Department of Radiotherapy and Radio-Oncology, LKH Salzburg, Paracelsus Medical University Clinics, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Franz Zehentmayr
- Department of Radiotherapy and Radio-Oncology, LKH Salzburg, Paracelsus Medical University Clinics, Muellner Hauptstrasse 48, 5020, Salzburg, Austria.,Institute of Research and Development of Advanced Radiation Technologies (radART), Paracelsus Medical University, 5020, Salzburg, Austria
| | - Heinz Deutschmann
- Department of Radiotherapy and Radio-Oncology, LKH Salzburg, Paracelsus Medical University Clinics, Muellner Hauptstrasse 48, 5020, Salzburg, Austria.,Institute of Research and Development of Advanced Radiation Technologies (radART), Paracelsus Medical University, 5020, Salzburg, Austria
| | - Peter Kopp
- Department of Radiotherapy and Radio-Oncology, LKH Salzburg, Paracelsus Medical University Clinics, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Gerd Fastner
- Department of Radiotherapy and Radio-Oncology, LKH Salzburg, Paracelsus Medical University Clinics, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
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Abstract
Scanning electron microscopes allow us to reach magnifications of 20-130,000× and resolve compositional and topographical images with intense detail. These images are created by bombarding a sample with electrons in a focused manner to generate a black and white image from the electrons that bounce off of the sample. The electrons are detected using positively charged detectors. Scanning electron microscopy permits three-dimensional imaging of desiccated specimens or wet cells and tissues by using variable pressure chambers. SEM ultrastructural analysis and intracellular imaging supplement light microscopy for molecular profiling of prokaryotes, plants, and mammals. This chapter demonstrates how to prepare and image samples that are (a) desiccated and conductive, (b) desiccated and nonconductive but coated with an electron conductive film using a gold sputter coater, and
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Affiliation(s)
- Jenny Ngoc Tran Nguyen
- Northern Virginia Community College, Manassas Campus, 6901 Sudley Road, Manassas, VA, 20109, USA.
| | - Amanda M Harbison
- Northern Virginia Community College, Manassas Campus, 6901 Sudley Road, Manassas, VA, 20109, USA
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40
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Brualla L, Rodriguez M, Lallena AM. Monte Carlo systems used for treatment planning and dose verification. Strahlenther Onkol 2016; 193:243-259. [PMID: 27888282 DOI: 10.1007/s00066-016-1075-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 10/25/2016] [Indexed: 11/28/2022]
Abstract
General-purpose radiation transport Monte Carlo codes have been used for estimation of the absorbed dose distribution in external photon and electron beam radiotherapy patients since several decades. Results obtained with these codes are usually more accurate than those provided by treatment planning systems based on non-stochastic methods. Traditionally, absorbed dose computations based on general-purpose Monte Carlo codes have been used only for research, owing to the difficulties associated with setting up a simulation and the long computation time required. To take advantage of radiation transport Monte Carlo codes applied to routine clinical practice, researchers and private companies have developed treatment planning and dose verification systems that are partly or fully based on fast Monte Carlo algorithms. This review presents a comprehensive list of the currently existing Monte Carlo systems that can be used to calculate or verify an external photon and electron beam radiotherapy treatment plan. Particular attention is given to those systems that are distributed, either freely or commercially, and that do not require programming tasks from the end user. These systems are compared in terms of features and the simulation time required to compute a set of benchmark calculations.
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Affiliation(s)
- Lorenzo Brualla
- NCTeam, Strahlenklinik, Universitätsklinikum Essen, Hufelandstraße 55, D-45122, Essen, Germany.
| | | | - Antonio M Lallena
- Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, E-18071, Granada, Spain
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Li M, Su Y, Chen Y, Wan R, Zheng X, Liu K. The effects of fulvic acid on microbial denitrification: promotion of NADH generation, electron transfer, and consumption. Appl Microbiol Biotechnol 2016; 100:5607-18. [PMID: 26894403 DOI: 10.1007/s00253-016-7383-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 02/01/2016] [Accepted: 02/03/2016] [Indexed: 12/16/2022]
Abstract
The heterotrophic denitrification requires the participation of electrons which are derived from direct electron donor (usually nicotinamide adenine dinucleotide (NADH)), and the electrons are transferred via electron transport system in denitrifiers and then consumed by denitrifying enzymes. Despite the reported electron transfer ability of humic substances (HS), the influences of fulvic acid (FA), an ubiquitous major component of HS, on promoting NADH generation, electron transfer, and consumption in denitrification process have never been reported. The presence of FA, compared with the control, was found not only significantly improved the total nitrogen (TN) removal efficiency (99.9 % versus 74.8 %) but remarkably reduced the nitrite accumulation (0.2 against 43.8 mg/L) and N2O emission (0.003 against 0.240 mg nitrogen/mg TN removed). The mechanisms study showed that FA increased the metabolism of carbon source via glycolysis and tricarboxylic acid (TCA) cycle pathways to produce more available NADH. FA also facilitated the electron transfer activities from NADH to denitrifying enzymes via complex I and complex III in electron transport system, which improved the reduction of nitrate and accelerated the transformations of nitrite and N2O, and lower nitrite and N2O accumulations were therefore observed. In addition, the consumption of electrons in denitrification was enhanced due to FA stimulating the synthesis and the catalytic activity of key denitrifying enzymes, especially nitrite reductase and N2O reductase. It will provide an important new insight into the potential effect of FA on microbial denitrification metabolism process and even nitrogen cycle in nature niches.
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Affiliation(s)
- Mu Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Yinglong Su
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Yinguang Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China.
| | - Rui Wan
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Xiong Zheng
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Kun Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
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42
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Kairn T, Aland T, Crowe SB, Trapp JV. Use of electronic portal imaging devices for electron treatment verification. Australas Phys Eng Sci Med 2016; 39:199-209. [PMID: 26581763 DOI: 10.1007/s13246-015-0401-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 11/04/2015] [Indexed: 11/27/2022]
Abstract
This study aims to help broaden the use of electronic portal imaging devices (EPIDs) for pre-treatment patient positioning verification, from photon-beam radiotherapy to photon- and electron-beam radiotherapy, by proposing and testing a method for acquiring clinically-useful EPID images of patient anatomy using electron beams, with a view to enabling and encouraging further research in this area. EPID images used in this study were acquired using all available beams from a linac configured to deliver electron beams with nominal energies of 6, 9, 12, 16 and 20 MeV, as well as photon beams with nominal energies of 6 and 10 MV. A widely-available heterogeneous, approximately-humanoid, thorax phantom was used, to provide an indication of the contrast and noise produced when imaging different types of tissue with comparatively realistic thicknesses. The acquired images were automatically calibrated, corrected for the effects of variations in the sensitivity of individual photodiodes, using a flood field image. For electron beam imaging, flood field EPID calibration images were acquired with and without the placement of blocks of water-equivalent plastic (with thicknesses approximately equal to the practical range of electrons in the plastic) placed upstream of the EPID, to filter out the primary electron beam, leaving only the bremsstrahlung photon signal. While the electron beam images acquired using a standard (unfiltered) flood field calibration were observed to be noisy and difficult to interpret, the electron beam images acquired using the filtered flood field calibration showed tissues and bony anatomy with levels of contrast and noise that were similar to the contrast and noise levels seen in the clinically acceptable photon beam EPID images. The best electron beam imaging results (highest contrast, signal-to-noise and contrast-to-noise ratios) were achieved when the images were acquired using the higher energy electron beams (16 and 20 MeV) when the EPID was calibrated using an intermediate (12 MeV) electron beam energy. These results demonstrate the feasibility of acquiring clinically-useful EPID images of patient anatomy using electron beams and suggest important avenues for future investigation, thus enabling and encouraging further research in this area. There is manifest potential for the EPID imaging method proposed in this work to lead to the clinical use of electron beam imaging for geometric verification of electron treatments in the future.
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Fastner G, Hauser-Kronberger C, Moder A, Reitsamer R, Zehentmayr F, Kopp P, Fussl C, Fischer T, Deutschmann H, Sedlmayer F. Survival and local control rates of triple-negative breast cancer patients treated with boost-IOERT during breast-conserving surgery. Strahlenther Onkol 2015; 192:1-7. [PMID: 26403912 DOI: 10.1007/s00066-015-0895-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 08/27/2015] [Indexed: 11/26/2022]
Abstract
AIM The purpose of this work was to retrospectively evaluate survival and local control rates of triple-negative breast cancer subtypes classified as five marker negative (5NP) and core basal (CB), respectively, after breast-conserving surgery and intraoperative boost radiotherapy with electrons (IOERT) followed by whole breast irradiation. METHODS AND MATERIALS A total of 71 patients with triple-negative breast cancer were enrolled, who were treated with lumpectomy, axillary lymph node dissection, and IOERT with 9.6 Gy (median Dmax) followed by normofractionated whole breast irradiation to median total doses of 54 Gy. Chemotherapy was applied in a neoadjuvant (12 %), adjuvant (75 %), or combinational setting (7 %). RESULTS After a median follow-up of 97 months (range 4-170 months), 5 in-breast recurrences were detected (7.0 %). For all patients, 8-year actuarial rates for local control, metastases-free survival, disease-specific survival, and overall survival amounted to 89, 75, 80, and 69 %, respectively. All local recurrences occurred in grade 3 (G3) tumors irrespective of their specific immunohistochemical phenotype; thus, the local control rate for grades 1/2 (G1/2) was 100 % for both 5NP and CB, while for G3 it was 88 % for 5NP and 90 % for CB (p = 0.65 and 0.82, respectively, n.s.). For disease-specific survival, only the difference of the best-prognosis group 5-NP/G3 vs. the worst-prognosis cohort CB/G1/2 was statistically significant: 90 % vs. 54 % (p = 0.03). CONCLUSION Boost-IOERT provides acceptable long-term in-breast control in triple negative breast cancer. The best subgroup in terms of disease-specific survival was represented by 5NP in combination with tumor grading G3.
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MESH Headings
- Actuarial Analysis
- Biomarkers, Tumor/genetics
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/mortality
- Carcinoma, Ductal, Breast/pathology
- Carcinoma, Ductal, Breast/radiotherapy
- Carcinoma, Ductal, Breast/surgery
- Carcinoma, Lobular/genetics
- Carcinoma, Lobular/mortality
- Carcinoma, Lobular/pathology
- Carcinoma, Lobular/radiotherapy
- Carcinoma, Lobular/surgery
- Chemotherapy, Adjuvant
- Cohort Studies
- Combined Modality Therapy
- Dose Fractionation, Radiation
- Electrons/therapeutic use
- Female
- Follow-Up Studies
- Humans
- Intraoperative Period
- Lymph Node Excision
- Mastectomy, Segmental
- Neoplasm Staging
- Radiotherapy Dosage
- Survival Rate
- Triple Negative Breast Neoplasms/genetics
- Triple Negative Breast Neoplasms/mortality
- Triple Negative Breast Neoplasms/pathology
- Triple Negative Breast Neoplasms/radiotherapy
- Triple Negative Breast Neoplasms/surgery
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Affiliation(s)
- Gerd Fastner
- Department of Radiotherapy and Radio-Oncology, Landeskrankenhaus, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria.
| | | | - Angelika Moder
- Institute of Inborn Errors in Metabolism, Landeskrankenhaus, Paracelsus Medical University, Salzburg, Austria
| | - Roland Reitsamer
- Department of Special Gynecology, Landeskrankenhaus, Paracelsus Medical University, Salzburg, Austria
- Department of Gynecology, Landeskrankenhaus, Paracelsus Medical University, Salzburg, Austria
| | - Franz Zehentmayr
- Department of Radiotherapy and Radio-Oncology, Landeskrankenhaus, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Peter Kopp
- Department of Radiotherapy and Radio-Oncology, Landeskrankenhaus, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Christoph Fussl
- Department of Radiotherapy and Radio-Oncology, Landeskrankenhaus, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Thorsten Fischer
- Department of Special Gynecology, Landeskrankenhaus, Paracelsus Medical University, Salzburg, Austria
- Department of Gynecology, Landeskrankenhaus, Paracelsus Medical University, Salzburg, Austria
| | - Heinrich Deutschmann
- Department of Radiotherapy and Radio-Oncology, Landeskrankenhaus, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
- Institute for Research and Development of Advanced Radiation Technologies (radART), Paracelsus Medical University, Salzburg, Austria
| | - Felix Sedlmayer
- Department of Radiotherapy and Radio-Oncology, Landeskrankenhaus, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
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Sponseller P, Pelly N, Trister A, Ford E, Ermoian R. Radiation treatment for the right naris in a pediatric anesthesia patient using an adaptive oral airway technique. Med Dosim 2015; 40:201-4. [PMID: 25619555 DOI: 10.1016/j.meddos.2014.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 10/07/2014] [Accepted: 11/17/2014] [Indexed: 11/29/2022]
Abstract
Radiation therapy for pediatric patients often includes the use of intravenous anesthesia with supplemental oxygen delivered via the nasal cannula. Here, we describe the use of an adaptive anesthesia technique for electron irradiation of the right naris in a preschool-aged patient treated under anesthesia. The need for an intranasal bolus plug precluded the use of standard oxygen supplementation. This novel technique required the multidisciplinary expertise of anesthesiologists, radiation therapists, medical dosimetrists, medical physicists, and radiation oncologists to ensure a safe and reproducible treatment course.
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Affiliation(s)
| | - Nicole Pelly
- Department of Radiation Oncology, University of Washington, Seattle, WA
| | - Andrew Trister
- Department of Radiation Oncology, University of Washington, Seattle, WA
| | - Eric Ford
- Department of Radiation Oncology, University of Washington, Seattle, WA
| | - Ralph Ermoian
- Department of Radiation Oncology, University of Washington, Seattle, WA
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45
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Garnica-Garza HM. Influence of the electron energy and number of beams on the absorbed dose distributions in radiotherapy of deep seated targets. Appl Radiat Isot 2014; 94:101-108. [PMID: 25151497 DOI: 10.1016/j.apradiso.2014.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/17/2014] [Accepted: 07/28/2014] [Indexed: 10/24/2022]
Abstract
With the advent of compact laser-based electron accelerators, there has been some renewed interest on the use of such charged particles for radiotherapy purposes. Traditionally, electrons have been used for the treatment of fairly superficial lesions located at depths of no more than 4cm inside the patient, but lately it has been proposed that by using very high energy electrons, i.e. those with an energy in the order of 200-250MeV it should be possible to safely reach deeper targets. In this paper, we used a realistic patient model coupled with detailed Monte Carlo simulations of the electron transport in such a patient model to examine the characteristics of the resultant absorbed dose distributions as a function of both the electron beam energy as well as the number of beams for a particular type of treatment, namely, a prostate radiotherapy treatment. Each treatment is modeled as consisting of nine, five or three beam ports isocentrically distributed around the patient. An optimization algorithm is then applied to obtain the beam weights in each treatment plan. It is shown that for this particularly challenging case, both excellent target coverage and critical structure sparing can be obtained for energies in the order of 150MeV and for as few as three treatment ports, while significantly reducing the total energy absorbed by the patient with respect to a conventional megavoltage x-ray treatment.
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Affiliation(s)
- H M Garnica-Garza
- Centro de Investigación y de Estudios Avanzados del IPN Unidad Monterrey, Vía del Conocimiento 201 Parque PIIT, Apodaca, Nuevo León C.P. 66600, Mexico.
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46
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Madrid González OA, Rivera Montalvo T. Semiconductor diode characterization for total skin electron irradiation. Appl Radiat Isot 2014; 83 Pt C:214-7. [PMID: 24018291 DOI: 10.1016/j.apradiso.2013.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 04/18/2013] [Accepted: 06/05/2013] [Indexed: 10/26/2022]
Abstract
In this paper, a semiconductor diode characterization was performed. The diode characterization was completed using an electron beam with 4 MeV of energy. The semiconductor diode calibration used irradiation with an electron beam in an ion chamber. "In vivo" dosimetry was also conducted. The dosimetry results revealed that the semiconductor diode was a good candidate for use in the total skin electron therapy (TSET) treatment control.
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Affiliation(s)
- O A Madrid González
- Centro de investigación en Ciencia Aplicada y Tecnología Avanzada-Legaría del Instituto Politécnico Nacional, Legaría 694. Colonia Irrigación, 11500 México D.F.
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47
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Enosawa S, Dozen M, Tada Y, Hirasawa K. Electron Therapy Attenuated Elevated Alanine Aminotransferase and Oxidative Stress Values in Type 2 Diabetes-Induced Nonalcoholic Steatohepatitis of Rats. Cell Med 2013; 6:63-73. [PMID: 26858882 DOI: 10.3727/215517913x674225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Chronic oxidative stress plays a key role in the progression of nonalcoholic steatohepatitis (NASH). We examined the efficacy of antioxidative electron treatment on type 2 diabetes-induced NASH in a rat model. We established NASH model rats, induced by neonatal administration of streptozotocin and a high-fat diet, which exhibited pathologically high values of alanine aminotransferase (ALT), glucose, and malondialdehyde (MDA). The rats were exposed to electron discharge at very low energy for 4 weeks; this dose results in the reduction of Fe(3+) and glutathione disulfide in vitro. Serum ALT values were increased from baseline (8 weeks) to 125.0 ± 13 U/L at 10 weeks in the control group. In contrast, the values in the treated group did not show any increase at 10 weeks [87 ± 10 U/L (p = 0.0391)]. Hepatic MDA levels were also significantly decreased at 12 weeks (p < 0.05), but 8-hydroxy-2'-deoxyguanosine values were not statistically significant (p = 0.076). A gradual but steadily decreasing trend from initially high glucose levels was observed, though the values were not significant in 12-week-old animals (p = 0.074). However, the serum values of MDA, ALT, and glucose were well correlated. The progression of fibrosis as measured by increased serum levels of hyaluronic acid and histological examinations were not affected by the treatment in this model. Antioxidative electron treatment at very low energy attenuated the pathogenically elevated liver inflammation and oxidative stress, together with presumably impaired glucose metabolism in NASH rat model.
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Affiliation(s)
- Shin Enosawa
- Division for Advanced Medical Sciences, Clinical Research Center, National Center for Child Health and Development , Setagaya-ku, Tokyo , Japan
| | - Masaharu Dozen
- Division for Advanced Medical Sciences, Clinical Research Center, National Center for Child Health and Development, Setagaya-ku, Tokyo, Japan; †Research Unit, Cambwick Healthcare Corporation, Akishima City, Tokyo, Japan
| | - Yuki Tada
- † Research Unit, Cambwick Healthcare Corporation , Akishima City, Tokyo , Japan
| | - Keisuke Hirasawa
- † Research Unit, Cambwick Healthcare Corporation , Akishima City, Tokyo , Japan
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48
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Hensley FW, Major G, Edel C, Hauswald H, Bischof M. Technical and dosimetric aspects of the total skin electron beam technique implemented at Heidelberg University Hospital. Rep Pract Oncol Radiother 2013; 19:135-43. [PMID: 24936332 DOI: 10.1016/j.rpor.2013.07.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/04/2013] [Indexed: 12/25/2022] Open
Abstract
AIM To give a technical description and present the dosimetric proporties of the total skin electron beam technique implemented at Heidelberg University Hospital. BACKGROUND Techniques used for total skin electron beam irradiation were developed as early as in the 1960s to 1980s and have, since then, hardly changed. However, new measurements of the established methods allow deeper insight into the dose distributions and reasons for possible deviations from uniform dose. MATERIALS AND METHODS The TSEI technique applied at Heidelberg University Hospital since 1992 consists of irradiating the patient with a superposition of two beams of low energy electrons at gantry angles of 72° and 108° while he is rotating in a standing position on a turntable at 370 cm distance from the accelerator. The energy of the electron beam is degraded to 3.9 MeV by passing through an attenuator of 6 mm of Perspex. A recent re-measurement of the dose distribution is presented using modern dosimetry tools like a linear array of ionization chambers in combination with established methods like thermoluminescent detectors and film dosimetry. RESULTS The measurements show a strong dependence of dose uniformity on details of the setup like gantry angles. CONCLUSIONS Dose uniformity of -4/+8% to the majority of the patient's skin can be achieved, however, for the described rotational technique overdoses up to more than 20% in small regions seem unavoidable.
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Affiliation(s)
- Frank W Hensley
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Gerald Major
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Carolin Edel
- Department of Radiation Protection, Zentralbereich Neuenheimer Feld, University of Heidelberg, Im Neuenheimer Feld 327, 69120 Heidelberg, Germany
| | - Henrik Hauswald
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Marc Bischof
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
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49
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Park SH, Kim JC. Comparison of electron and x-ray beams for tumor bed boost irradiation in breast-conserving treatment. J Breast Cancer 2013; 16:300-7. [PMID: 24155759 PMCID: PMC3800726 DOI: 10.4048/jbc.2013.16.3.300] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 09/10/2013] [Indexed: 01/21/2023] Open
Abstract
Purpose This study aimed to compare the dosimetric profiles of electron beams (EB) and X-ray beams (XB) for boosting irradiation in breast cancer patients who underwent breast-conserving surgery and postoperative radiotherapy. Methods For 131 breast cancer patients who underwent breast-conserving surgery, we compared plans for EB and XB boost irradiation after whole-breast irradiation. The organs at risk (OAR) included the cardiac chambers, coronary arteries, ipsilateral lung, and skin. The conformity index (CI), inhomogeneity index (IHI), and dose-volume parameters for the planning target volume (PTV), and OAR were calculated. Postradiotherapy chest computed tomography scans were performed to detect radiation pneumonitis. Results XB plans showed a significantly better CI and IHI for the PTVs, compared to the EB plans. Regarding OAR sparing, the XB reduced the high-dose volume at the expense of an increased low-dose volume. In 33 patients whose radiation fields included nipples, IHI was higher in the EB plans, whereas the presence of a nipple in the radiation field did not interfere with the XB. EB-treated patients developed more subclinical radiation pneumonitis. Conclusion XB plans were superior to EB plans in terms of PTV coverage (homogeneity and conformity) and high-dose volume sparing in OAR when used as boost irradiation after breast-conserving surgery. A disadvantage of the XB plan was an increased low-dose volume in the OAR, but this was offset by the increased electron energy. Consequently, tailored plans with either XB or EB are necessary to adapt to patient anatomic variance and tumor bed geometric properties.
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Affiliation(s)
- Shin-Hyung Park
- Department of Radiation Oncology, Kyungpook National University School of Medicine, Daegu, Korea
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Fastner G, Sedlmayer F, Merz F, Deutschmann H, Reitsamer R, Menzel C, Stierle C, Farmini A, Fischer T, Ciabattoni A, Mirri A, Hager E, Reinartz G, Lemanski C, Orecchia R, Valentini V. IORT with electrons as boost strategy during breast conserving therapy in limited stage breast cancer: long term results of an ISIORT pooled analysis. Radiother Oncol 2013; 108:279-86. [PMID: 23830467 DOI: 10.1016/j.radonc.2013.05.031] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 02/23/2013] [Accepted: 05/11/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE Linac-based intraoperative radiotherapy with electrons (IOERT) was implemented to prevent local recurrences after breast conserving therapy (BCT) and was delivered as an intraoperative boost to the tumor bed prior to whole breast radiotherapy (WBI). A collaborative analysis has been performed by European ISIORT member institutions for long term evaluation of this strategy. MATERIAL AND METHODS Until 10/2005, 1109 unselected patients of any risk group have been identified among seven centers using identical methods, sequencing and dosage for intra- and postoperative radiotherapy. A median IOERT dose of 10 Gy was applied (90% reference isodose), preceding WBI with 50-54 Gy (single doses 1.7-2 Gy). RESULTS At a median follow up of 72.4 months (0.8-239), only 16 in-breast recurrences were observed, yielding a local tumor control rate of 99.2%. Relapses occurred 12.5-151 months after primary treatment. In multivariate analysis only grade 3 reached significance (p=0.031) to be predictive for local recurrence development. Taking into account patient age, annual in-breast recurrence rates amounted 0.64%, 0.34%, 0.21% and 0.16% in patients <40 years; 40-49 years; 50-59 years and ≥ 60 years, respectively. CONCLUSION In all risk subgroups, a 10 Gy IOERT boost prior to WBI provided outstanding local control rates, comparing favourably to all trials with similar length of follow up.
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Affiliation(s)
- Gerd Fastner
- Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University, Salzburg, Austria.
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