1
|
Espinosa-Rodriguez A, Villa-Abaunza A, Díaz N, Pérez-Díaz M, Sánchez-Parcerisa D, Udías J, Ibáñez P. Design of an X-ray irradiator based on a standard imaging X-ray tube with FLASH dose-rate capabilities for preclinical research. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2023.110760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
2
|
Cellular Damage in the Target and Out-Of-Field Peripheral Organs during VMAT SBRT Prostate Radiotherapy: An In Vitro Phantom-Based Study. Cancers (Basel) 2022; 14:cancers14112712. [PMID: 35681692 PMCID: PMC9179488 DOI: 10.3390/cancers14112712] [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: 03/25/2022] [Revised: 05/18/2022] [Accepted: 05/27/2022] [Indexed: 02/01/2023] Open
Abstract
Simple Summary New developments show that patients with prostate cancer can benefit from radiotherapy delivered with a hypo-fractionated regimen. The aim of our study was to investigate the effect of hypo-fractionated stereotactic body radiation therapy (SBRT) of prostate cancer on out-of-field organs. We used a humanoid phantom to irradiate prostate cells in conditions similar to patient therapy, using SBRT planning. Our results show that radiation doses in the location of the intestine and lung resulted in significantly higher radiation doses than the further locations. We observed a high radiotoxic effect in the cells irradiated in the prostate, and a small increase in DNA damage and cell killing in the intestine location. Gene expression analysis revealed significant enrichment of the biological processes related to the radiation response in the prostate. In the lung and thyroid, the enrichment of several gene groups was revealed, however the processes were not clearly related to the response to radiation. Our study provides extensive data on out-of-field safety of prostate SBRT. Abstract Hypo-fractionated stereotactic body radiation therapy (SBRT) is an effective treatment for prostate cancer (PCa). Although many studies have investigated the effects of SBRT on the prostate and adjacent organs, little is known about the effects further out-of-field. The aim of this study was to investigate, both in vitro and in a quasi-humanoid phantom, the biological effects (using a dose-scaling approach) of radiation in the out-of-field peripheral organs delivered by 6 MV volumetric modulated arc therapy (VMAT) SBRT in a prostate cancer model. Healthy prostate cells were irradiated in a phantom at locations corresponding to the prostate, intestine, lung, thyroid, and brain. Seven 10 Gy fractions of VMAT SBRT were delivered to the target in a single session without intermission (scaled-up method). Radiochromic films were used to measure the doses. The radiobiological response was assessed by measuring DNA breaks, the cell survival fraction, and differences in gene expression profile. Our results showed a strong, multiparametric radiobiological response of the cells in the prostate. Outside of the radiation field, the highest doses were observed in the intestine and lung. A small increase (not statistically significant) in DNA damage and cell death was observed in the intestines. Several gene groups (cell cycle, DNA replication) were depleted in the lung and thyroid (DNA replication, endocytosis), but further analysis revealed no changes in the relevant biological processes. This study provides extensive evidence of the types and extent of radiobiological responses during VMAT SBRT in a prostate cancer model. Additional research is needed to determine whether the radiobiological effects observed in the peripheral organs are validated in a clinical context.
Collapse
|
3
|
Choi HJ, Park H, Yi CY, Kim BC, Shin WG, Min CH. Determining the energy spectrum of clinical linear accelerator using an optimized photon beam transmission protocol. Med Phys 2019; 46:3285-3297. [PMID: 31055830 DOI: 10.1002/mp.13569] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 04/09/2019] [Accepted: 04/25/2019] [Indexed: 12/29/2022] Open
Abstract
PURPOSE The complex beam delivery techniques for patient treatment using a clinical linear accelerator (linac) may result in variations in the photon spectra, which can lead to dosimetric differences in patients that cannot be accounted for by current treatment planning systems (TPSs). Therefore, precise knowledge of the fluence and energy spectrum (ES) of the therapeutic beam is very important. However, owing to the high energy and flux of the beam, the ES cannot be measured directly, and validation of the spectrum modeled in the TPS is difficult. The aim of this study is to develop an efficient beam transmission measurement procedure for accurately reconstructing the ES of a therapeutic x-ray beam generated by a clinical linac. METHODS The attenuation of a 6 MV photon beam from an Elekta Synergy Platform clinical linac through different thicknesses of graphite and lead was measured using an ion chamber. The response of the ion chamber as a function of photon energy was obtained using the Monte Carlo (MC) method in the Geant4 simulation code. Using the curves obtained in the photon beam transmission measurements and the ion chamber energy response, the ES was reconstructed using an iterative algorithm based on a mathematical model of the spectrum. To evaluate the accuracy of the spectrum reconstruction method, the reconstructed ES (ESrecon ) was compared to that determined by the MC simulation (ESMC ). RESULTS The ion chamber model in the Geant4 simulation was well validated by comparing the ion chamber perturbation factors determined by the TRS-398 calibration protocol and EGSnrc; the differences were within 0.57%. The number of transmission measurements was optimized to 10 for efficient spectrum reconstruction according to the rate of increase in the spectrum reconstruction accuracy. The distribution of ESrecon obtained using the measured transmission curves was clearly similar to the reference, ESMC , and the dose distributions in water calculated using ESrecon and ESMC were similar within a 2% local difference. However, in a heterogeneous medium, the dose discrepancy between them was >5% when a complex beam delivery technique composed of 171 control points was used. CONCLUSIONS The proposed measurement procedure required a total time of approximately 1 h to obtain and analyze 20 transmission measurements. In addition, it was confirmed that the transmission curve of high-Z materials influences the accuracy of spectrum reconstruction more than that of low-Z materials. A well-designed transmission measurement protocol suitable for clinical environments could be an essential tool for better dosimetric accuracy in patient treatment and for periodic verification of the beam quality.
Collapse
Affiliation(s)
- Hyun Joon Choi
- Department of Radiation Convergence Engineering, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju, 26493, Korea
| | - Hyojun Park
- Department of Radiation Convergence Engineering, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju, 26493, Korea
| | - Chul Young Yi
- Center for Ionizing Radiation, Korea Research Institute of Standards and Science, Daejeon 34113, Korea
| | - Byoung-Chul Kim
- Center for Ionizing Radiation, Korea Research Institute of Standards and Science, Daejeon 34113, Korea
| | - Wook-Geun Shin
- Department of Radiation Convergence Engineering, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju, 26493, Korea
| | - Chul Hee Min
- Department of Radiation Convergence Engineering, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju, 26493, Korea
| |
Collapse
|
4
|
Vassiliev ON, Kry SF, Grosshans DR, Mohan R. Average stopping powers for electron and photon sources for radiobiological modeling and microdosimetric applications. Phys Med Biol 2018; 63:055007. [PMID: 29411712 PMCID: PMC5856245 DOI: 10.1088/1361-6560/aaad7a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study concerns calculation of the average electronic stopping power for photon and electron sources. It addresses two problems that have not yet been fully resolved. The first is defining the electron spectrum used for averaging in a way that is most suitable for radiobiological modeling. We define it as the spectrum of electrons entering the sensitive to radiation volume (SV) within the cell nucleus, at the moment they enter the SV. For this spectrum we derive a formula that combines linearly the fluence spectrum and the source spectrum. The latter is the distribution of initial energies of electrons produced by a source. Previous studies used either the fluence or source spectra, but not both, thereby neglecting a part of the complete spectrum. Our derived formula reduces to these two prior methods in the case of high and low energy sources, respectively. The second problem is extending electron spectra to low energies. Previous studies used an energy cut-off on the order of 1 keV. However, as we show, even for high energy sources, such as 60Co, electrons with energies below 1 keV contribute about 30% to the dose. In this study all the spectra were calculated with Geant4-DNA code and a cut-off energy of only 11 eV. We present formulas for calculating frequency- and dose-average stopping powers, numerical results for several important electron and photon sources, and tables with all the data needed to use our formulas for arbitrary electron and photon sources producing electrons with initial energies up to ∼1 MeV.
Collapse
Affiliation(s)
- Oleg N Vassiliev
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States of America
| | | | | | | |
Collapse
|
5
|
Zaleska K, Suchorska W, Kowalik A, Kruszyna M, Jackowiak W, Skrobala A, Skorska M, Malicki J. Low dose out-of-field radiotherapy, part 3: Qualitative and quantitative impact of scattered out-of-field radiation on MDA-MB-231 cell lines. Cancer Radiother 2017; 21:358-364. [DOI: 10.1016/j.canrad.2016.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 02/17/2016] [Accepted: 04/01/2016] [Indexed: 11/29/2022]
|
6
|
Wegener S, Sauer OA. Separation of scatter from small MV beams and its effect on detector response. Med Phys 2017; 44:1139-1148. [PMID: 28063164 DOI: 10.1002/mp.12091] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/20/2016] [Accepted: 01/01/2017] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Separating the scatter from the primary component of a MV beam to study detector response separately in each case for a better understanding of the role of different effects influencing the response in nonstandard fields. METHODS Detector response in three different experimental setups was investigated for a variety of different types (diamond, shielded and unshielded diodes, ionization chamber and film): (a). Detectors positioned in water under a thin steel pole blocking the central part of the beam, yielding only the response to the scatter part of the beam. (b). Detectors positioned in air under a PMMA cap to approximate the contribution of the primary beam without scatter. (c). Detectors positioned in water in the standard open field configuration to obtain a superposition of both. RESULTS Detector differences became more clearly observable when the primary beam was blocked and detector behavior heavily depended on the construction type. It was possible to calculate the response in the open fields from the values measured in the blocked configuration with 1% accuracy for all studied field sizes between 0.8 and 10 cm and for all detectors. CONCLUSIONS The limitations of clinically used detectors in nonstandard situations were illustrated in the extreme situation of just scattered radiation reaching the detector. By experimentally separating scatter from the primary beam, the roles of different effects on the detector response were observed.
Collapse
Affiliation(s)
- Sonja Wegener
- Department of Radiation Oncology, University of Würzburg, 97080, Würzburg, Germany
| | - Otto A Sauer
- Department of Radiation Oncology, University of Würzburg, 97080, Würzburg, Germany
| |
Collapse
|
7
|
Zahnreich S, Ebersberger A, Karle H, Kaina B, Schmidberger H. Quantification of Radiation Biomarkers in Leukocytes of Breast Cancer Patients Treated with Different Modalities of 3D-CRT or IMRT. Radiat Res 2016; 186:508-519. [DOI: 10.1667/rr14475.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | | | - Heiko Karle
- Radiation Oncology and Radiation Therapy and
| | - Bernd Kaina
- Toxicology, University Medical Center Johannes Gutenberg University Mainz, 55131 Mainz, Germany
| | | |
Collapse
|
8
|
Balderson M, Koger B, Kirkby C. The relative biological effectiveness of out-of-field dose. Phys Med Biol 2016; 61:114-30. [PMID: 26611151 DOI: 10.1088/0031-9155/61/1/114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE using simulations and models derived from existing literature, this work investigates relative biological effectiveness (RBE) for out-of-field radiation and attempts to quantify the relative magnitudes of different contributing phenomena (spectral, bystander, and low dose hypersensitivity effects). Specific attention is paid to external beam radiotherapy treatments for prostate cancer. MATERIALS AND METHODS using different biological models that account for spectral, bystander, and low dose hypersensitivity effects, the RBE was calculated for different points moving radially out from isocentre for a typical single arc VMAT prostate case. The RBE was found by taking the ratio of the equivalent dose with the physical dose. Equivalent doses were calculated by determining what physical dose would be necessary to produce the same overall biological effect as that predicted using the different biological models. RESULTS spectral effects changed the RBE out-of-field less than 2%, whereas response models incorporating low dose hypersensitivity and bystander effects resulted in a much more profound change of the RBE for out-of-field doses. The bystander effect had the largest RBE for points located just outside the edge of the primary radiation beam in the cranial caudal (z-direction) compared to low dose hypersensitivity and spectral effects. In the coplanar direction, bystander effect played the largest role in enhancing the RBE for points up to 8.75 cm from isocentre. CONCLUSIONS spectral, bystander, and low dose hypersensitivity effects can all increase the RBE for out-of-field radiation doses. In most cases, bystander effects seem to play the largest role followed by low dose hypersensitivity. Spectral effects were unlikely to be of any clinical significance. Bystander, low dose hypersensitivity, and spectral effect increased the RBE much more in the cranial caudal direction (z-direction) compared with the coplanar directions.
Collapse
Affiliation(s)
- Michael Balderson
- Department of Medical Physics, Jack Ady Cancer Center, Lethbridge, Alberta, Canada. Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | | | | |
Collapse
|
9
|
Dubois L, Biemans R, Reniers B, Bosmans G, Trani D, Podesta M, Kollaard R, Rouschop KM, Theys J, Vooijs M, Pruschy M, Verhaegen F, Lambin P. High dose rate and flattening filter free irradiation can be safely implemented in clinical practice. Int J Radiat Biol 2015; 91:778-85. [DOI: 10.3109/09553002.2015.1068457] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
10
|
Butterworth KT, McMahon SJ, McKee JC, Patel G, Ghita M, Cole AJ, McGarry CK, O'Sullivan JM, Hounsell AR, Prise KM. Time and Cell Type Dependency of Survival Responses in Co-cultured Tumor and Fibroblast Cells after Exposure to Modulated Radiation Fields. Radiat Res 2015; 183:656-64. [DOI: 10.1667/rr13992.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
11
|
Zwicker F, Swartman B, Roeder F, Sterzing F, Hauswald H, Thieke C, Weber KJ, Huber PE, Schubert K, Debus J, Herfarth K. In vivo measurement of dose distribution in patients' lymphocytes: helical tomotherapy versus step-and-shoot IMRT in prostate cancer. JOURNAL OF RADIATION RESEARCH 2015; 56:239-247. [PMID: 25361548 PMCID: PMC4380044 DOI: 10.1093/jrr/rru096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 09/07/2014] [Accepted: 09/13/2014] [Indexed: 06/04/2023]
Abstract
In radiotherapy, in vivo measurement of dose distribution within patients' lymphocytes can be performed by detecting gamma-H2AX foci in lymphocyte nuclei. This method can help in determining the whole-body dose. Options for risk estimations for toxicities in normal tissue and for the incidence of secondary malignancy are still under debate. In this investigation, helical tomotherapy (TOMO) is compared with step-and-shoot IMRT (SSIMRT) of the prostate gland by measuring the dose distribution within patients' lymphocytes. In this prospective study, blood was taken from 20 patients before and 10 min after their first irradiation fraction for each technique. The isolated leukocytes were fixed 2 h after radiation. DNA double-stranded breaks in lymphocyte nuclei were stained immunocytochemically using anti-gamma-H2AX antibodies. Gamma-H2AX foci distribution in lymphocytes was determined for each patient. Using a calibration line, dose distributions in patients' lymphocytes were determined by studying the gamma-H2AX foci distribution, and these data were used to generate a cumulative dose-lymphocyte histogram (DLH). Measured in vivo (DLH), significantly fewer lymphocytes indicated low-dose exposure (<40% of the applied dose) during TOMO compared with SSIMRT. The dose exposure range, between 45 and 100%, was equal with both radiation techniques. The mean number of gamma-H2AX foci per lymphocyte was significantly lower in the TOMO group compared with the SSIMRT group. In radiotherapy of the prostate gland, TOMO generates a smaller fraction of patients' lymphocytes with low-dose exposure relative to the whole body compared with SSIMRT. Differences in the constructional buildup of the different linear accelerator systems, e.g. the flattening filter, may be the cause thereof. The influence of these methods on the incidence of secondary malignancy should be investigated in further studies.
Collapse
Affiliation(s)
- Felix Zwicker
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Benedict Swartman
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Falk Roeder
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Florian Sterzing
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Henrik Hauswald
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Christian Thieke
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Klaus-Josef Weber
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Peter E Huber
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kai Schubert
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Klaus Herfarth
- Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| |
Collapse
|
12
|
Shields L, Vega-Carrascal I, Singleton S, Lyng FM, McClean B. Cell Survival and DNA Damage in Normal Prostate Cells Irradiated Out-of-Field. Radiat Res 2014; 182:499-506. [DOI: 10.1667/rr13777.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
13
|
Ezzati AO, Xiao Y, Sohrabpour M, Studenski MT. The effect of energy spectrum change on DNA damage in and out of field in 10-MV clinical photon beams. Med Biol Eng Comput 2014; 53:67-75. [DOI: 10.1007/s11517-014-1213-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
|
14
|
Asur R, Butterworth KT, Penagaricano JA, Prise KM, Griffin RJ. High dose bystander effects in spatially fractionated radiation therapy. Cancer Lett 2013; 356:52-7. [PMID: 24246848 DOI: 10.1016/j.canlet.2013.10.032] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 10/24/2013] [Accepted: 10/28/2013] [Indexed: 12/25/2022]
Abstract
Traditional radiotherapy of bulky tumors has certain limitations. Spatially fractionated radiation therapy (GRID) and intensity modulated radiotherapy (IMRT) are examples of advanced modulated beam therapies that help in significant reductions in normal tissue damage. GRID refers to the delivery of a single high dose of radiation to a large treatment area that is divided into several smaller fields, while IMRT allows improved dose conformity to the tumor target compared to conventional three-dimensional conformal radiotherapy. In this review, we consider spatially fractionated radiotherapy approaches focusing on GRID and IMRT, and present complementary evidence from different studies which support the role of radiation induced signaling effects in the overall radiobiological rationale for these treatments.
Collapse
Affiliation(s)
- Rajalakshmi Asur
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Karl T Butterworth
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Jose A Penagaricano
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Kevin M Prise
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Robert J Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States.
| |
Collapse
|
15
|
Choi VWY, Yu KN. Embryos of the zebrafish Danio rerio in studies of non-targeted effects of ionizing radiation. Cancer Lett 2013; 356:91-104. [PMID: 24176822 DOI: 10.1016/j.canlet.2013.10.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 10/16/2013] [Accepted: 10/22/2013] [Indexed: 01/17/2023]
Abstract
The use of embryos of the zebrafish Danio rerio as an in vivo tumor model for studying non-targeted effects of ionizing radiation was reviewed. The zebrafish embryo is an animal model, which enables convenient studies on non-targeted effects of both high-linear-energy-transfer (LET) and low-LET radiation by making use of both broad-beam and microbeam radiation. Zebrafish is also a convenient embryo model for studying radiobiological effects of ionizing radiation on tumors. The embryonic origin of tumors has been gaining ground in the past decades, and efforts to fight cancer from the perspective of developmental biology are underway. Evidence for the involvement of radiation-induced genomic instability (RIGI) and the radiation-induced bystander effect (RIBE) in zebrafish embryos were subsequently given. The results of RIGI were obtained for the irradiation of all two-cell stage cells, as well as 1.5 hpf zebrafish embryos by microbeam protons and broad-beam alpha particles, respectively. In contrast, the RIBE was observed through the radioadaptive response (RAR), which was developed against a subsequent challenging dose that was applied at 10 hpf when <0.2% and <0.3% of the cells of 5 hpf zebrafish embryos were exposed to a priming dose, which was provided by microbeam protons and broad-beam alpha particles, respectively. Finally, a perspective on the field, the need for future studies and the significance of such studies were discussed.
Collapse
Affiliation(s)
- V W Y Choi
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong
| | - K N Yu
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong; State Key Laboratory in Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong.
| |
Collapse
|
16
|
Byrne HL, McNamara AL, Domanova W, Guatelli S, Kuncic Z. Radiation damage on sub-cellular scales: beyond DNA. Phys Med Biol 2013; 58:1251-67. [DOI: 10.1088/0031-9155/58/5/1251] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
17
|
McGarry CK, Butterworth KT, Trainor C, McMahon SJ, O'Sullivan JM, Prise KM, Hounsell AR. In-vitro investigation of out-of-field cell survival following the delivery of conformal, intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans. Phys Med Biol 2012; 57:6635-45. [PMID: 23022685 DOI: 10.1088/0031-9155/57/20/6635] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this work is to determine the out-of-field survival of cells irradiated with either the primary field or scattered radiation in the presence and absence of intercellular communication following delivery of conformal, IMRT and VMAT treatment plans. Single beam, conformal, IMRT and VMAT plans were created to deliver 3 Gy to half the area of a T80 flask containing either DU-145 or AGO-1522 cells allowing intercellular communication between the in- and out-of-field cell populations. The same plans were delivered to a similar custom made phantom used to hold two T25 culture flasks, one flask in-field and one out-of-field to allow comparison of cell survival responses when intercellular communication is physically inhibited. Plans were created for the delivery of 8 Gy to the more radio-resistant DU-145 cells only in the presence and absence of intercellular communication. Cell survival was determined by clonogenic assay. In both cell lines, the out-of-field survival was not statistically different between delivery techniques for either cell line or dose. There was however, a statistically significant difference between survival out-of-field when intercellular communication was intact (single T80 culture flask) or inhibited (multiple T25 culture flasks) to in-field for all plans. No statistically significant difference was observed in-field with or without cellular communication to out-of-field for all plans. These data demonstrate out-of-field effects as important determinants of cell survival following exposure to modulated irradiation fields when cellular communication between differentially irradiated cell populations is present. This data is further evidence that refinement of existing radiobiological models to include indirect cell killing effects is required.
Collapse
Affiliation(s)
- Conor K McGarry
- Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, UK.
| | | | | | | | | | | | | |
Collapse
|
18
|
DNA damage responses following exposure to modulated radiation fields. PLoS One 2012; 7:e43326. [PMID: 22912853 PMCID: PMC3422245 DOI: 10.1371/journal.pone.0043326] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 07/19/2012] [Indexed: 11/19/2022] Open
Abstract
During the delivery of advanced radiotherapy treatment techniques modulated beams are utilised to increase dose conformity across the target volume. Recent investigations have highlighted differential cellular responses to modulated radiation fields particularly in areas outside the primary treatment field that cannot be accounted for by scattered dose alone. In the present study, we determined the DNA damage response within the normal human fibroblast AG0-1522B and the prostate cancer cell line DU-145 utilising the DNA damage assay. Cells plated in slide flasks were exposed to 1 Gy uniform or modulated radiation fields. Modulated fields were delivered by shielding 25%, 50% or 75% of the flask during irradiation. The average number of 53BP1 or γH2AX foci was measured in 2 mm intervals across the slide area. Following 30 minutes after modulated radiation field exposure an increase in the average number of foci out-of-field was observed when compared to non-irradiated controls. In-field, a non-uniform response was observed with a significant decrease in the average number of foci compared to uniformly irradiated cells. Following 24 hrs after exposure there is evidence for two populations of responding cells to bystander signals in-and out-of-field. There was no significant difference in DNA damage response between 25%, 50% or 75% modulated fields. The response was dependent on cellular secreted intercellular signalling as physical inhibition of intercellular communication abrogated the observed response. Elevated residual DNA damage observed within out-of-field regions decreased following addition of an inducible nitric oxide synthase inhibitor (Aminoguanidine). These data show, for the first time, differential DNA damage responses in-and out-of-field following modulated radiation field delivery. This study provides further evidence for a role of intercellular communication in mediating cellular radiobiological response to modulated radiation fields and may inform the refinement of existing radiobiological models for the optimization of advanced radiotherapy treatment plans.
Collapse
|
19
|
Chofor N, Harder D, Willborn KC, Poppe B. Internal scatter, the unavoidable major component of the peripheral dose in photon-beam radiotherapy. Phys Med Biol 2012; 57:1733-43. [PMID: 22398213 DOI: 10.1088/0031-9155/57/6/1733] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In clinical photon beams, the dose outside the geometrical field limits is produced by photons originating from (i) head leakage, (ii) scattering at the beam collimators and the flattening filter (head scatter) and (iii) scattering from the directly irradiated region of the patient or phantom (internal scatter). While the first two components can be modified, e.g. by reinforcement of shielding components or by re-modeling the filter system, internal scatter remains an unavoidable contributor to the peripheral dose. Its relative magnitude compared to the other components, its numerical variation with beam energy, field size and off-axis distance as well as its spectral distribution are evaluated in this study. We applied a detailed Monte Carlo (MC) model of our 6/15 MV Siemens Primus linear accelerator beam head, provided with ideal head leakage shielding conditions (multi-leaf collimator without gaps) to assess the head scatter contribution. Experimental values obtained under real shielding conditions were used to evaluate the head leakage contribution. It was found that the MC-computed internal scatter doses agree with the results of our previous measurements, that internal scatter is the major contributor to the peripheral dose in the near periphery while head leakage prevails in the far periphery, and that the lateral decline of the internal scatter dose can be represented by the sum of two exponentials, with an asymptotic tenth value of 18 to 19 cm. Internal scatter peripheral doses from various elementary beams are additive, so that their sum increases approximately in proportion with field size. The ratio between normalized internal scatter doses at 6 and 15 MV is approximately 2:1. The energy fluence spectra of the internal scatter component at all points of interest outside the field have peaks near 500 keV. The fact that the energy-shifted internal scatter constitutes the major contributor to the dose in the near periphery has a general bearing for dosimetry, i.e. for energy-dependent detector responses and dose conversion factors, for the relative biological effectiveness and for second primary malignancy risk estimates in the peripheral region.
Collapse
Affiliation(s)
- Ndimofor Chofor
- Clinic for Radiation Therapy, Pius-Hospital, and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg, Germany.
| | | | | | | |
Collapse
|
20
|
Trainor C, Butterworth KT, McGarry CK, Liberante F, O'Sullivan JM, Hounsell AR, Prise KM. Cell survival responses after exposure to modulated radiation fields. Radiat Res 2011; 177:44-51. [PMID: 22029841 DOI: 10.1667/rr2656.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In the present study survival responses were determined in cells with differing radiosensitivity, specifically primary fibroblast (AG0-1522B), human breast cancer (MDA-MB-231), human prostate cancer (DU-145) and human glioma (T98G) cells, after exposure to modulated radiation fields delivered by shielding 50% of the tissue culture flask. A significant decrease (P < 0.05) in cell survival was observed in the shielded area, outside the primary treatment field (out-of-field), that was lower than predicted when compared to uniform exposures fitted to the linear-quadratic model. Cellular radiosensitivity was demonstrated to be an important factor in the level of response for both the in- and out-of-field regions. These responses were shown to be dependent on secretion-mediated intercellular communication, because inhibition of cellular secreted factors between the in- and out-of-field regions abrogated the response. Out-of-field cell survival was shown to increase after pretreatment of cells with agents known to inhibit factors involved in mediating radiation-induced bystander signaling (aminoguanidine, DMSO or cPTIO). These data illustrate a significant decrease in survival out-of-field, dependent upon intercellular communication, in several cell lines with varying radiosensitivity after exposure to a modulated radiation field. This study provides further evidence for the importance of intercellular signaling in modulated exposures, where dose gradients are present, and may inform the refinement of established radiobiological models to facilitate the optimization of advanced radiotherapy treatment plans.
Collapse
Affiliation(s)
- C Trainor
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom.
| | | | | | | | | | | | | |
Collapse
|
21
|
Low-energy photons in high-energy photon fields – Monte Carlo generated spectra and a new descriptive parameter. Z Med Phys 2011; 21:183-97. [DOI: 10.1016/j.zemedi.2011.02.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 02/17/2011] [Accepted: 02/19/2011] [Indexed: 12/22/2022]
|
22
|
Okamoto H, Kohno T, Kanai T, Kase Y, Matsumoto Y, Furusawa Y, Fujita Y, Saitoh H, Itami J. Microdosimetric study on influence of low energy photons on relative biological effectiveness under therapeutic conditions using 6 MV linac. Med Phys 2011; 38:4714-22. [DOI: 10.1118/1.3613152] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
23
|
Chofor N, Harder D, Willborn K, Rühmann A, Poppe B. A direction-selective flattening filter for clinical photon beams. Monte Carlo evaluation of a new concept. Phys Med Biol 2011; 56:4355-76. [DOI: 10.1088/0031-9155/56/14/009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
24
|
Butterworth KT, McGarry CK, Trainor C, O'Sullivan JM, Hounsell AR, Prise KM. Out-of-field cell survival following exposure to intensity-modulated radiation fields. Int J Radiat Oncol Biol Phys 2011; 79:1516-22. [PMID: 21277116 DOI: 10.1016/j.ijrobp.2010.11.034] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 11/02/2010] [Accepted: 11/04/2010] [Indexed: 10/18/2022]
Abstract
PURPOSE To determine the in-field and out-of-field cell survival of cells irradiated with either primary field or scattered radiation in the presence and absence of intercellular communication. METHODS AND MATERIALS Cell survival was determined by clonogenic assay in human prostate cancer (DU145) and primary fibroblast (AGO1552) cells following exposure to different field configurations delivered using a 6-MV photon beam produced with a Varian linear accelerator. RESULTS Nonuniform dose distributions were delivered using a multileaf collimator (MLC) in which half of the cell population was shielded. Clonogenic survival in the shielded region was significantly lower than that predicted from the linear quadratic model. In both cell lines, the out-of-field responses appeared to saturate at 40%-50% survival at a scattered dose of 0.70 Gy in DU-145 cells and 0.24 Gy in AGO1522 cells. There was an approximately eightfold difference in the initial slopes of the out-of-field response compared with the α-component of the uniform field response. In contrast, cells in the exposed part of the field showed increased survival. These observations were abrogated by direct physical inhibition of cellular communication and by the addition of the inducible nitric oxide synthase inhibitor aminoguanidine known to inhibit intercellular bystander effects. Additional studies showed the proportion of cells irradiated and dose delivered to the shielded and exposed regions of the field to impact on response. CONCLUSIONS These data demonstrate out-of-field effects as important determinants of cell survival following exposure to modulated irradiation fields with cellular communication between differentially irradiated cell populations playing an important role. Validation of these observations in additional cell models may facilitate the refinement of existing radiobiological models and the observations considered important determinants of cell survival.
Collapse
Affiliation(s)
- Karl T Butterworth
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom.
| | | | | | | | | | | |
Collapse
|
25
|
Okamoto H, Kanai T, Kase Y, Matsumoto Y, Furusawa Y, Fujita Y, Saitoh H, Itami J, Kohno T. Relation between lineal energy distribution and relative biological effectiveness for photon beams according to the microdosimetric kinetic model. JOURNAL OF RADIATION RESEARCH 2011; 52:75-81. [PMID: 21160135 DOI: 10.1269/jrr.10073] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Our cell survival data showed the obvious dependence of RBE on photon energy: The RBE value for 200 kV X-rays was approximately 10% greater than those for mega-voltage photon beams. In radiation therapy using mega-voltage photon beams, the photon energy distribution outside the field is different with that in the radiation field because of a large number of low energy scattering photons. Hence, the RBE values outside the field become greater. To evaluate the increase in RBE, the method of deriving the RBE using the Microdosimetric Kinetic model (MK model) was proposed in this study. The MK model has two kinds of the parameters, tissue-specific parameters and the dose-mean lineal energy derived from the lineal energy distributions measured with a Tissue-Equivalent Proportional Counter (TEPC). The lineal energy distributions with the same geometries of the cell irradiations for 200 kV X-rays, (60)Co γ-rays, and 6 MV X-rays were obtained with the TEPC and Monte Carlo code GEANT4. The measured lineal energy distribution for 200 kV X-rays was quite different from those for mega-voltage photon beams. The dose-mean lineal energy of 200 kV X-rays showed the greatest value, 4.51 keV/µm, comparing with 2.34 and 2.36 keV/µm for (60)Co γ-rays and 6 MV X-rays, respectively. By using the results of the TEPC and cell irradiations, the tissue-specific parameters in the MK model were determined. As a result, the RBE of the photon beams (y(D): 2~5 keV/µm) in arbitrary conditions can be derived by the measurements only or the calculations only of the dose-mean lineal energy.
Collapse
Affiliation(s)
- Hiroyuki Okamoto
- Department of Energy Sciences, Tokyo Institute of Technology, Kanagawa, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Chofor N, Harder D, Rühmann A, Willborn KC, Wiezorek T, Poppe B. Experimental study on photon-beam peripheral doses, their components and some possibilities for their reduction. Phys Med Biol 2010; 55:4011-27. [DOI: 10.1088/0031-9155/55/14/005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|