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Gauter-Fleckenstein B, Schönig S, Mertens L, Oppitz H, Siebenlist K, Ehmann M, Fleckenstein J. Effect of simultaneous integrated boost concepts on photoneutron and distant out-of-field doses in VMAT for prostate cancer. Strahlenther Onkol 2024; 200:219-229. [PMID: 37707518 PMCID: PMC10876496 DOI: 10.1007/s00066-023-02138-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 08/08/2023] [Indexed: 09/15/2023]
Abstract
BACKGROUND A simultaneous integrated boost (SIB) may result in increased out-of-field (DOOF) and photoneutron (HPN) doses in volumetric modulated arc therapy (VMAT) for prostate cancer (PCA). This work therefore aimed to compare DOOF and HPN in flattened (FLAT) and flattening filter-free (FFF) 6‑MV and 10-MV VMAT treatment plans with and without SIB. METHODS Eight groups of 30 VMAT plans for PCA with 6 MV or 10 MV, with or without FF and with uniform (2 Gy) or SIB target dose (2.5/3.0 Gy) prescriptions (CONV, SIB), were generated. All 240 plans were delivered on a slab-phantom and compared with respect to measured DOOF and HPN in 61.8 cm distance from the isocenter. The 6‑ and 10-MV flattened VMAT plans with conventional fractionation (6- and 10-MV FLAT CONV) served as standard reference groups. Doses were analyzed as a function of delivered monitor units (MU) and weighted equivalent square field size Aeq. Pearson's correlation coefficients between the presented quantities were determined. RESULTS The SIB plans resulted in decreased HPN over an entire prostate RT treatment course (10-MV SIB vs. CONV -38.2%). Omission of the flattening filter yielded less HPN (10-MV CONV -17.2%; 10-MV SIB -22.5%). The SIB decreased DOOF likewise by 39% for all given scenarios, while the FFF mode reduced DOOF on average by 60%. A strong Pearson correlation was found between MU and HPN (r > 0.9) as well as DOOF (0.7 < r < 0.9). CONCLUSION For a complete treatment, SIB reduces both photoneutron and OOF doses to almost the same extent as FFF deliveries. It is recommended to apply moderately hypofractionated 6‑MV SIB FFF-VMAT when considering photoneutron or OOF doses.
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Affiliation(s)
- Benjamin Gauter-Fleckenstein
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany.
| | - Sebastian Schönig
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany
| | - Lena Mertens
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany
| | - Hans Oppitz
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany
| | - Kerstin Siebenlist
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany
| | - Michael Ehmann
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany
| | - Jens Fleckenstein
- Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany
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2
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De Saint-Hubert M, Boissonnat G, Schneider U, Bäumer C, Verbeek N, Esser J, Wulff J, Stuckmann F, Suesselbeck F, Nabha R, Dabin J, Vasi F, Radonic S, Rodriguez M, Simon AC, Journy N, Timmermann B, Thierry-Chef I, Brualla L. Complete patient exposure during paediatric brain cancer treatment for photon and proton therapy techniques including imaging procedures. Front Oncol 2023; 13:1222800. [PMID: 37795436 PMCID: PMC10546320 DOI: 10.3389/fonc.2023.1222800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 08/21/2023] [Indexed: 10/06/2023] Open
Abstract
Background In radiotherapy, especially when treating children, minimising exposure of healthy tissue can prevent the development of adverse outcomes, including second cancers. In this study we propose a validated Monte Carlo framework to evaluate the complete patient exposure during paediatric brain cancer treatment. Materials and methods Organ doses were calculated for treatment of a diffuse midline glioma (50.4 Gy with 1.8 Gy per fraction) on a 5-year-old anthropomorphic phantom with 3D-conformal radiotherapy, intensity modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT) and intensity modulated pencil beam scanning (PBS) proton therapy. Doses from computed tomography (CT) for planning and on-board imaging for positioning (kV-cone beam CT and X-ray imaging) accounted for the estimate of the exposure of the patient including imaging therapeutic dose. For dose calculations we used validated Monte Carlo-based tools (PRIMO, TOPAS, PENELOPE), while lifetime attributable risk (LAR) was estimated from dose-response relationships for cancer induction, proposed by Schneider et al. Results Out-of-field organ dose equivalent data of proton therapy are lower, with doses between 0.6 mSv (testes) and 120 mSv (thyroid), when compared to photon therapy revealing the highest out-of-field doses for IMRT ranging between 43 mSv (testes) and 575 mSv (thyroid). Dose delivered by CT ranged between 0.01 mSv (testes) and 72 mSv (scapula) while a single imaging positioning ranged between 2 μSv (testes) and 1.3 mSv (thyroid) for CBCT and 0.03 μSv (testes) and 48 μSv (scapula) for X-ray. Adding imaging dose from CT and daily CBCT to the therapeutic demonstrated an important contribution of imaging to the overall radiation burden in the course of treatment, which is subsequently used to predict the LAR, for selected organs. Conclusion The complete patient exposure during paediatric brain cancer treatment was estimated by combining the results from different Monte Carlo-based dosimetry tools, showing that proton therapy allows significant reduction of the out-of-field doses and secondary cancer risk in selected organs.
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Affiliation(s)
| | | | - Uwe Schneider
- Physik Institut, Universitat Zürich, Zürich, Switzerland
| | - Christian Bäumer
- West German Proton Therapy Centre Essen WPE, Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
- Radiation Oncology and Imaging, German Cancer Consortium DKTK, Essen, Germany
- Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Nico Verbeek
- West German Proton Therapy Centre Essen WPE, Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
| | - Johannes Esser
- West German Proton Therapy Centre Essen WPE, Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
- Faculty of Mathematics and Science Institute of Physics and Medical Physics, Heinrich-Heine University, Düsseldorf, Germany
| | - Jörg Wulff
- West German Proton Therapy Centre Essen WPE, Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
| | - Florian Stuckmann
- West German Proton Therapy Centre Essen WPE, Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
| | - Finja Suesselbeck
- West German Proton Therapy Centre Essen WPE, Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
| | - Racell Nabha
- Belgian Nuclear Research Center (SCK CEN), Mol, Belgium
| | - Jérémie Dabin
- Belgian Nuclear Research Center (SCK CEN), Mol, Belgium
| | - Fabiano Vasi
- Physik Institut, Universitat Zürich, Zürich, Switzerland
| | | | - Miguel Rodriguez
- Hospital Paitilla, Panama City, Panama
- Instituto de Investigaciones Científicas y de Alta Tecnología INDICASAT-AIP, Panama City, Panama
| | | | - Neige Journy
- INSERM U1018, Paris Sud-Paris Saclay University, Villejuif, France
| | - Beate Timmermann
- West German Proton Therapy Centre Essen WPE, Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
- Radiation Oncology and Imaging, German Cancer Consortium DKTK, Essen, Germany
- Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
- Department of Particle Therapy, University Hospital Essen, Essen, Germany
| | - Isabelle Thierry-Chef
- Barcelona Institute of Global Health (ISGlobal), Barcelona, Spain
- University Pompeu Fabra, Barcelona, Spain
- CIBER Epidemiología y Salud Pública, Madrid, Spain
| | - Lorenzo Brualla
- West German Proton Therapy Centre Essen WPE, Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
- Radiation Oncology and Imaging, German Cancer Consortium DKTK, Essen, Germany
- Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
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3
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Hassanpour M, Hassanpour M, Rezaie M, Khezripour S, Faruque MRI, Khandaker MU. The application of graphene/h-BN metamaterial in medical linear accelerators for reducing neutron leakage in the treatment room. Phys Eng Sci Med 2023; 46:1023-1032. [PMID: 37219796 DOI: 10.1007/s13246-023-01269-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 04/28/2023] [Indexed: 05/24/2023]
Abstract
Neutrons can be generated in medical linear accelerators (Linac) due to the interaction of high-energy photons (> 10 MeV) with the components of the accelerator head. The generated photoneutrons may penetrate the treatment room if a suitable neutron shield is not used. This causes a biological risk to the patient and occupational workers. The use of appropriate materials in the barriers surrounding the bunker may be effective in preventing the transmission of neutrons from the treatment room to the outside. In addition, neutrons are present in the treatment room due to leakage in the Linac's head. This study aims to reduce the transmission of neutrons from the treatment room by using graphene/hexagonal boron nitride (h-BN) metamaterial as a neutron shielding material. MCNPX code was used to model three layers of graphene/h-BN metamaterial around the target and other components of the linac, and to investigate its effect on the photon spectrum and photoneutrons. Results indicate that the first layer of a graphene/h-BN metamaterial shield around the target improves photon spectrum quality at low energies, whereas the second and third layers have no significant effect. Regarding neutrons, three layers of the metamaterial results in a 50% reduction in the number of neutrons in the air within the treatment room.
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Affiliation(s)
- Mehdi Hassanpour
- Space Science Centre (ANGKASA), Institute of Climate Change (IPI), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.
| | - Marzieh Hassanpour
- Space Science Centre (ANGKASA), Institute of Climate Change (IPI), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Mohammadreza Rezaie
- Department of Nuclear Engineering, Faculty of Modern Sciences and Technologies, Graduate University of Advanced Technology, Kerman, Iran.
| | - Saeedeh Khezripour
- Department of photonics, Faculty of Modern Science and Technology, Graduate University of Advanced Technology, Kerman, Iran
| | - Mohammad Rashed Iqbal Faruque
- Space Science Centre (ANGKASA), Institute of Climate Change (IPI), Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.
| | - Mayeen Uddin Khandaker
- Centre for Applied Physics and Radiation Technologies, School of Engineering and Technology, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia
- Department of General Educational Development, Faculty of Science and Information Technology, Daffodil International University, DIU Rd, Dhaka, 1341, Bangladesh
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4
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RapidPlan models for prostate radiotherapy treatment planning with 10-MV photon beams. JOURNAL OF RADIOTHERAPY IN PRACTICE 2022. [DOI: 10.1017/s1460396922000267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Introduction:
The RapidPlan is a radiotherapy planning tool that uses a dataset of approved plans to predict the dose distribution and automatically generates the dose–volume constraints for optimisation of the new plan. This study compares three strategies of model building for the treatment of prostate cancer with the 10-MV photon beam.
Methods:
Three models for prostate treatment were compared: Model 6X, Model10X and Model6Xrefined. Model6X is already used in our department and was trained on treatment plans based on the 6-MV photon beam. Model10X was trained on treatment plans based on the 10-MV photon beam and manually optimised by an experienced medical physicist. Finally, Model6Xrefined was trained on plans automatically created by the Model6X, but using the 10-MV photon beam. The three models were used to generate 25 new plans with the 10-MV photon beam.
Results:
Model10X generated plans with 2 Gy lower mean dose to bladder-PTV and rectum-PTV volumes and 8% lower V15Gy at bladder and rectum volumes, although the number of monitor units increased by 170 on average.
Conclusions:
The model trained on manually optimised plans generated plans with higher normal tissue sparing. However, model building is a time-consuming process, so a cost–benefit balance should be performed.
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5
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De Saint-Hubert M, Verbeek N, Bäumer C, Esser J, Wulff J, Nabha R, Van Hoey O, Dabin J, Stuckmann F, Vasi F, Radonic S, Boissonnat G, Schneider U, Rodriguez M, Timmermann B, Thierry-Chef I, Brualla L. Validation of a Monte Carlo Framework for Out-of-Field Dose Calculations in Proton Therapy. Front Oncol 2022; 12:882489. [PMID: 35756661 PMCID: PMC9213663 DOI: 10.3389/fonc.2022.882489] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 05/04/2022] [Indexed: 11/30/2022] Open
Abstract
Proton therapy enables to deliver highly conformed dose distributions owing to the characteristic Bragg peak and the finite range of protons. However, during proton therapy, secondary neutrons are created, which can travel long distances and deposit dose in out-of-field volumes. This out-of-field absorbed dose needs to be considered for radiation-induced secondary cancers, which are particularly relevant in the case of pediatric treatments. Unfortunately, no method exists in clinics for the computation of the out-of-field dose distributions in proton therapy. To help overcome this limitation, a computational tool has been developed based on the Monte Carlo code TOPAS. The purpose of this work is to evaluate the accuracy of this tool in comparison to experimental data obtained from an anthropomorphic phantom irradiation. An anthropomorphic phantom of a 5-year-old child (ATOM, CIRS) was irradiated for a brain tumor treatment in an IBA Proteus Plus facility using a pencil beam dedicated nozzle. The treatment consisted of three pencil beam scanning fields employing a lucite range shifter. Proton energies ranged from 100 to 165 MeV. A median dose of 50.4 Gy(RBE) with 1.8 Gy(RBE) per fraction was prescribed to the initial planning target volume (PTV), which was located in the cerebellum. Thermoluminescent detectors (TLDs), namely, Li-7-enriched LiF : Mg, Ti (MTS-7) type, were used to detect gamma radiation, which is produced by nuclear reactions, and secondary as well as recoil protons created out-of-field by secondary neutrons. Li-6-enriched LiF : Mg,Cu,P (MCP-6) was combined with Li-7-enriched MCP-7 to measure thermal neutrons. TLDs were calibrated in Co-60 and reported on absorbed dose in water per target dose (μGy/Gy) as well as thermal neutron dose equivalent per target dose (μSv/Gy). Additionally, bubble detectors for personal neutron dosimetry (BD-PND) were used for measuring neutrons (>50 keV), which were calibrated in a Cf-252 neutron beam to report on neutron dose equivalent dose data. The Monte Carlo code TOPAS (version 3.6) was run using a phase-space file containing 1010 histories reaching an average standard statistical uncertainty of less than 0.2% (coverage factor k = 1) on all voxels scoring more than 50% of the maximum dose. The primary beam was modeled following a Fermi–Eyges description of the spot envelope fitted to measurements. For the Monte Carlo simulation, the chemical composition of the tissues represented in ATOM was employed. The dose was tallied as dose-to-water, and data were normalized to the target dose (physical dose) to report on absorbed doses per target dose (mSv/Gy) or neutron dose equivalent per target dose (μSv/Gy), while also an estimate of the total organ dose was provided for a target dose of 50.4 Gy(RBE). Out-of-field doses showed absorbed doses that were 5 to 6 orders of magnitude lower than the target dose. The discrepancy between TLD data and the corresponding scored values in the Monte Carlo calculations involving proton and gamma contributions was on average 18%. The comparison between the neutron equivalent doses between the Monte Carlo simulation and the measured neutron doses was on average 8%. Organ dose calculations revealed the highest dose for the thyroid, which was 120 mSv, while other organ doses ranged from 18 mSv in the lungs to 0.6 mSv in the testes. The proposed computational method for routine calculation of the out-of-the-field dose in proton therapy produces results that are compatible with the experimental data and allow to calculate out-of-field organ doses during proton therapy.
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Affiliation(s)
- Marijke De Saint-Hubert
- Research in Dosimetric Applications, Belgian Nuclear Research Center (SCK CEN), Mol, Belgium
| | - Nico Verbeek
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
| | - Christian Bäumer
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,Radiation Oncology and Imaging, German Cancer Consortium DKTK, Heidelberg, Germany.,Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Johannes Esser
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,Faculty of Mathematics and Science Institute of Physics and Medical Physics. Heinrich-Heine University, Düsseldorf, Germany
| | - Jörg Wulff
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany
| | - Racell Nabha
- Research in Dosimetric Applications, Belgian Nuclear Research Center (SCK CEN), Mol, Belgium
| | - Olivier Van Hoey
- Research in Dosimetric Applications, Belgian Nuclear Research Center (SCK CEN), Mol, Belgium
| | - Jérémie Dabin
- Research in Dosimetric Applications, Belgian Nuclear Research Center (SCK CEN), Mol, Belgium
| | - Florian Stuckmann
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,Faculty of Mathematics and Science Institute of Physics and Medical Physics. Heinrich-Heine University, Düsseldorf, Germany.,Klinikum Fulda GAG, Universitätsmedizin Marburg, Fulda, Zurich, Germany
| | - Fabiano Vasi
- Physik Institut, Universität Zürich, Zürich, Switzerland
| | | | | | - Uwe Schneider
- Physik Institut, Universität Zürich, Zürich, Switzerland
| | - Miguel Rodriguez
- Hospital Paitilla, Panama City, Panama.,Instituto de Investigaciones Cientificas y de Alta Tecnología INDICASAT-AIP, Panama City, Panama
| | - Beate Timmermann
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,Faculty of Medicine, University of Duisburg-Essen, Essen, Germany.,Radiation Oncology and Imaging, German Cancer Consortium DKTK, Heidelberg, Germany.,Department of Particle Therapy, University Hospital Essen, Essen, Germany
| | - Isabelle Thierry-Chef
- Radiation Programme, Barcelona Institute for Global Health (ISGlobal), Barcelona, Spain.,University Pompeu Fabra, Barcelona, Spain.,CIBER Epidemiología y Salud Pública, Madrid, Spain
| | - Lorenzo Brualla
- West German Proton Therapy Centre Essen WPE, Essen, Germany.,West German Cancer Center (WTZ), Essen, Germany.,Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
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6
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Domingo C, Lagares JI, Romero-Expósito M, Sánchez-Nieto B, Nieto-Camero JJ, Terrón JA, Irazola L, Dasu A, Sánchez-Doblado F. Peripheral Organ Equivalent Dose Estimation Procedure in Proton Therapy. Front Oncol 2022; 12:882476. [PMID: 35692801 PMCID: PMC9176390 DOI: 10.3389/fonc.2022.882476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/19/2022] [Indexed: 11/23/2022] Open
Abstract
The aim of this work is to present a reproducible methodology for the evaluation of total equivalent doses in organs during proton therapy facilities. The methodology is based on measuring the dose equivalent in representative locations inside an anthropomorphic phantom where photon and neutron dosimeters were inserted. The Monte Carlo simulation was needed for obtaining neutron energy distribution inside the phantom. The methodology was implemented for a head irradiation case in the passive proton beam of iThemba Labs (South Africa). Thermoluminescent dosimeter (TLD)-600 and TLD-700 pairs were used as dosimeters inside the phantom and GEANT code for simulations. In addition, Bonner sphere spectrometry was performed inside the treatment room to obtain the neutron spectra, some relevant neutron dosimetric quantities per treatment Gy, and a percentual distribution of neutron fluence and ambient dose equivalent in four energy groups, at two locations. The neutron spectrum at one of those locations was also simulated so that a reasonable agreement between simulation and measurement allowed a validation of the simulation. Results showed that the total out-of-field dose equivalent inside the phantom ranged from 1.4 to 0.28 mSv/Gy, mainly due to the neutron contribution and with a small contribution from photons, 10% on average. The order of magnitude of the equivalent dose in organs was similar, displaying a slow reduction in values as the organ is farther from the target volume. These values were in agreement with those found by other authors in other passive beam facilities under similar irradiation and measurement conditions.
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Affiliation(s)
- Carles Domingo
- Departament de Fisica, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Juan Ignacio Lagares
- Unidad de Aplicaciones Médicas, Departamento de Tecnología, Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
| | | | | | | | - Jose Antonio Terrón
- Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla, Spain
| | - Leticia Irazola
- Servicio de Radiofísica y Protección Radiológica, Clínica Universidad de Navarra, Pamplona, Spain
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden.,Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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7
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Measurement of neutron equivalent dose in the thyroid, chiasma, and lens for patients undergoing pelvic radiotherapy: A phantom study. Appl Radiat Isot 2022; 184:110188. [DOI: 10.1016/j.apradiso.2022.110188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/18/2022] [Accepted: 03/04/2022] [Indexed: 11/20/2022]
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8
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Majer M, Ambrožová I, Davídková M, De Saint-Hubert M, Kasabašić M, Knežević Ž, Kopeć R, Krzempek D, Krzempek K, Miljanić S, Mojżeszek N, Veršić I, Stolarczyk L, Harrison RM, Olko P. Out-of-field doses in pediatric craniospinal irradiations with 3D-CRT, VMAT and scanning proton radiotherapy - a phantom study. Med Phys 2022; 49:2672-2683. [PMID: 35090187 DOI: 10.1002/mp.15493] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 12/01/2021] [Accepted: 01/12/2022] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Craniospinal irradiation (CSI) has greatly increased survival rates for patients with a diagnosis of medulloblastoma and other primitive neuroectodermal tumors. However, as it includes exposure of a large volume of healthy tissue to unwanted doses, there is a strong concern about the complications of the treatment, especially for the children. To estimate the risk of second cancers and other unwanted effects, out-of-field dose assessment is necessary. The purpose of this study is to evaluate and compare out-of-field doses in pediatric CSI treatment using conventional and advanced photon radiotherapy (RT) and advanced proton therapy. To our knowledge, it is the first such comparison based on in-phantom measurements. Additionally, for out-of-field doses during photon RT in this and other studies, comparisons were made using analytical modeling. METHODS In order to describe the out-of-field doses absorbed in a pediatric patient during actual clinical treatment, an anthropomorphic phantom which mimics the 10-year-old child was used. Photon 3D-conformal radiotherapy (3D-CRT) and two advanced, highly conformal techniques: photon volumetric modulated arc therapy (VMAT) and active pencil beam scanning (PBS) proton radiotherapy were used for CSI treatment. Radiophotoluminescent (RPL) and poly-allyl-diglycol-carbonate (PADC) nuclear track detectors were used for photon and neutron dosimetry in the phantom, respectively. Out-of-field doses from neutrons were expressed in terms of dose equivalent. A two-Gaussian model was implemented for out-of-field doses during photon RT. RESULTS The mean VMAT photon doses per target dose to all organs in this study were under 50% of the target dose (i.e., <500 mGy/Gy), while the mean 3D-CRT photon dose to oesophagus, gall bladder and thyroid, exceeded that value. However, for 3D-CRT, better sparing was achieved for eyes and lungs. The mean PBS photon doses for all organs were up to 3 orders of magnitude lower compared to VMAT and 3D-CRT and exceeded 10 mGy/Gy only for the oesophagus, intestine and lungs. The mean neutron dose equivalent during PBS for 8 organs of interest (thyroid, breasts, lungs, liver, stomach, gall bladder, bladder, prostate) ranged from 1.2 mSv/Gy for bladder to 23.1 mSv/Gy for breasts. Comparison of out-of-field doses in this and other phantom studies found in the literature showed that a simple and fast two-Gaussian model for out-of-field doses as a function of distance from the field edge can be applied in a CSI using photon RT techniques. CONCLUSIONS PBS is the most promising technique for out-of-field dose reduction in comparison to photon techniques. Among photon techniques, VMAT is a preferred choice for most of out-of-field organs and especially for the thyroid, while doses for eyes, breasts and lungs, are lower for 3D-CRT. For organs outside the field edge, a simple analytical model can be helpful for clinicians involved in treatment planning using photon RT but also for retrospective data analysis for cancer risk estimates and epidemiology in general. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Marija Majer
- Ruđer Bošković Institute, Zagreb, 10000, Croatia
| | - Iva Ambrožová
- Nuclear Physics Institute of the CAS, Řež, CZ-250 68, Czech Republic
| | - Marie Davídková
- Nuclear Physics Institute of the CAS, Řež, CZ-250 68, Czech Republic
| | | | - Mladen Kasabašić
- Osijek University Hospital, Osijek, 31000, Croatia.,Faculty of Medicine Osijek, J.J. Strossmayer University of Osijek, Osijek, 31000, Croatia
| | | | - Renata Kopeć
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, 31-342, Poland
| | - Dawid Krzempek
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, 31-342, Poland
| | - Katarzyna Krzempek
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, 31-342, Poland
| | | | - Natalia Mojżeszek
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, 31-342, Poland
| | - Ivan Veršić
- Department of Physics, Faculty of Science, University of Zagreb, Zagreb, 10000, Croatia
| | - Liliana Stolarczyk
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, 31-342, Poland.,Danish Center for Particle Therapy, Aarhus, Denmark
| | - Roger M Harrison
- University of Newcastle, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Paweł Olko
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, 31-342, Poland
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9
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Stick LB, Lægdsmand PMT, Bjerre HL, Høyer M, Jensen K, Jensen MF, Kronborg MB, Offersen BV, Kronborg CJS. Spot-scanning proton therapy for targets with adjacent cardiac implantable electronic devices – Strategies for breast and head & neck cancer. Phys Imaging Radiat Oncol 2022; 21:66-71. [PMID: 35243034 PMCID: PMC8861136 DOI: 10.1016/j.phro.2022.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 11/16/2022] Open
Abstract
Secondary neutron dose was calculated for pacemakers and implantable cardioverter defibrillators for patients with breast and head & neck cancer. Decision algorithms for selecting patients with targets adjacent to pacemakers and implantable cardioverter defibrillators for proton therapy were established. Eligibility for proton therapy depends on individual evaluation for some patients. The expected gain from proton therapy should outweigh the risk of device malfunction.
Background and purpose Cardiac implantable electronic device (CIED) malfunctions can be induced by secondary neutron dose from spot-scanning proton therapy. A recent in-vitro study investigating secondary neutron dose to CIEDs up to 7 mSv per fraction found that exposure of secondary neutrons in this range was clinically manageable. This study presents decision algorithms proposed by a national expert group for selection of patients with breast and head & neck (H&N) cancer with CIEDs adjacent to target for proton therapy based on the 7 mSv threshold. Methods and materials Ten patients with breast cancer and five with H&N cancer were included in the study. Five patients with breast cancer received photon therapy with CIED and proton plans were retrospectively created. The remaining patients received proton therapy without CIED and a worst-case position of a virtual CIED was retrospectively delineated. Secondary neutron dose was estimated as ambient dose equivalent H*(10) using Monte Carlo simulations. Results For patients with breast cancer and with contralateral CIED, the secondary neutron dose to the CIED was below 7 mSv per fraction for CTV < 1500 cm3 in 2 Gy fractions and CTV < 1000 cm3 in 2.67 Gy fractions. The secondary neutron dose to the CIED was below 7 mSv per fraction for all patients with H&N cancer. Conclusions Simulations of neutron exposure suggest that proton therapy is feasible for most patients with CIED adjacent to target. This forms the basis for decision algorithms for selection of patients with CIED for proton therapy.
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Affiliation(s)
- Line Bjerregaard Stick
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Corresponding author at: Danish Centre for Particle Therapy, Aarhus University Hospital, Palle Juul-Jensens Blvd. 99, 8200 Aarhus, Denmark.
| | | | - Henrik Laurits Bjerre
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark
| | - Morten Høyer
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Kenneth Jensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | | | | | - Birgitte Vrou Offersen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
- Department of Experimental Clinical Oncology & Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
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Chargari C, Giraud P, Lacornerie T, Cosset JM. Prevention of radiation-induced cancers. Cancer Radiother 2021; 26:92-95. [PMID: 34953687 DOI: 10.1016/j.canrad.2021.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The issue of radiation-induced cancers must be taken into consideration during therapeutic irradiations. Risk factors for radiation-induced cancer include: the age of the patients, the volumes irradiated, the presence of risk cofactors and the exposure of critical organs. Those should be part of the therapeutic decision, in terms of indication, as well as choice of the radiotherapy technique (including repositioning systems). We present the update of the recommendations of the French society for radiation oncology on the modalities for preventing radiation-induced cancers.
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Affiliation(s)
- C Chargari
- Département d'oncologie radiothérapie, Gustave-Roussy Cancer Campus, 114, rue Édouard-Vaillant, 94800 Villejuif, France.
| | - P Giraud
- Département d'oncologie radiothérapie, hôpital européen Georges-Pompidou, université de Paris, 20, rue Leblanc, 75015 Paris, France
| | - T Lacornerie
- Service de physique médicale, centre Oscar-Lambret, 3, rue Frédéric-Combemale, 59000 Lille, France
| | - J-M Cosset
- Centre de radiothérapie Charlebourg/La Défense, groupe Amethyst, 65, avenue Foch, 92250 La Garenne-Colombes, France
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11
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Yang S, Zhao J, Zhuo W, Shen H, Chen B. Measurement of therapeutic 12C beam in a water phantom using CR-39. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2021; 41:279-290. [PMID: 33401257 DOI: 10.1088/1361-6498/abd88c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/05/2021] [Indexed: 06/12/2023]
Abstract
The motivation for this study was to explore a new method to test the particle spatial distribution for a therapeutic carbon beam. CR-39 plastic nuclear track detectors were irradiated to a 276.5 MeV u-1mono-energy carbon beam at the heavy ion facility in the Shanghai Proton and Heavy Ion Center. The spatial distribution of the primary carbon beam and secondary fragments in a water phantom were systematically analyzed both in the transverse direction (perpendicular to the projection direction of the primary beam) and at different depths in the longitudinal direction (along the projection direction of the primary beam) with measured tracks on the CR-39 detectors. Meanwhile, the theoretically spatial distribution and linear energy transfer (LET) spectra of the primary beam and secondary fragments were calculated using the Monte Carlo (MC) toolkit Geant4. The results showed that the CR-39 detectors are capable of providing high lateral resolution of carbon ion at different depths. In the range of the primary carbon beam, the beam width simulated with MC is in good agreement with that of experimental measurement. The track size registered in the CR-39 has a good correlation with the particle LET. These findings indicate that the CR-39 can be used for measuring both the particle flux and its spatial distribution of carbon ions.
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Affiliation(s)
- Shiyan Yang
- Institute of Modern Physics, Department of Nuclear Science and Technology, Fudan University, Shanghai 200433, People's Republic of China
- Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University, Shanghai 200433, People's Republic of China
| | - Jingfang Zhao
- Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai 201315, People's Republic of China
- ShangHai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai 201315, People's Republic of China
| | - Weihai Zhuo
- Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University, Shanghai 200433, People's Republic of China
- Institute of Radiation Medicine, Fudan University, Shanghai 200032, People's Republic of China
| | - Hao Shen
- Institute of Modern Physics, Department of Nuclear Science and Technology, Fudan University, Shanghai 200433, People's Republic of China
- Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University, Shanghai 200433, People's Republic of China
| | - Bo Chen
- Institute of Radiation Medicine, Fudan University, Shanghai 200032, People's Republic of China
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12
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Bjerre HL, Kronborg MB, Nielsen JC, Høyer M, Jensen MF, Zaremba T, Lægdsmand PMT, Søndergaard CS, Nyström H, Kronborg CJS. Risk of Cardiac Implantable Electronic Device Malfunctioning During Pencil Beam Proton Scanning in an In Vitro Setting. Int J Radiat Oncol Biol Phys 2021; 111:186-195. [PMID: 33845147 DOI: 10.1016/j.ijrobp.2021.03.053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/08/2021] [Accepted: 03/30/2021] [Indexed: 01/08/2023]
Abstract
PURPOSE Cardiac implantable electronic devices (CIED) are sensitive to scattered secondary neutrons from proton beam irradiation. This experimental in vitro study investigated risk of CIED errors during pencil beam proton therapy. METHODS AND MATERIALS We used 62 explanted CIEDs from 4 manufacturers; 49 CIEDs were subjected to a simulated clinical protocol with daily 2 Gy relative biological effectiveness fractions prescribed to the phantom. Devices were located at 3 different lateral distances from the spread-out Bragg peak to investigate the risk of permanent or temporary device errors. Additionally, 13 devices with leads connected were monitored live during consecutive irradiations to investigate the risk of noise, over- or undersense, pace inhibition, and inappropriate shock therapy. RESULTS We detected 61 reset errors in 1728 fractions, and all except 1 CIED were reprogrammed to normal function. All, except 1 reset, occurred in devices from the same manufacturer. These were successfully reprogrammed to normal function. The 1 remaining CIED was locked in permanent safety mode. Secondary neutron dose, as estimated by Monte Carlo simulations, was found to significantly increase the odds of CIED resets by 55% per mSv. Clinically significant battery depletion was observed in 5 devices. We observed no noise, over- or undersense, pace inhibition, or inappropriate shock therapy during 362 fractions of live monitoring. CONCLUSIONS Reprogrammable CIED reset was the most commonly observed malfunction during proton therapy, and reset risk depended on secondary neutron exposure. The benefits of proton therapy are expected to outweigh the risk of CIED malfunctioning for most patients.
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Affiliation(s)
- Henrik Laurits Bjerre
- Department of Cardiology, Aarhus University Hospital, Denmark; Danish Centre for Particle Therapy, Aarhus University Hospital, Denmark.
| | | | | | - Morten Høyer
- Danish Centre for Particle Therapy, Aarhus University Hospital, Denmark
| | | | - Tomas Zaremba
- Department of Cardiology, Aalborg University Hospital, Denmark
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13
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Puchalska M. Modelling and measurements of distributions in an adult human phantom undergoing proton scanning beam radiotherapy: lung- and prostate-located tumours. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2021; 60:243-256. [PMID: 33651168 PMCID: PMC8116245 DOI: 10.1007/s00411-021-00895-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Proton radiotherapy has been shown to offer a significant dosimetric advantage in cancer patients, in comparison to conventional radiotherapy, with a decrease in dose to healthy tissue and organs at risk, because the bulk of the beam energy is deposited in the Bragg peak to be located within a tumour. However, it should be kept in mind that radiotherapy of cancer is still accompanied by adverse side effects, and a better understanding and improvement of radiotherapy can extend the life expectancy of patients following the treatment of malignant tumours. In this study, the dose distributions measured with thermoluminescent detectors (TLDs) inside a tissue-equivalent adult human phantom exposed for lung and prostate cancer using the modern proton beam scanning radiotherapy technique were compared. Since the TLD detection efficiency depends on the ionization density of the radiation to be detected, and since this efficiency is detector specific, four different types of TLDs were used to compare their response in the mixed radiation fields. Additionally, the dose distributions from two different cancer treatment modalities were compared using the selected detectors. The measured dose values were benchmarked against Monte Carlo simulations and available literature data. The results indicate an increase in the lateral dose with an increase of the primary proton energy. However, the radiation quality factor of the mixed radiation increases by 20% in the vicinity to the target for the lower initial proton energy, due to the production of secondary charged particles of low-energy and short range. For the cases presented here the MTS-N TLD detector seems to be the most optimal tool for dose measurements within the target volume, while the MCP-N TLD detector, due to an interplay of its enhanced thermal neutron response and decreased detection efficiency to highly ionising radiation, is a better choice for the out-of-field measurements. The pairs of MTS-6 and MTS-7 TLDs used also in this study allowed for a direct measurement of the neutron dose equivalent. Before it can be concluded that they offer an alternative to the time-consuming nuclear track detectors, however, more research is needed to unambiguously confirm whether this observation was just accidental or whether it only applies to certain cases. Since there is no universal detector, which would allow the determination of the dosimetric quantities relevant for risk estimation, this work expands the knowledge necessary to improve the quality of dosimetry data and might help scientists and clinicians in choosing the right tools to measure radiation doses in mixed radiation fields.
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Affiliation(s)
- Monika Puchalska
- Radiation Physics, Technische Universität Wien, Stadionalle 2, 1020, Vienna, Austria.
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14
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Wochnik A, Stolarczyk L, Ambrožová I, Davídková M, De Saint-Hubert M, Domański S, Domingo C, Knežević Ž, Kopeć R, Kuć M, Majer M, Mojżeszek N, Mares V, Martínez-Rovira I, Caballero-Pacheco MÁ, Pyszka E, Swakoń J, Trinkl S, Tisi M, Harrison R, Olko P. Out-of-field doses for scanning proton radiotherapy of shallowly located paediatric tumours-a comparison of range shifter and 3D printed compensator. Phys Med Biol 2021; 66:035012. [PMID: 33202399 DOI: 10.1088/1361-6560/abcb1f] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The lowest possible energy of proton scanning beam in cyclotron proton therapy facilities is typically between 60 and 100 MeV. Treatment of superficial lesions requires a pre-absorber to deliver doses to shallower volumes. In most of the cases a range shifter (RS) is used, but as an alternative solution, a patient-specific 3D printed proton beam compensator (BC) can be applied. A BC enables further reduction of the air gap and consequently reduction of beam scattering. Such pre-absorbers are additional sources of secondary radiation. The aim of this work was the comparison of RS and BC with respect to out-of-field doses for a simulated treatment of superficial paediatric brain tumours. EURADOS WG9 performed comparative measurements of scattered radiation in the Proteus C-235 IBA facility (Cyclotron Centre Bronowice at the Institute of Nuclear Physics, CCB IFJ PAN, Kraków, Poland) using two anthropomorphic phantoms-5 and 10 yr old-for a superficial target in the brain. Both active detectors located inside the therapy room, and passive detectors placed inside the phantoms were used. Measurements were supplemented by Monte Carlo simulation of the radiation transport. For the applied 3D printed pre-absorbers, out-of-field doses from both secondary photons and neutrons were lower than for RS. Measurements with active environmental dosimeters at five positions inside the therapy room indicated that the RS/BC ratio of the out-of-field dose was also higher than one, with a maximum of 1.7. Photon dose inside phantoms leads to higher out-of-field doses for RS than BC to almost all organs with the highest RS/BC ratio 12.5 and 13.2 for breasts for 5 and 10 yr old phantoms, respectively. For organs closest to the isocentre such as the thyroid, neutron doses were lower for BC than RS due to neutrons moderation in the target volume, but for more distant organs like bladder-conversely-lower doses for RS than BC were observed. The use of 3D printed BC as the pre-absorber placed in the near vicinity of patient in the treatment of superficial tumours does not result in the increase of secondary radiation compared to the treatment with RS, placed far from the patient.
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Affiliation(s)
- A Wochnik
- Institute of Nuclear Physics PAN, Radzikowskiego 152, Krakow 31-342, Poland
| | - L Stolarczyk
- Institute of Nuclear Physics PAN, Radzikowskiego 152, Krakow 31-342, Poland.,Skandionkliniken, von Kraemers Allé 26, Uppsala 752 37, Sweden.,Dansk Center for Partikelterapi, Palle Juul-Jensens Boulevard 25, 8200 Aarhus N, Denmark
| | - I Ambrožová
- Department of Radiation Dosimetry, Nuclear Physics Institute Czech Academy of Sciences, Prague CZ-250 68 Řež, Czech Republic
| | - M Davídková
- Department of Radiation Dosimetry, Nuclear Physics Institute Czech Academy of Sciences, Prague CZ-250 68 Řež, Czech Republic
| | - M De Saint-Hubert
- Belgium Nuclear Research Centre (SCK CEN), Boeretang 200, Mol BE-2400, Belgium
| | - S Domański
- National Centre for Nuclear Research, Otwock-Świerk 05-400, Poland
| | - C Domingo
- Departament de Física, Universitat Autònoma de Barcelona (UAB), Bellaterra E-08193, Spain
| | - Ž Knežević
- Ruđer Bošković Institute, Bijenička c. 54, Zagreb 10000, Croatia
| | - R Kopeć
- Institute of Nuclear Physics PAN, Radzikowskiego 152, Krakow 31-342, Poland
| | - M Kuć
- National Centre for Nuclear Research, Otwock-Świerk 05-400, Poland
| | - M Majer
- Ruđer Bošković Institute, Bijenička c. 54, Zagreb 10000, Croatia
| | - N Mojżeszek
- Institute of Nuclear Physics PAN, Radzikowskiego 152, Krakow 31-342, Poland
| | - V Mares
- Helmholtz Zentrum München, Institute of Radiation Medicine, Ingolstädter Landstraße 1, Neuherberg 85764, Germany
| | - I Martínez-Rovira
- Departament de Física, Universitat Autònoma de Barcelona (UAB), Bellaterra E-08193, Spain
| | - M Á Caballero-Pacheco
- Departament de Física, Universitat Autònoma de Barcelona (UAB), Bellaterra E-08193, Spain
| | - E Pyszka
- Institute of Nuclear Physics PAN, Radzikowskiego 152, Krakow 31-342, Poland
| | - J Swakoń
- Institute of Nuclear Physics PAN, Radzikowskiego 152, Krakow 31-342, Poland
| | - S Trinkl
- Helmholtz Zentrum München, Institute of Radiation Medicine, Ingolstädter Landstraße 1, Neuherberg 85764, Germany.,Technische Universität München, Physik-Department, Garching 85748, Germany
| | - M Tisi
- Helmholtz Zentrum München, Institute of Radiation Medicine, Ingolstädter Landstraße 1, Neuherberg 85764, Germany
| | - R Harrison
- University of Newcastle upon Tyne, Tyne and Wear, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - P Olko
- Institute of Nuclear Physics PAN, Radzikowskiego 152, Krakow 31-342, Poland
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15
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Proton pencil beam scanning reduces secondary cancer risk in breast cancer patients with internal mammary chain involvement compared to photon radiotherapy. Radiat Oncol 2020; 15:228. [PMID: 33008412 PMCID: PMC7532613 DOI: 10.1186/s13014-020-01671-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 09/24/2020] [Indexed: 11/21/2022] Open
Abstract
Purpose Proton pencil beam scanning (PBS) represents an interesting option for the treatment of breast cancer (BC) patients with nodal involvement. Here we compare tangential 3D-CRT and VMAT to PBS proton therapy (PT) in terms of secondary cancer risk (SCR) for the lungs and for contralateral breast. Methods Five BC patients including supraclavicular (SVC) nodes in the target (Group 1) and five including SVC plus internal-mammary-nodes (IMNs, Group 2) were considered. The Group 1 patients were planned by PT versus tangential 3D-CRT in free-breathing (FB). The Group 2 patients were planned by PT versus VMAT considering both FB and deep-inspiration breath hold (DIBH) irradiation. The prescription dose to the target volume was 50 Gy (2 Gy/fraction). A constant RBE = 1.1 was assumed for PT. The SCR was evaluated with the excess absolute risk (EAR) formalism, considering also the age dependence. A cumulative EAR was finally computed. Results According to the linear, linear-exponential and linear-plateau dose response model, the cumulative EAR for Group 1 patients after PT was equal to 45 ± 10, 17 ± 3 and 15 ± 3, respectively. The corresponding relative increase for tangential 3D-CRT was equal to a factor 2.1 ± 0.5, 2.1 ± 0.4 and 2.3 ± 0.4. Group 2 patients showed a cumulative EAR after PT in FB equal to 65 ± 3, 21 ± 1 and 20 ± 1, according to the different models; the relative risk obtained with VMAT increased by a factor 3.5 ± 0.2, 5.2 ± 0.3 and 5.1 ± 0.3. Similar values emerge from DIBH plans. Contrary to photon radiotherapy, PT appears to be not sensitive to the age dependence due to the very low delivered dose. Conclusions PBS PT is associated to significant SCR reduction in BC patients compared to photon radiotherapy. The benefits are maximized for young patients with both SVC and IMNs involvement. When combined with the improved sparing of the heart, this might contribute to the establishment of effective patient-selection criteria for proton BC treatments.
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16
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Cancer risk after breast proton therapy considering physiological and radiobiological uncertainties. Phys Med 2020; 76:1-6. [PMID: 32563956 DOI: 10.1016/j.ejmp.2020.06.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The reduced normal tissue dose burden from protons can reduce the risk of second cancer for breast cancer patients. Breathing motion and the impact of variable relative biological effectiveness (RBE) are however concerns for proton dose distributions. This study aimed to quantify the impact of these factors on risk predictions from proton and photon therapy. MATERIALS AND METHODS Twelve patients were planned in free breathing with protons and photons to deliver 50 Gy (RBE) in 25 fractions (assuming RBE = 1.1 for protons) to the left breast. Second cancer risk was evaluated with several models for the lungs, contralateral breast, heart and esophagus as organs at risk (OARs). Plans were recalculated on CT-datasets acquired in extreme phases to account for breathing motion. Proton plans were also recalculated assuming variable RBE for a range of radiobiological parameters. RESULTS The OARs received substantially lower doses from protons compared to photons. The highest risks were for the lungs (average second cancer risks of 0.31% and 0.12% from photon and proton plans, respectively). The reduced risk with protons was maintained, even when breathing and/or RBE variation were taken into account. Furthermore, while the total risks from the photon plans were seen to increase with the integral dose, no such correlation was observed for the proton plans. CONCLUSIONS Protons have an advantage over the photons with respect to the induction of cancer. Uncertainties in physiological movements and radiobiological parameters affected the absolute risk estimates, but not the general trend of lower risk associated with proton therapy.
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17
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Afkham Y, Mesbahi A, Alemi A, Zolfagharpour F, Jabbari N. Design and fabrication of a Nano-based neutron shield for fast neutrons from medical linear accelerators in radiation therapy. Radiat Oncol 2020; 15:105. [PMID: 32393290 PMCID: PMC7216519 DOI: 10.1186/s13014-020-01551-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 04/27/2020] [Indexed: 11/24/2022] Open
Abstract
Background Photo-neutrons are produced at the head of the medical linear accelerators (linac) by the interaction of high-energy photons, and patients receive a whole-body-absorbed dose from these neutrons. The current study aimed to find an efficient shielding material for fast neutrons. Methods Nanoparticles (NPs) of Fe3O4 and B4C were applied in a matrix of silicone resin to design a proper shield against fast neutrons produced by the 18 MeV photon beam of a Varian 2100 C/D linac. Neutron macroscopic cross-sections for three types of samples were calculated by the Monte Carlo (MC) method and experimentally measured for neutrons of an Am-Be source. The designed shields in different concentrations were tested by MCNPX MC code, and the proper concentration was chosen for the experimental test. A shield was designed with two layers, including nano-iron oxide and a layer of nano-boron carbide for eliminating fast neutrons. Results MC simulation results with uncertainty less than 1% showed that for discrete energies and 50% nanomaterial concentration, the macroscopic cross-sections for iron oxide and boron carbide at the energy of 1 MeV were 0.36 cm− 1 and 0.32 cm− 1, respectively. For 30% nanomaterial concentration, the calculated macroscopic cross-sections for iron oxide and boron carbide shields for Am-Be spectrum equaled 0.12 cm− 1 and 0.15 cm− 1, respectively, while they are 0.15 cm− 1 and 0.18 cm− 1 for the linac spectrum. In the experiment with the Am-Be spectrum, the macroscopic cross-sections for 30% nanomaterial concentration were 0.17 ± 0.01 cm− 1 for iron oxide and 0.21 ± 0.02 cm− 1 for boron carbide. The measured transmission factors for 30% nanomaterial concentration with the Am-Be spectrum were 0.71 ± 0.01, 0.66 ± 0.02, and 0.62 ± 0.01 for the iron oxide, boron carbide, and double-layer shields, respectively. In addition, these values were 0.74, 0.69, and 0.67, respectively, for MC simulation for the linac spectrum at the same concentration and thickness of 2 cm. Conclusion Results achieved from MC simulation and experimental tests were in a satisfactory agreement. The difference between MC and measurements was in the range of 10%. Our results demonstrated that the designed double-layer shield has a superior macroscopic cross-section compared with two single-layer nanoshields and more efficiently eliminates fast photo-neutrons.
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Affiliation(s)
- Younes Afkham
- Department of Medical Physics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Asghar Mesbahi
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Abdolali Alemi
- Department of Inorganic Chemistry, Faculty of chemistry, Tabriz University, Tabriz, Iran
| | - Farhad Zolfagharpour
- Department of Physics, Faculty of Basic Sciences, University Of Mohaghegh Ardebili, Ardabil, Iran
| | - Nasrollah Jabbari
- Solid Tumor Research Center, Cellular and Molecular Medicine Institute, Urmia University of Medical Sciences, Urmia, Iran.
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Method to quickly and accurately calculate absorbed dose from therapeutic and stray photon exposures throughout the entire body in individual patients. Med Phys 2020; 47:2254-2266. [DOI: 10.1002/mp.14018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/11/2019] [Accepted: 12/24/2019] [Indexed: 01/26/2023] Open
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Lomax AJ. Myths and realities of range uncertainty. Br J Radiol 2020; 93:20190582. [PMID: 31778317 PMCID: PMC7066970 DOI: 10.1259/bjr.20190582] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 11/01/2019] [Accepted: 11/24/2019] [Indexed: 12/25/2022] Open
Abstract
Range uncertainty is a much discussed topic in proton therapy. Although a very real aspect of proton therapy, its magnitude and consequences are sometimes misunderstood or overestimated. In this article, the sources and consequences of range uncertainty are reviewed, a number of myths associated with the effect discussed with the aim of putting range uncertainty into clinical context and attempting to de-bunk some of the more exaggerated claims made as to its consequences.
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Affiliation(s)
- Antony John Lomax
- Centre for Proton Therapy, Paul Scherrer Institute, Switzerland and Department of Physics, ETH Zurich, Switzerland
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20
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Hälg RA, Schneider U. Neutron dose and its measurement in proton therapy-current State of Knowledge. Br J Radiol 2020; 93:20190412. [PMID: 31868525 PMCID: PMC7066952 DOI: 10.1259/bjr.20190412] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 12/06/2019] [Accepted: 12/19/2019] [Indexed: 12/26/2022] Open
Abstract
Proton therapy has shown dosimetric advantages over conventional radiation therapy using photons. Although the integral dose for patients treated with proton therapy is low, concerns were raised about late effects like secondary cancer caused by dose depositions far away from the treated area. This is especially true for neutrons and therefore the stray dose contribution from neutrons in proton therapy is still being investigated. The higher biological effectiveness of neutrons compared to photons is the main cause of these concerns. The gold-standard in neutron dosimetry is measurements, but performing neutron measurements is challenging. Different approaches have been taken to overcome these difficulties, for instance with newly developed neutron detectors. Monte Carlo simulations is another common technique to assess the dose from secondary neutrons. Measurements and simulations are used to develop analytical models for fast neutron dose estimations. This article tries to summarize the developments in the different aspects of neutron dose in proton therapy since 2017. In general, low neutron doses have been reported, especially in active proton therapy. Although the published biological effectiveness of neutrons relative to photons regarding cancer induction is higher, it is unlikely that the neutron dose has a large impact on the second cancer risk of proton therapy patients.
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Novel air-to-tissue conversion factors for fast, epithermal and thermal photoneutrons in a Siemens ONCOR dual energy 18 MV X-ray medical linear accelerator. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.106138] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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König L, Bougatf N, Hörner-Rieber J, Chaudhri N, Mielke T, Klüter S, Haefner MF, Rieken S, Haberer T, Debus J, Herfarth K. Consolidative mediastinal irradiation of malignant lymphoma using active scanning proton beams: clinical outcome and dosimetric comparison. Strahlenther Onkol 2019; 195:677-687. [PMID: 30972453 DOI: 10.1007/s00066-019-01460-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 03/25/2019] [Indexed: 12/25/2022]
Abstract
PURPOSE Current research approaches in lymphoma focus on reduction of therapy-associated long-term side effects. Especially in mediastinal lymphoma, proton beam radiotherapy (PT) may be a promising approach for reducing the dose to organs at risk (OAR). PATIENTS In total, 20 patients were irradiated with active scanning PT at Heidelberg Ion Beam Therapy Center (HIT) between September 2014 and February 2017. For comparative analysis, additional photon irradiation plans with helical intensity-modulated radiotherapy (IMRT) were calculated and quantitative and qualitative dose evaluations were made for both treatment modalities. Toxicity and survival outcomes were evaluated. RESULTS Clinical target volume coverage was comparable in both treatment modalities and did not significantly differ between IMRT and PT. Nevertheless, PT showed superiority regarding the homogeneity index (HIPT = 1.041 vs. HIIMRT = 1.075, p < 0.001). For all OAR, PT showed significantly higher dose reductions compared with IMRT. In particular, the dose to the heart was reduced in PT (absolute dose reduction of Dmean of 3.3 Gy [all patients] and 4.2 Gy [patients with pericardial involvement]). Likewise, the subgroup analysis of female patients, who were expected to receive higher doses to the breast, showed a higher dose reduction in Dmean of 1.2 Gy (right side) and 2.2 Gy (left side). After a median follow-up of 32 months (range 21-48 months), local and distant progression free survival (LPFS and DPFS) were 95.5% and 95.0%, respectively. Radiotherapy was tolerated well with only mild (grade 1-2) radiation-induced acute and chronic side effects. CONCLUSION A significant reduction in the dose to the surrounding OAR was achieved with PT compared with photon irradiation, without compromising target volume coverage. Dosimetric advantages may have the potential to translate into a reduction of long-term radiation-induced toxicity in young patients with malignant lymphoma of the mediastinum.
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Affiliation(s)
- Laila König
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. .,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. .,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany.
| | - Nina Bougatf
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany
| | - Juliane Hörner-Rieber
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany
| | - Naved Chaudhri
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany
| | - Thomas Mielke
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany
| | - Sebastian Klüter
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Matthias Felix Haefner
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany
| | - Stefan Rieken
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany
| | - Thomas Haberer
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany
| | - Klaus Herfarth
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany
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23
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Speleers BA, Belosi FM, De Gersem WR, Deseyne PR, Paelinck LM, Bolsi A, Lomax AJ, Boute BG, Van Greveling AE, Monten CM, Van de Velde JJ, Vercauteren TH, Veldeman L, Weber DC, De Neve WC. Comparison of supine or prone crawl photon or proton breast and regional lymph node radiation therapy including the internal mammary chain. Sci Rep 2019; 9:4755. [PMID: 30894606 PMCID: PMC6427000 DOI: 10.1038/s41598-019-41283-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 02/22/2019] [Indexed: 12/25/2022] Open
Abstract
We report on a dosimetrical study comparing supine (S) and prone-crawl (P) position for radiotherapy of whole breast (WB) and loco-regional lymph node regions, including the internal mammary chain (LN_IM). Six left sided breast cancer patients were CT-simulated in S and P positions and four patients only in P position. Treatment plans were made using non-coplanar volumetric modulated arc photon therapy (VMAT) or pencil beam scanning intensity modulated proton therapy (IMPT). Dose prescription was 15*2.67 Gy(GyRBE). The average mean heart doses for S or P VMAT were 5.6 or 4.3 Gy, respectively (p = 0.16) and 1.02 or 1.08 GyRBE, respectively for IMPT (p = 0.8; p < 0.001 for IMPT versus VMAT). The average mean lung doses for S or P VMAT were 5.91 or 2.90 Gy, respectively (p = 0.002) and 1.56 or 1.09 GyRBE, respectively for IMPT (p = 0.016). In high-risk patients, average (range) thirty-year mortality rates from radiotherapy-related cardiac injury and lung cancer were estimated at 6.8(5.4-9.4)% or 3.8(2.8-5.1)% for S or P VMAT (p < 0.001), respectively, and 1.6(1.1-2.0)% or 1.2(0.8-1.6)% for S or P IMPT (p = 0.25), respectively. Radiation-related mortality risk could outweigh the ~8% disease-specific survival benefit of WB + LN_IM radiotherapy for S VMAT but not P VMAT. IMPT carries the lowest radiation-related mortality risks.
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Affiliation(s)
- Bruno A Speleers
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | | | - Werner R De Gersem
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Pieter R Deseyne
- Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | - Leen M Paelinck
- Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | | | | | - Bert G Boute
- Industrial Design Center, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | | | - Christel M Monten
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.,Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | - Joris J Van de Velde
- Department of Anatomy, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Tom H Vercauteren
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.,Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | - Liv Veldeman
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.,Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium
| | - Damien C Weber
- Paul Scherrer Institut, Villigen, Switzerland.,Radiation Oncology Department, University Hospital of Bern, Bern, Switzerland
| | - Wilfried C De Neve
- Department of Radiotherapy and Experimental Cancer Research, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium. .,Department of Radiation Oncology, Ghent University Hospital, Ghent, Belgium.
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25
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Hauri P, Schneider U. Whole-body dose equivalent including neutrons is similar for 6 MV and 15 MV IMRT, VMAT, and 3D conformal radiotherapy. J Appl Clin Med Phys 2019; 20:56-70. [PMID: 30791198 PMCID: PMC6414138 DOI: 10.1002/acm2.12543] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/08/2018] [Accepted: 12/31/2018] [Indexed: 12/24/2022] Open
Abstract
PURPOSE This study investigates the difference in whole-body dose equivalent between 6 and 15 MV image-guided radiotherapy (IGRT) for the treatment of a rhabdomyosarcoma in the prostate. METHODS A previously developed model for stray radiation of the primary beam was improved and used to calculate the photon dose and photon energy in the out-of-field region for a radiotherapy patient. The dose calculated by the treatment planning system was fused with the model-calculated out-of-field dose, resulting in a whole-body photon dose distribution. The peripheral neutron dose equivalent was calculated using an analytical model from the literature. A daily cone beam CT dose was added to the neutron and photon dose equivalents. The calculated 3D dose distributions were compared to independent measurements conducted with thermoluminescence dosimeters and an anthropomorphic phantom. The dose contributions from the IGRT treatments of three different techniques applied with two nominal X-ray energies were compared using dose equivalent volume histograms (DEVHs). RESULTS The calculated and measured out-of-field whole-body dose equivalents for the IGRT treatments agreed within (9 ± 10) % (mean and type A SD). The neutron dose equivalent was a minor contribution to the total out-of-field dose up to 50 cm from the isocenter. Further from the isocenter, head leakage was dominating inside the patient body, whereas the neutron dose equivalent contribution was important close to the surface. There were small differences between the whole-body DEVHs of the 6 and 15 MV treatments applied with the same technique, although the single scatter contributions showed large differences. Independent of the beam energy, the out-of-field dose of the volumetric-modulated arc therapy (VMAT) treatment was significantly lower than the dynamic intensity-modulated radiation therapy (IMRT) treatment. CONCLUSION The calculated whole-body dose helped to understand the importance of the dose contributions in different areas of the patient. Regarding radiation protection of the patient for IGRT treatments, the choice of beam energy is not important, whereas the treatment technique has a large influence on the out-of-field dose. If the patient is treated with intensity-modulated beams, VMAT should be used instead of dynamic IMRT in terms of radiation protection of the patient. In general, the developed models for photon and neutron dose equivalent calculation can be used for any patient geometry, tumor location, and linear accelerator.
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Affiliation(s)
- Pascal Hauri
- Department of PhysicsUniversity of ZurichZurichSwitzerland
- Radiotherapy HirslandenHirslanden Medical CenterAarauSwitzerland
| | - Uwe Schneider
- Department of PhysicsUniversity of ZurichZurichSwitzerland
- Radiotherapy HirslandenHirslanden Medical CenterAarauSwitzerland
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26
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Patterns of proton therapy use in pediatric cancer management in 2016: An international survey. Radiother Oncol 2019; 132:155-161. [DOI: 10.1016/j.radonc.2018.10.022] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/10/2018] [Accepted: 10/22/2018] [Indexed: 01/19/2023]
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27
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Cosset JM, Nassef M, Saïdi R, Pugnaire J, Ben Abdennebi A, Noël A. [Which photon energy for intensity-modulated radiotherapy and volumetric-modulated arctherapy in 2019?]. Cancer Radiother 2018; 23:58-61. [PMID: 30551930 DOI: 10.1016/j.canrad.2018.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/14/2018] [Accepted: 04/17/2018] [Indexed: 01/02/2023]
Abstract
For more than a decade, the majority of radiation oncology centres have been delivering intensity-modulated radiotherapy (then volumetric-modulated arctherapy) with 6 MV photons as their standard of care. This « dogma » had been supported by the usual absence of dosimetric advantages with high-energy photons (15 to 18 MV or more), at least for the planning target volume and the dose received by the adjacent organs at risk, and by the neutron component as soon as the photon energy exceeds 10 MV. Recent data could question such a dogma. First, in 2019, one cannot avoid taking into account the integral dose, delivered outside the treated volume. Actually, most available data show that integral dose is higher with low energy photons (as 6 MV) than with higher energies. Moreover, recent studies have shown that the neutron component at high energies may have been overestimated in the past; in fact, the neutron dose appears to be lower, and sometimes much lower, than the dose we accept for imaging. Finally, a few cohort studies did not show any increase in second cancers incidence after high-energy photon radiotherapy. In such a context, the American Association of Physicists in Medicine (AAPM) TG 158 document, released a few months ago, clearly states that there is a trade-off between high- and low-energy treatments. High-energy therapy is associated with neutron production, while low-energy therapy results in higher stray photon dose. According to the AAPM, « the optimal energy is likely an intermediate such as 10 MV ».
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Affiliation(s)
- J-M Cosset
- GIE Charlebourg, Amethyst group, 65, avenue Foch, 92250 La Garenne-Colombes, France.
| | - M Nassef
- GIE Charlebourg, Amethyst group, 65, avenue Foch, 92250 La Garenne-Colombes, France
| | - R Saïdi
- GIE Charlebourg, Amethyst group, 65, avenue Foch, 92250 La Garenne-Colombes, France
| | - J Pugnaire
- GIE Charlebourg, Amethyst group, 65, avenue Foch, 92250 La Garenne-Colombes, France
| | - A Ben Abdennebi
- CNS CROM Compiègne, Amethyst group, 3, rue Jean-Jacques-Bernard, 60200 Compiègne, France
| | - A Noël
- Campus Sciences, centre de recherche en automatique de Nancy (Cran), BP 70239, 54506 Vandœuvre-lès-Nancy cedex, France; Campus Sciences, université de Lorraine, UMR 7039, BP 70239, 54506 Vandœuvre-lès-Nancy cedex, France; CNRS, UMR7039, Campus Sciences, BP 70239, 54506 Vandœuvre-lès-Nancy cedex, France
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28
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Ardenfors O, Dasu A, Lillhök J, Persson L, Gudowska I. Out-of-field doses from secondary radiation produced in proton therapy and the associated risk of radiation-induced cancer from a brain tumor treatment. Phys Med 2018; 53:129-136. [DOI: 10.1016/j.ejmp.2018.08.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/27/2018] [Accepted: 08/30/2018] [Indexed: 02/07/2023] Open
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Ardenfors O, Gudowska I, Flejmer AM, Dasu A. Impact of irradiation setup in proton spot scanning brain therapy on organ doses from secondary radiation. RADIATION PROTECTION DOSIMETRY 2018; 180:261-266. [PMID: 30085315 DOI: 10.1093/rpd/ncy013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 01/16/2018] [Indexed: 06/08/2023]
Abstract
A Monte Carlo model of a proton spot scanning pencil beam was used to simulate organ doses from secondary radiation produced from brain tumour treatments delivered with either a lateral field or a vertex field to one adult and one paediatric patient. Absorbed doses from secondary neutrons, photons and protons and neutron equivalent doses were higher for the vertex field in both patients, but the differences were low in absolute terms. Absorbed doses ranged between 0.1 and 43 μGy.Gy-1 in both patients with the paediatric patient receiving higher doses. The neutron equivalent doses to the organs ranged between 0.5 and 141 μSv.Gy-1 for the paediatric patient and between 0.2 and 134 μSv.Gy-1 for the adult. The highest neutron equivalent dose from the entire treatment was 7 mSv regardless of field setup and patient size. The results indicate that different field setups do not introduce large absolute variations in out-of-field doses produced in patients undergoing proton pencil beam scanning of centrally located brain tumours.
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Affiliation(s)
- Oscar Ardenfors
- Medical Radiation Physics, Department of Physics, Stockholm University, Box 260, Stockholm, Sweden
| | - Irena Gudowska
- Medical Radiation Physics, Department of Physics, Stockholm University, Box 260, Stockholm, Sweden
| | - Anna Maria Flejmer
- Department of Oncology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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30
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Stolarczyk L, Trinkl S, Romero-Expósito M, Mojżeszek N, Ambrozova I, Domingo C, Davídková M, Farah J, Kłodowska M, Knežević Ž, Liszka M, Majer M, Miljanić S, Ploc O, Schwarz M, Harrison RM, Olko P. Dose distribution of secondary radiation in a water phantom for a proton pencil beam-EURADOS WG9 intercomparison exercise. Phys Med Biol 2018; 63:085017. [PMID: 29509148 DOI: 10.1088/1361-6560/aab469] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Systematic 3D mapping of out-of-field doses induced by a therapeutic proton pencil scanning beam in a 300 × 300 × 600 mm3 water phantom was performed using a set of thermoluminescence detectors (TLDs): MTS-7 (7LiF:Mg,Ti), MTS-6 (6LiF:Mg,Ti), MTS-N (natLiF:Mg,Ti) and TLD-700 (7LiF:Mg,Ti), radiophotoluminescent (RPL) detectors GD-352M and GD-302M, and polyallyldiglycol carbonate (PADC)-based (C12H18O7) track-etched detectors. Neutron and gamma-ray doses, as well as linear energy transfer distributions, were experimentally determined at 200 points within the phantom. In parallel, the Geant4 Monte Carlo code was applied to calculate neutron and gamma radiation spectra at the position of each detector. For the cubic proton target volume of 100 × 100 × 100 mm3 (spread out Bragg peak with a modulation of 100 mm) the scattered photon doses along the main axis of the phantom perpendicular to the primary beam were approximately 0.5 mGy Gy-1 at a distance of 100 mm and 0.02 mGy Gy-1 at 300 mm from the center of the target. For the neutrons, the corresponding values of dose equivalent were found to be ~0.7 and ~0.06 mSv Gy-1, respectively. The measured neutron doses were comparable with the out-of-field neutron doses from a similar experiment with 20 MV x-rays, whereas photon doses for the scanning proton beam were up to three orders of magnitude lower.
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Affiliation(s)
- L Stolarczyk
- Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow, Poland. Skandionkliniken, von Kraemers Allé 26, 752 37 Uppsala, Sweden. Author to whom any correspondence should be addressed
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31
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Trott KR. Special radiobiological features of second cancer risk after particle radiotherapy. Phys Med 2017; 42:221-227. [PMID: 29103987 DOI: 10.1016/j.ejmp.2017.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 04/18/2017] [Accepted: 05/01/2017] [Indexed: 11/24/2022] Open
Abstract
In absolute terms: second cancer risks from radiotherapy of first cancers in adults are small compared to the benefits from radiotherapy but this is not so for radiotherapy of childhood cancers. Moreover, the radiation dose dependence of cancer induction differs between organs and tissues. The organ-specific dose dependence of second cancer risks may indicate the existence of different radiobiological mechanisms. As an inevitable consequence of the age dependence of organ sensitivity to second cancer induction, the organ/tissue weighting factors which have been proposed by ICRP for calculating effective dose (the dose unit Sv) and for risk estimation in the general population should not be used in medical radiation exposures. In adult cancer radiotherapy, the most common unwanted effect is local tumour recurrence whereas both, severe late normal tissue damage and radiation-induced second cancers are rare, around 1% of locally controlled cancer patients. In childhood cancers, local failures are rare (<10% in some cancers) yet second cancers are more common than uncontrolled primaries. The main reason for considering particle radiotherapy for childhood cancers is the possibility to exploit their physical characteristics to reduce the radiation exposure to organs and tissues close to and distant from the primary cancer which is to be targeted. However, the relative biological effectiveness of the radiation doses within the proton beam is not a constant and the relative biological effectiveness of the neutrons is not known as far as the mechanisms of late normal tissue damage and second cancer risk are concerned. In view of the highly charged discussions of the potential risks of treatment-induced seecond cancers from the neutron contamination of exposure doses in out-of-PTV critical organs a comprehensive European project called ANDANTE was performed which integrated the disciplines of radiation physics, molecular biology, systems biology modelling and epidemiology in order to investigate the RBE of induction of cancer from exposure to neutrons compared to photons. Since out-of-field "effective" neutron doses from proton therapy are smaller than the photon stray doses whichever reasonable RBE is chosen for comparison, and since the absolute risk of radiation-induced second cancer rates are in the order of 1% in the cohorts of adult patients who have been treated in the past with methods which caused relatively high out-of-field doses to large body volumes, it is highly unlikely that such patients treated in future with highly conformal particle therapy are at a higher radiation-induced second cancer risk than those patients treated with photons and described before. Still, the potential risks of second cancers from scattered proton radiotherapy for childhood cancers may cause concern. Yet, the overall risk of undesired consequences of radiation exposure of children which are more complex and manifold than in adult patients (including developmental, neurocognitive, hormonal and growth impairment effects) are likely to be very much reduced by the better focussing of the radiation dose in the target offered by particle radioherapy. This benefit may far outweigh the still hypothetical second cancer risk from particle radiotherapy in pediatric radiotherapy.
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Kry SF, Bednarz B, Howell RM, Dauer L, Followill D, Klein E, Paganetti H, Wang B, Wuu CS, George Xu X. AAPM TG 158: Measurement and calculation of doses outside the treated volume from external-beam radiation therapy. Med Phys 2017; 44:e391-e429. [DOI: 10.1002/mp.12462] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 05/17/2017] [Accepted: 05/25/2017] [Indexed: 12/14/2022] Open
Affiliation(s)
- Stephen F. Kry
- Department of Radiation Physics; MD Anderson Cancer Center; Houston TX 77054 USA
| | - Bryan Bednarz
- Department of Medical Physics; University of Wisconsin; Madison WI 53705 USA
| | - Rebecca M. Howell
- Department of Radiation Physics; MD Anderson Cancer Center; Houston TX 77054 USA
| | - Larry Dauer
- Departments of Medical Physics/Radiology; Memorial Sloan-Kettering Cancer Center; New York NY 10065 USA
| | - David Followill
- Department of Radiation Physics; MD Anderson Cancer Center; Houston TX 77054 USA
| | - Eric Klein
- Department of Radiation Oncology; Washington University; Saint Louis MO 63110 USA
| | - Harald Paganetti
- Department of Radiation Oncology; Massachusetts General Hospital and Harvard Medical School; Boston MA 02114 USA
| | - Brian Wang
- Department of Radiation Oncology; University of Louisville; Louisville KY 40202 USA
| | - Cheng-Shie Wuu
- Department of Radiation Oncology; Columbia University; New York NY 10032 USA
| | - X. George Xu
- Department of Mechanical, Aerospace, and Nuclear Engineering; Rensselaer Polytechnic Institute; Troy NY 12180 USA
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Badiyan SN, Ulmer S, Ahlhelm FJ, Fredh ASM, Kliebsch U, Calaminus G, Bolsi A, Albertini F, Leiser D, Timmermann B, Malyapa RS, Schneider R, Lomax AJ, Weber DC. Clinical and Radiologic Outcomes in Adults and Children Treated with Pencil-Beam Scanning Proton Therapy for Low-Grade Glioma. Int J Part Ther 2017; 3:450-460. [PMID: 31772995 PMCID: PMC6871558 DOI: 10.14338/ijpt-16-00031.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 03/29/2017] [Indexed: 09/21/2023] Open
Abstract
PURPOSE We assessed clinical and radiologic outcomes in adults and children with low-grade glioma (LGG) of the brain treated with pencil-beam scanning (PBS) proton therapy (PT). MATERIALS AND METHODS Between 1997 and 2014, 28 patients were treated with PBS PT, 20 (71%) of whom were younger than 18 years. Median age at start of PT was 12.3 years (range, 2.2-53.0 years). Nine patients (32%) underwent at least a subtotal resection; 12 (43%) underwent biopsy; and 7 (25%) were diagnosed radiographically. Twelve patients (43%) had grade II and 9 (32%) had grade I gliomas. Eleven patients (39%) received chemotherapy before PT. A median dose of 54 Gy (relative biologic effectiveness) was administered. Radiologic response to PT was determined using the Response Evaluation Criteria in Solid Tumors (RECIST). Eight domains of quality of life (QoL) for 16 pediatric patients were assessed prospectively by patients' parents using the pediatric QoL proxy questionnaire. Progression-free survival and overall survival (OS) were estimated by the Kaplan-Meier method. Median follow-up was 42.1 months for living patients. RESULTS Ten patients (36%) developed local, clinical failure. Three patients (11%) died, all of tumor progression. Radiographic tumor response by RECIST was evaluable in 11 patients: 9 (82%) with stable disease, 1 (9%) with partial response, and 1 (9%) with complete response to PT. Three-year OS and progression-free survival were 83.4% and 56.0%, respectively. No ≥ grade III acute toxicities were observed. Grade III, late radiation necrosis developed in 1 patient (4%). No appreciable change in pediatric QoL proxy scores in children was noted in any of the 8 domains at any time point. CONCLUSION Treatment with PBS PT is effective for LGG, with minimal acute toxicity and, in children, no appreciable decline in QoL. More patients and longer follow-up are needed to determine the long-term efficacy and toxicity of PT for LGG.
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Affiliation(s)
- Shahed N. Badiyan
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Frank J. Ahlhelm
- Department of Radiology, Cantonal Hospital Baden, Baden, Switzerland
| | - Anna S. M. Fredh
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Ulrike Kliebsch
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Gabriele Calaminus
- Department of Pediatric Hematology and Oncology, University Hospital Münster, Münster, Germany
| | - Alessandra Bolsi
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | | | | | - Beate Timmermann
- Clinic for Particle Therapy, West German Proton Center, University Hospital Essen, Germany
| | - Robert S. Malyapa
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Ralf Schneider
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - Antony J. Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, Swiss Institute of Technology, Zurich, Switzerland
| | - Damien C. Weber
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
- Department of Radiation Oncology, University Hospital Zürich, Zürich, Switzerland
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Measurement of stray neutron doses inside the treatment room from a proton pencil beam scanning system. Phys Med 2017; 34:80-84. [DOI: 10.1016/j.ejmp.2017.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 01/09/2017] [Accepted: 01/18/2017] [Indexed: 11/18/2022] Open
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Romero-Expósito M, Domingo C, Sánchez-Doblado F, Ortega-Gelabert O, Gallego S. Experimental evaluation of neutron dose in radiotherapy patients: Which dose? Med Phys 2016; 43:360. [PMID: 26745929 DOI: 10.1118/1.4938578] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The evaluation of peripheral dose has become a relevant issue recently, in particular, the contribution of secondary neutrons. However, after the revision of the Recommendations of the International Commission on Radiological Protection, there has been a lack of experimental procedure for its evaluation. Specifically, the problem comes from the replacement of organ dose equivalent by the organ-equivalent dose, being the latter "immeasurable" by definition. Therefore, dose equivalent has to be still used although it needs the calculation of the radiation quality factor Q, which depends on the unrestricted linear energy transfer, for the specific neutron irradiation conditions. On the other hand, equivalent dose is computed through the radiation weighting factor wR, which can be easily calculated using the continuous function provided by the recommendations. The aim of the paper is to compare the dose equivalent evaluated following the definition, that is, using Q, with the values obtained by replacing the quality factor with wR. METHODS Dose equivalents were estimated in selected points inside a phantom. Two types of medical environments were chosen for the irradiations: a photon- and a proton-therapy facility. For the estimation of dose equivalent, a poly-allyl-diglicol-carbonate-based neutron dosimeter was used for neutron fluence measurements and, additionally, Monte Carlo simulations were performed to obtain the energy spectrum of the fluence in each point. RESULTS The main contribution to dose equivalent comes from neutrons with energy higher than 0.1 MeV, even when they represent the smallest contribution in fluence. For this range of energy, the radiation quality factor and the radiation weighting factor are approximately equal. Then, dose equivalents evaluated using both factors are compatible, with differences below 12%. CONCLUSIONS Quality factor can be replaced by the radiation weighting factor in the evaluation of dose equivalent in radiotherapy environments simplifying the practical procedure.
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Affiliation(s)
- M Romero-Expósito
- Grup de Recerca en Radiacions Ionizants (GRRI), Departament de Física, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - C Domingo
- Grup de Recerca en Radiacions Ionizants (GRRI), Departament de Física, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - F Sánchez-Doblado
- Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Sevilla 41009, SpainServicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla 41009, Spain
| | - O Ortega-Gelabert
- Grup de Recerca en Radiacions Ionizants (GRRI), Departament de Física, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
| | - S Gallego
- Grup de Recerca en Radiacions Ionizants (GRRI), Departament de Física, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain
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Cosset JM, Chargari C, Demoor C, Giraud P, Helfre S, Mornex F, Mazal A. [Prevention of radio-induced cancers]. Cancer Radiother 2016; 20 Suppl:S61-8. [PMID: 27523416 DOI: 10.1016/j.canrad.2016.07.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The article deals with the prevention of cancers only directly related to therapeutic radiation which are distinguished from "secondary cancer". The consideration of the risk of radiation-induced cancers after radiation therapy, although it is fortunately rare events, has become indispensable today. With a review of the literature, are detailed the various involved parameters. The age of the irradiated patient is one of the main parameters. The impact of the dose is also discussed based on the model used, and based on clinical data. Other parameters defining a radiation treatment are discussed one after the other: field with the example of Hodgkin's disease, the type of radiation and the participation of secondary neutrons, spreading and splitting. All these parameters are discussed according to each organ whose sensitivity is different. The article concludes with a list of recommendations to reduce the risk of radio-induced cancers. Even with the advent of conformal radiotherapy, intensity modulation, the modulated volume arctherapy, and the development of specific machinery for the extra-cranial stereotactic, the radiation therapist must consider this risk and use of reasonable and justified control imaging. Although they constitute a small percentage of cancers that occur secondarily after a first malignant tumor, radiation-induced cancers, can not and must not be concealed or ignored and justify regular monitoring over the long term, precisely adapted on the described parameters.
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Affiliation(s)
- J-M Cosset
- Département d'oncologie/radiothérapie, institut Curie, 26, rue d'Ulm, 75005 Paris, France.
| | - C Chargari
- Service de curiethérapie, institut Gustave-Roussy, 114, rue Édouard-Vaillant, 94800 Villejuif, France; Institut de recherche biomédicale des armées, 91223 Brétigny-sur-Orge, France
| | - C Demoor
- Département de radiothérapie, institut de cancérologie de l'Ouest, boulevard J.-Monod, 44800 Saint-Herblain, Nantes, France; Unité Inserm 1018, 114, rue Édouard-Vaillant, 94805 Villejuif, France
| | - P Giraud
- Hôpital européen Georges-Pompidou, université Paris-Descartes, Paris-Cité Sorbonne, 20, rue Leblanc, 75015 Paris, France
| | - S Helfre
- Département d'oncologie/radiothérapie, institut Curie, 26, rue d'Ulm, 75005 Paris, France
| | - F Mornex
- Département d'oncologie radiothérapie, centre hospitalier Lyon-Sud, 165, chemin du Grand-Revoyet, 69310 Pierre-Bénite, Lyon, France
| | - A Mazal
- Département d'oncologie/radiothérapie, institut Curie, 26, rue d'Ulm, 75005 Paris, France
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37
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Kron T, Lehmann J, Greer PB. Dosimetry of ionising radiation in modern radiation oncology. Phys Med Biol 2016; 61:R167-205. [DOI: 10.1088/0031-9155/61/14/r167] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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38
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Schneider U, Hälg R. The Impact of Neutrons in Clinical Proton Therapy. Front Oncol 2015; 5:235. [PMID: 26557501 PMCID: PMC4617104 DOI: 10.3389/fonc.2015.00235] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 10/06/2015] [Indexed: 11/13/2022] Open
Abstract
In proton therapy, high-energy proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long-term health of cancer patients. Due to the high biological effectiveness of neutrons with regard to cancer induction, small neutron doses can be important. Published comparisons of neutron dose measurements and the corresponding estimates of cancer risk between different treatment modalities differ over orders of magnitude. In this report, the controversy about the impact of the neutron dose in proton therapy is critically discussed and viewed in the light of new epidemiological studies. In summary, the impact of neutron dose on cancer risk can be determined correctly only if the dose distributions are carefully measured or computed. It is important to include not only the neutron component into comparisons but also the complete deposition of energy as precisely as possible. Cancer risk comparisons between different radiation qualities, treatment machines, and techniques have to be performed under similar conditions. It seems that in the past, the uncertainty in the models which lead from dose to risk were overestimated when compared with erroneous dose comparisons. Current risk models used with carefully obtained dose distributions predict a second cancer risk reduction for active protons vs. photons and a more or less constant risk of passive protons vs. photons. Those findings are in general agreement with newly obtained epidemiologically results.
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Affiliation(s)
- Uwe Schneider
- Institute of Physics, Science Faculty, University of Zürich, Zürich, Switzerland
- Radiotherapy Hirslanden, Zürich, Switzerland
| | - Roger Hälg
- Institute of Physics, Science Faculty, University of Zürich, Zürich, Switzerland
- Radiotherapy Hirslanden, Zürich, Switzerland
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Toltz A, Shin N, Mitrou E, Laude C, Freeman CR, Seuntjens J, Parker W, Roberge D. Late radiation toxicity in Hodgkin lymphoma patients: proton therapy's potential. J Appl Clin Med Phys 2015; 16:167–178. [PMID: 26699298 PMCID: PMC5690189 DOI: 10.1120/jacmp.v16i5.5386] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 05/20/2015] [Accepted: 05/03/2015] [Indexed: 12/22/2022] Open
Abstract
In 2010, all young patients treated for intrathoracic Hodgkin lymphoma (HL) at one of 10 radiotherapy centers in the province of Quebec received 3D conformal photon therapy. These patients may now be at risk for late effects of their treatment, notably secondary malignancies and cardiac toxicity. We hypothesized that more complex radiotherapy, including intensity‐modulated proton therapy (IMPT) and possibly IMRT (in the form of helical tomotherapy (HT)), could benefit these patients. With institutional review board approval at 10 institutions, all treatment plans for patients under the age of 30 treated for HL during a six‐month consecutive period of 2010 were retrieved. Twenty‐six patients were identified, and after excluding patients with extrathoracic radiation or treatment of recurrence, 20 patients were replanned for HT and IMPT. Neutron dose for IMPT plans was estimated from published measurements. The relative seriality model was used to predict excess risk of cardiac mortality. A modified linear quadratic model was used to predict the excess absolute risk for induction of lung cancer and, in female patients, breast cancer. Model parameters were derived from published data. Predicted risk for cardiac mortality was similar among the three treatment techniques (absolute excess risk of cardiac mortality was not reduced for HT or IMPT (p>0.05,p>0.05) as compared to 3D CRT). Predicted risks were increased for HT and reduced for IMPT for secondary lung cancer (p<0.001,p<0.001) and breast cancers (p<0.001,p<0.001) as compared to 3D CRT. PACS numbers: 87.55.dh, 87.55.dk
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Weber DC, Badiyan S, Malyapa R, Albertini F, Bolsi A, Lomax AJ, Schneider R. Long-term outcomes and prognostic factors of skull-base chondrosarcoma patients treated with pencil-beam scanning proton therapy at the Paul Scherrer Institute. Neuro Oncol 2015; 18:236-43. [PMID: 26323608 DOI: 10.1093/neuonc/nov154] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 07/13/2015] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Skull-base chondrosarcoma (ChSa) is a rare disease, and the prognostication of this disease entity is ill defined. METHODS We assessed the long-term local control (LC) results, overall survival (OS), and prognostic factors of skull-base ChSa patients treated with pencil beam scanning proton therapy (PBS PT). Seventy-seven (male, 35; 46%) patients with histologically confirmed ChSa were treated at the Paul Scherrer Institute. Median age was 38.9 years (range, 10.2-70.0y). Median delivered dose was 70.0 GyRBE (range, 64.0-76.0 GyRBE). LC, OS, and toxicity-free survival (TFS) rates were calculated using the Kaplan Meier method. RESULTS After a mean follow-up of 69.2 months (range, 4.6-190.8 mo), 6 local (7.8%) failures were observed, 2 of which were late failures. Five (6.5%) patients died. The actuarial 8-year LC and OS were 89.7% and 93.5%, respectively. Tumor volume > 25 cm(3) (P = .02), brainstem/optic apparatus compression at the time of PT (P = .04) and age >30 years (P = .08) were associated with lower rates of LC. High-grade (≥3) radiation-induced toxicity was observed in 6 (7.8%) patients. The 8-year high-grade TFS was 90.8%. A higher rate of high-grade toxicity was observed for older patients (P = .073), those with larger tumor volume (P = .069), and those treated with 5 weekly fractions (P = .069). CONCLUSIONS This is the largest PT series reporting the outcome of patients with low-grade ChSa of the skull base treated with PBS only. Our data indicate that protons are both safe and effective. Tumor volume, brainstem/optic apparatus compression, and age were prognosticators of local failures.
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Affiliation(s)
- Damien C Weber
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland (D.C.W., S.B., R.M., F.A., A.B., A.J.L, R.S.); University of Bern, Bern, Switxerland (D.C.W.); University of Zürich, Zürich, Switzerland (D.C.W.); Department of Physics, ETH, Zürich, Switzerland (A.J.L.)
| | - Shahed Badiyan
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland (D.C.W., S.B., R.M., F.A., A.B., A.J.L, R.S.); University of Bern, Bern, Switxerland (D.C.W.); University of Zürich, Zürich, Switzerland (D.C.W.); Department of Physics, ETH, Zürich, Switzerland (A.J.L.)
| | - Robert Malyapa
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland (D.C.W., S.B., R.M., F.A., A.B., A.J.L, R.S.); University of Bern, Bern, Switxerland (D.C.W.); University of Zürich, Zürich, Switzerland (D.C.W.); Department of Physics, ETH, Zürich, Switzerland (A.J.L.)
| | - Francesca Albertini
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland (D.C.W., S.B., R.M., F.A., A.B., A.J.L, R.S.); University of Bern, Bern, Switxerland (D.C.W.); University of Zürich, Zürich, Switzerland (D.C.W.); Department of Physics, ETH, Zürich, Switzerland (A.J.L.)
| | - Alessandra Bolsi
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland (D.C.W., S.B., R.M., F.A., A.B., A.J.L, R.S.); University of Bern, Bern, Switxerland (D.C.W.); University of Zürich, Zürich, Switzerland (D.C.W.); Department of Physics, ETH, Zürich, Switzerland (A.J.L.)
| | - Antony J Lomax
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland (D.C.W., S.B., R.M., F.A., A.B., A.J.L, R.S.); University of Bern, Bern, Switxerland (D.C.W.); University of Zürich, Zürich, Switzerland (D.C.W.); Department of Physics, ETH, Zürich, Switzerland (A.J.L.)
| | - Ralf Schneider
- Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland (D.C.W., S.B., R.M., F.A., A.B., A.J.L, R.S.); University of Bern, Bern, Switxerland (D.C.W.); University of Zürich, Zürich, Switzerland (D.C.W.); Department of Physics, ETH, Zürich, Switzerland (A.J.L.)
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