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D P, D K, P M, Bhalla NK, R P, M C, Puri A. A Study to Analyze Impact of Treatment Couch and Immobilization Devices on Surface Dose for Megavoltage Photon Beams. Asian Pac J Cancer Prev 2023; 24:4133-4138. [PMID: 38156848 PMCID: PMC10909093 DOI: 10.31557/apjcp.2023.24.12.4133] [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] [Received: 06/23/2023] [Accepted: 12/17/2023] [Indexed: 01/03/2024] Open
Abstract
PURPOSE/OBJECTIVE The purpose of this study is to investigate the effect of treatment couch and immobilization devices on surface dose for megavoltage photon beams. MATERIAL/METHODS Percentage surface dose (PSD) measurement was carried out in Elekta Synergy™ Linear accelerator using PTW Markus® Parallel plate ionization chamber of volume 0.05cm3 with water equivalent RW3 Slab phantom (PTW, Germany). The measurement depth was considered at 0.07mm. The reference PSD was measured at 0° gantry angle with 10×10cm2, 20×20cm2 and 30×30cm2 field sizes and 100cm SSD for 4MV, 6MV and 15MV photon beams. For comparison, PSD measurement was carried out at 180° gantry angle inclusion of treatment couch (TC), All in One positioning system (AIO - PS) and Vac lok Cushions (VLC). RESULTS Beam angle at 0°, for field sizes 10×10cm2, 20×20cm2 and 30×30cm2, the PSD was observed as 30.9%, 40.5%, 48.7% for 4MV; 23.7%, 33.8%, 42.2% for 6MV; and 17.0%, 29.6%, 38.6% for 15MV respectively. Beam angle at 180° with TC, an increase in PSD by maximum of 65.0% for 4MV, 64.9% for 6MV and 55.9% for 15MV as compared to 0° angle. The PSD increased when beam angle was 180° with TC and AIO - PS were 65.0% for 4MV, 67.4% for 6MV, and 60.9% for 15MV than 0° angle. Similarly, increased PSD for beam angle at 180° with TC and VLC were 66.8% for 4MV, 66.8% for 6MV and 61.3% for 15MV as compared to 0° angle. CONCLUSION For all three-photon energies, at 180° gantry angle, the PSD increased significantly in case of TC, VLC, and AIO - PS for all the field sizes as compared to gantry angle at 0°. It is necessary to consider TC, AIO - PS and VLC during dose calculation to ensure accuracy of patient treatment delivery.
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Affiliation(s)
- Palanivelu D
- Department of Physical Sciences, School of Sciences, Arts and Media, Karunya Institute of Technology and Sciences, Coimbatore, Tamilnadu, India
- Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India
| | - Khanna D
- Department of Physical Sciences, School of Sciences, Arts and Media, Karunya Institute of Technology and Sciences, Coimbatore, Tamilnadu, India
| | - Mohandass P
- Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India
| | - Narandra Kumar Bhalla
- Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India
| | - Prabhu R
- Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India
| | - Chandru M
- Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India
| | - Abhishek Puri
- Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India
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Niroomand‐Rad A, Chiu‐Tsao S, Grams MP, Lewis DF, Soares CG, Van Battum LJ, Das IJ, Trichter S, Kissick MW, Massillon‐JL G, Alvarez PE, Chan MF. Report of AAPM Task Group 235 Radiochromic Film Dosimetry: An Update to TG‐55. Med Phys 2020; 47:5986-6025. [DOI: 10.1002/mp.14497] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Affiliation(s)
| | | | | | | | | | | | - Indra J. Das
- Radiation Oncology Northwestern University Memorial Hospital Chicago IL USA
| | - Samuel Trichter
- New York‐Presbyterian HospitalWeill Cornell Medical Center New York NY USA
| | | | - Guerda Massillon‐JL
- Instituto de Fisica Universidad Nacional Autonoma de Mexico Mexico City Mexico
| | - Paola E. Alvarez
- Imaging and Radiation Oncology Core MD Anderson Cancer Center Houston TX USA
| | - Maria F. Chan
- Memorial Sloan Kettering Cancer Center Basking Ridge NJ USA
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Verde Nolasco A, de Faria LO. Head and Neck Immobilization Masks: Increase in Dose Surface Evaluated by EBT3, TLD‐100 and PBC Method. PRECISION RADIATION ONCOLOGY 2020. [DOI: 10.1002/pro6.1097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Arnie Verde Nolasco
- Department of Medical Physics São Francisco Radiotherapy Institute Itapagipe 762 Belo Horizonte Minas Gerais Brasil
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Cho JD, Son J, Sung J, Choi CH, Kim JS, Wu HG, Park JM, Kim JI. Flexible film dosimeter for in vivo dosimetry. Med Phys 2020; 47:3204-3213. [PMID: 32248523 DOI: 10.1002/mp.14162] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 02/03/2023] Open
Abstract
PURPOSE The aims of this study were to develop a flexible film dosimeter applicable to the irregular surface of a patient for in vivo dosimetry and to evaluate the device's dosimetric characteristics. METHODS A flexible film dosimeter with active layers consisting of radiochromic-sensitive films and flexible silicone materials was constructed. The dose-response, sensitivity, scanning orientation dependence, energy dependence, and dose rate dependence of the flexible film dosimeter were tested. Irradiated dosimeters were scanned 24 h post-irradiation, and the region of interest was 5 mm × 5 mm. Biological stability tests ensured the safety of application of the flexible film dosimeter for patients. A preliminary clinical study with the flexible film dosimeter was implemented on four patients. RESULTS The red channel demonstrated the highest sensitivity among all channels, and the response sensitivity of the dosimeter decreased with the applied dose, which were the same as the characteristics of GAFCHROMIC EBT3 radiochromic films. The flexible film dosimeter showed no significant energy dependence for photon beams of 6 MV, 6 MV flattening filter-free (FFF), 10 MV, and 15 MV. The flexible film dosimeter showed no substantial dose rate dependence with 6 or 6 MV FFF. In terms of biological stability, the flexible film dosimeter demonstrated no cytotoxicity, no irritation, and no skin sensitization. In the preliminary clinical study, the dose differences between the measurements with the flexible film dosimeter and calculations with the treatment planning system ranged from -0.1% to 1.2% for all patients. CONCLUSIONS The dosimeter developed in this study is a flexible film capable of attachment to a curved skin surface. The biological test results indicate the stability of the flexible film dosimeter. The preliminary clinical study showed that the flexible film dosimeter can be successfully applied as an in vivo dosimeter.
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Affiliation(s)
- Jin Dong Cho
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, 03080, Republic of Korea.,Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
| | - Jaeman Son
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Jiwon Sung
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Chang Heon Choi
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Jin Sung Kim
- Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
| | - Hong-Gyun Wu
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.,Cancer Research Institute, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Jong Min Park
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Robotics Research Laboratory for Extreme Environments, Advanced Institute of Convergence Technology, Suwon, 16229, Republic of Korea
| | - Jung-In Kim
- Department of Radiation Oncology, Seoul National University Hospital, Seoul, 03080, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, 03080, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, 03080, Republic of Korea
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5
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Arab-Bafrani Z, Mahani L, Khoshbin-Khoshnazar A, Kermani MZ. Three dimensional film dosimetry of photon beam in small field sizes and beyond the heterogeneous regions using a GAFchromic films array. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2019.108467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Rijken J, Kairn T, Crowe S, Muñoz L, Trapp J. A simple method to account for skin dose enhancement during treatment planning of VMAT treatments of patients in contact with immobilization equipment. J Appl Clin Med Phys 2018; 19:239-245. [PMID: 29934993 PMCID: PMC6036355 DOI: 10.1002/acm2.12394] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/29/2018] [Accepted: 06/01/2018] [Indexed: 12/31/2022] Open
Abstract
Purpose The ability to accurately predict skin doses and thereby design radiotherapy treatments that balance the likelihood of skin reactions against other treatment objectives is especially important when hypofractionated prescription regimes are used. However, calculations of skin dose provided by many commercial radiotherapy treatment planning systems are known to be inaccurate, especially if the presence of immobilization equipment is not accurately taken into account. This study proposes a simple method by which the accuracy of skin dose calculations can be substantially improved, to allow informed evaluation of volumetric modulated arc therapy (VMAT) treatment plans. Method A simple method was developed whereby dose calculation is split into grid regions, each with a correction factor which determines MU scaling for skin dose calculation. Correction factors were derived from film measurements made using a geometrically simple phantom in partial contact with a vacuum immobilization device. This method was applied to two different test treatments, planned for delivery to a humanoid phantom with a hypofractionated stereotactic body radiotherapy technique, and results were verified using film measurements of surface dose. Results Compared to the measured values, calculations of skin dose volumes corresponding to different grade tissue reactions were greatly improved through use of the method employed in this study. In some cases, the accuracy of skin dose evaluation improved by 76% and brought values to within 3% of those measured. Conclusion The method of skin dose calculation in this study is simple, can be made as accurate as the user requires and is applicable for various immobilization systems. This concept has been verified through use on SBRT lung treatment plans and will aid clinicians in predicting skin response in patients.
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Affiliation(s)
- James Rijken
- Genesis Care, Flinders Private Hospital, Bedford Park, SA, Australia.,Queensland University of Technology, Brisbane, QLD, Australia
| | - Tanya Kairn
- Queensland University of Technology, Brisbane, QLD, Australia.,Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Scott Crowe
- Queensland University of Technology, Brisbane, QLD, Australia.,Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Luis Muñoz
- Genesis Care, Flinders Private Hospital, Bedford Park, SA, Australia
| | - Jamie Trapp
- Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
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Eyadeh MM, Wierzbicki M, Diamond KR. Measurement of skin surface dose distributions in radiation therapy using poly(vinyl alcohol) cryogel dosimeters. J Appl Clin Med Phys 2017; 18:153-162. [PMID: 28436134 PMCID: PMC5689842 DOI: 10.1002/acm2.12087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 02/19/2017] [Accepted: 03/13/2017] [Indexed: 11/10/2022] Open
Abstract
In external beam radiation therapy (EBRT), skin dose measurement is important to evaluate dose coverage of superficial target volumes. Treatment planning systems (TPSs) are often inaccurate in this region of the patient, so in vivo measurements are necessary for skin surface dose estimation. In this work, superficial dose distributions were measured using radiochromic translucent poly(vinyl alcohol) cryogels. The cryogels simultaneously served as bolus material, providing the necessary buildup to achieve the desired superficial dose. The relationship between dose to the skin surface and dose measured with the bolus was established using a series of oblique irradiations with gantry angles ranging from 0° to 90°. EBT-2 Gafchromic film was placed under the bolus, and the ratio of bolus-film dose was determined ranging from 0.749 ± 0.005 to 0.930 ± 0.002 for 0° and 90° gantry angles, respectively. The average ratio over 0-67.5° (0.800 ± 0.064) was used as the single correction factor to convert dose in bolus to dose to the skin surface. The correction factor was applied to bolus measurements of skin dose from head and neck intensity-modulated radiation therapy (IMRT) treatments delivered to a RANDO phantom. The resulting dose distributions were compared to film measurements using gamma analysis with a 3%/3 mm tolerance and a 10% threshold. The minimum gamma pass rate was 95.2% suggesting that the radiochromic bolus may provide an accurate estimation of skin surface dose using a simple correction factor. This study demonstrates the suitability of radiochromic cryogels for superficial dose measurements in megavoltage photon beams.
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Affiliation(s)
- Molham M Eyadeh
- Physics Department, Faculty of Science, Yarmouk University, Irbid, Jordan
| | - Marcin Wierzbicki
- Department of Medical Physics and Applied Radiation Sciences, Juravinski Cancer Centre, McMaster University, Hamilton, ON, Canada
| | - Kevin R Diamond
- Department of Medical Physics and Applied Radiation Sciences, Juravinski Cancer Centre, McMaster University, Hamilton, ON, Canada
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In vivo skin dose measurement using MOSkin detectors in tangential breast radiotherapy. Phys Med 2016; 32:1466-1474. [PMID: 27842982 DOI: 10.1016/j.ejmp.2016.10.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 10/04/2016] [Accepted: 10/24/2016] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study is to measure patient skin dose in tangential breast radiotherapy. Treatment planning dose calculation algorithm such as Pencil Beam Convolution (PBC) and in vivo dosimetry techniques such as radiochromic film can be used to accurately monitor radiation doses at tissue depths, but they are inaccurate for skin dose measurement. A MOSFET-based (MOSkin) detector was used to measure skin dose in this study. Tangential breast radiotherapies ("bolus" and "no bolus") were simulated on an anthropomorphic phantom and the skin doses were measured. Skin doses were also measured in 13 patients undergoing each of the techniques. In the patient study, the EBT2 measurements and PBC calculation tended to over-estimate the skin dose compared with the MOSkin detector (p<0.05) in the "no bolus radiotherapy". No significant differences were observed in the "bolus radiotherapy" (p>0.05). The results from patients were similar to that of the phantom study. This shows that the EBT2 measurement and PBC calculation, while able to predict accurate doses at tissue depths, are inaccurate in predicting doses at build-up regions. The clinical application of the MOSkin detectors showed that the average total skin doses received by patients were 1662±129cGy (medial) and 1893±199cGy (lateral) during "no bolus radiotherapy". The average total skin doses were 4030±72cGy (medial) and 4004±91cGy (lateral) for "bolus radiotherapy". In some cases, patient skin doses were shown to exceed the dose toxicity level for skin erythema. Hence, a suitable device for in vivo dosimetry is necessary to accurately determine skin dose.
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Tamponi M, Bona R, Poggiu A, Marini P. A new form of the calibration curve in radiochromic dosimetry. Properties and results. Med Phys 2016; 43:4435. [DOI: 10.1118/1.4954208] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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10
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Dufreneix S, Ostrowsky A, Rapp B, Daures J, Bordy JM. Accuracy of a dose-area product compared to an absorbed dose to water at a point in a 2 cm diameter field. Med Phys 2016; 43:4085. [DOI: 10.1118/1.4953207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Connor M, Wei RL, Yu S, Sehgal V, Klempner SJ, Daroui P. Radiation dermatitis caused by a bolus effect from an abdominal compression device. Med Dosim 2016; 41:221-4. [PMID: 27264694 DOI: 10.1016/j.meddos.2016.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 01/18/2016] [Accepted: 02/29/2016] [Indexed: 12/25/2022]
Abstract
American Association of Physicists in Medicine (AAPM) Task Group 176 evaluated the dosimetric effects caused by couch tops and immobilization devices. The report analyzed the extensive physics-based literature on couch tops, stereotactic body radiation therapy (SBRT) frames, and body immobilization bags, while noting the scarcity of clinical reports of skin toxicity because of external devices. Here, we present a clinical case report of grade 1 abdominal skin toxicity owing to an abdominal compression device. We discuss the dosimetric implications of the utilized treatment plan as well as post hoc alternative plans and quantify differences in attenuation and skin dose/build-up between the device, a lower-density alternative device, and an open field. The description of the case includes a 66-year-old male with HER2 amplified poorly differentiated distal esophageal adenocarcinoma treated with neoadjuvant chemo-radiation and the use of an abdominal compression device. Radiation was delivered using volumetric modulated arc therapy (VMAT) with 2 arcs using abdominal compression and image guidance. The total dose was 50.4Gy delivered over 40 elapsed days. With 2 fractions remaining, the patient developed dermatitis in the area of the compression device. The original treatment plan did not include a contour of the device. Alternative post hoc treatment plans were generated, one to contour the device and a second with anterior avoidance. In conclusion, replanning with the device contoured revealed the bolus effect. The skin dose increased from 27 to 36Gy. planned target volume (PTV) coverage at 45Gy was reduced to 76.5% from 95.8%. The second VMAT treatment plan with an anterior avoidance sector and more oblique beam angles maintained PTV coverage and spared the anterior wall, however at the expense of substantially increased dose to lung. This case report provides an important reminder of the bolus effect from external devices such as abdominal compression. Special consideration must be given to contour and/or avoiding beam entrance to the device, and to the use of such devices in patients who may have heightened radiosensitivity, such as those who are human immunodeficiency virus (HIV)-positive.
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Affiliation(s)
- Michael Connor
- Department of Radiation Oncology, University of California, Irvine Medical Center, Orange, CA
| | - Randy L Wei
- Department of Radiation Oncology, University of California, Irvine Medical Center, Orange, CA
| | - Suhong Yu
- Department of Radiation Oncology, University of California, Irvine Medical Center, Orange, CA
| | - Varun Sehgal
- Department of Radiation Oncology, University of California, Irvine Medical Center, Orange, CA
| | - Samuel J Klempner
- Department of Medicine, Division of Hematology/Oncology, University of California, Orange, CA
| | - Parima Daroui
- Department of Radiation Oncology, University of California, Irvine Medical Center, Orange, CA.
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Sharma S, Chaudhari P, Biswas A, Manigandan D. Impact of head immobilization position on dose distribution in patients of brainstem glioma. INTERNATIONAL JOURNAL OF CANCER THERAPY AND ONCOLOGY 2015. [DOI: 10.14319/ijcto.0301.16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Assessment of skin dose modification caused by application of immobilizing cast in head and neck radiotherapy. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2014; 37:535-40. [DOI: 10.1007/s13246-014-0283-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022]
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Olch AJ, Gerig L, Li H, Mihaylov I, Morgan A. Dosimetric effects caused by couch tops and immobilization devices: Report of AAPM Task Group 176. Med Phys 2014; 41:061501. [DOI: 10.1118/1.4876299] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Cho GA, Ralston A, Tin MM, Martin D, Pickard S, Kim JH, Tse R. In vivoand phantom measurements versus Eclipse TPS prediction of near surface dose for SBRT treatments. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/489/1/012008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Chan MF, Lewis D, Yu X. Is It Possible to Publish a Calibration Function for Radiochromic Film? INTERNATIONAL JOURNAL OF MEDICAL PHYSICS, CLINICAL ENGINEERING AND RADIATION ONCOLOGY 2014; 3:25-30. [PMID: 27642545 PMCID: PMC5023153 DOI: 10.4236/ijmpcero.2014.31005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To assess the possibility of using a public calibration function for radiochromic film dosimetry in dose QA of highly conformal treatment plans. METHODS EBT3 film calibration strips (3.5 × 20 cm2 from lots A101212 and A011713) were exposed on a Varian Trilogy at a facility to a 10 × 10 cm2 open field at doses of 80, 160, 320 cGy using 6MV photons. Together with a strip of unexposed film from the same lot the exposed films were digitized in a single scan using different Epson 10,000 XL scanners at two different facilities. The dose-response data for each color-channel from each facility were generated using the same calibration function X(D) = a + b/(D - c), where X(D) is the response at dose D and a, b and c are the coefficients. Different batches of EBT3 film were exposed to a VMAT beam. These films, plus two reference strips exposed to doses of zero and 160 cGy, were digitized on the scanners at the two facilities. Using the multi-channel dosimetry method and One-scan protocol (Med Phys, 39:6339-49, 2012) the recorded doses on the VMAT films were calculated and the results were compared with the VMAT plan using a Gamma index of 3%/3 mm. RESULTS The passing rates obtained for dose maps calculated for all combinations of VMAT images and calibration functions were nearly unchanged, using the One-scan protocol. Also, in all cases a passing rate of >99% was obtained for Gamma index of 3%/3 mm. On the other hand, if the One-scan protocol was not employed, the dose maps for VMAT images and calibration functions from different scanners showed poor correlation with the treatment plan. This is probably due to the scan-to-scan variability. CONCLUSIONS The authors have found that it is feasible to use a public calibration function for a given radiochromic film lot using the same methodology, One-scan protocol, for patient-specific QA.
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Affiliation(s)
- Maria F. Chan
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, Basking Ridge, USA
| | - David Lewis
- Advanced Materials Group, Ashland, Inc., Bridgewater, USA
| | - Xiang Yu
- Advanced Materials Group, Ashland, Inc., Bridgewater, USA
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Vyas V, Palmer L, Mudge R, Jiang R, Fleck A, Schaly B, Osei E, Charland P. On bolus for megavoltage photon and electron radiation therapy. Med Dosim 2013; 38:268-73. [PMID: 23582702 DOI: 10.1016/j.meddos.2013.02.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 02/06/2013] [Accepted: 02/19/2013] [Indexed: 11/19/2022]
Abstract
Frequently, in radiation therapy one must treat superficial lesions on cancer patients; these are at or adjacent to the skin. Megavoltage photon radiotherapy penetrates through the skin to irradiate deep-seated tumors, with skin-sparing property. Hence, to treat superficial lesions, one must use a layer of scattering material to feign as the skin surface. Although megavoltage electron beams are used for superficial treatments, one occasionally needs to enhance the dose near the surface. Such is the function of a "bolus," a natural or synthetically developed material that acts as a layer of tissue to provide a more effective treatment to the superficial lesions. Other uses of boluses are to correct for varying surface contours and to add scattering material around the patient's surface. Materials used as bolus vary from simple water to metal and include various mixtures and compounds. Even with the modernization of the technology for external-beam therapy and the emergence of various commercial boluses, the preparation and utilization of a bolus in clinical radiotherapy remains an art. Considering the varying experiences and practices, this paper briefly summarizes available boluses that have been proposed and are employed in clinical radiotherapy. Although this review is not exhaustive, it provides some initial guidance and answers questions that may arise in clinical practice.
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Affiliation(s)
- Vedang Vyas
- University of Waterloo, Waterloo, Ontario, Canada; Grand River Regional Cancer Centre, Kitchener, Ontario, Canada
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Lewis D, Micke A, Yu X, Chan MF. An efficient protocol for radiochromic film dosimetry combining calibration and measurement in a single scan. Med Phys 2012; 39:6339-50. [PMID: 23039670 DOI: 10.1118/1.4754797] [Citation(s) in RCA: 266] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Radiochromic film provides dose measurement at high spatial resolution, but often is not preferred for routine evaluation of patient-specific intensity modulated radiation therapy (IMRT) plans owing to ease-of-use factors. The authors have established an efficient protocol that combines calibration and measurement in a single scan and enables measurement results to be obtained in less than 30 min. This avoids complications due to postexposure changes in radiochromic film that delay the completion of a measurement, often for up to 24 h, in commonly used methods. In addition, the protocol addresses the accuracy and integrity of the measurement by eliminating environmental and interscan variability issues. METHODS The authors collected dose-response data from six production lots of Gafchromic EBT3 film and three production lots of EBT2 film at doses up to 480 cGy. In this work, the authors used seven different scanners of two different models-Epson 10000XL and V700; postexposure times before scanning from 30 min to 9 days; ambient temperatures for scanning spanning 11 °C; and two film orientations. Scanning was in 48-bit RGB format at 72 dpi resolution. Dose evaluation was conducted using a triple-channel dosimetry method. To evaluate the measurement protocol, patient specific IMRT and volumetric modulated arc therapy (VMAT) plans were exposed onto EBT3 films on a Varian Trilogy Linac. Film scanning was done following the protocol under a number of different conditions and the dose maps were analyzed to demonstrate the equivalence of results. RESULTS The results indicated that the dose-response data could be fit by a set of related rational functions leading to the description of a generic calibration curve. A simplified dosimetry protocol was established where dose-response data for a specific film lot, scanner, and scanning conditions could be derived from two films exposed to known doses. In most cases only one calibrated exposure was required since the dose for one of the films could be zero. Using the Gamma test criterion of 2%∕2 mm to evaluate the measurements, similar passing rates ranging between about 95% and 99% for the fields studied were obtained from application films digitized under a variety of conditions all of them different than the conditions under which the calibration films were scanned. CONCLUSIONS The authors have developed a simplified and efficient protocol to measure doses delivered by an IMRT or VMAT plan using only the patient film, one calibration film, one unexposed film, and applying a single scan to acquire a digital image for calculation and analysis. The simplification and timesaving offer a potential practical solution for using radiochromic film for routine treatment plan quality assurance without sacrificing spatial resolution for convenience.
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Affiliation(s)
- David Lewis
- Advanced Materials Group, Ashland Inc., Wayne, NJ 07470, USA
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Chan MF, Chiu-Tsao ST, Li J, Schupak K, Parhar P, Burman C. Confirmation of Skin Doses Resulting from Bolus Effect of Intervening Alpha-cradle and Carbon Fiber Couch in Radiotherapy. Technol Cancer Res Treat 2012; 11:571-81. [PMID: 22712603 DOI: 10.7785/tcrt.2012.500269] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, we verified the treatment planning calculations of skin doses with the incorporation of the bolus effect due to the intervening alpha-cradle (AC) and carbon fiber couch (CFC) using radiochromic EBT2 films. A polystyrene phantom (25 × 25 × 15 cm3) with six EBT2 films separated by polystyrene slabs, at depths of 0, 0.1, 0.2, 0.5, 1, 1.4 cm, was positioned above an AC, which was ~1 cm thick. The phantom and AC assembly were CT scanned and the CT-images were transferred to the treatment planning system (TPS) for calculations in three scenarios: (A) ignoring AC and CFC, (B) accounting for AC only, (C) accounting for both AC and CFC. A single posterior 10 × 10 cm2 field, a pair of posterior-oblique 10 × 10 cm2 fields, and a posterior IMRT field (6 MV photons from a Varian Trilogy linac) were planned. For each radiation field configuration, the same MU were used in all three scenarios in the TPS. Each plan for scenario C was delivered to expose a stack of EBT2 films in the phantom through AC and CFC. In addition, in vivo EBT2 film measurement on a lung cancer patient immobilized with AC undergoing IMRT was also included in this study. Point doses and planar distributions generated from the TPS for the three scenarios were compared with the data from the EBT2 film measurements. For all the field arrangements, the EBT2 film data including the in vivo measurement agreed with the doses calculated for scenario (C), within the uncertainty of the EBT2 measurements (~4%). For the single posterior field (a pair of posterior-oblique fields), the TPS generated doses were lower than the EBT2 doses by 34%, 33%, 31%, 13% (34%, 31%, 31%, 11%) for scenario A and by 27%, 25%, 22%, 8% (25%, 21%, 21%, 6%) for scenario B at the depths of 0, 0.1, 0.2, 0.5 cm, respectively. For the IMRT field, the 2D dose distributions at each depth calculated in scenario C agree with those measured data. When comparing the central axis doses for the IMRT field, we found the TPS generated doses for scenario A (B) were lower than the EBT2 data by 35%, 34%, 31%, 16% (29%, 26%, 23%, 10%) at the depths of 0, 0.1, 0.2, 0.5 cm, respectively. There were no significant differences for the depths of 1.0 and 1.4 cm for all the radiation fields studied. TPS calculation of doses in the skin layers accounting for AC and CFC was verified by EBT2 film data. Ignoring the presence of AC and/or CFC in TPS calculation would significantly underestimate the doses in the skin layers. For the clinicians, as more hypofractionated regimens and stereotactic regimens are being used, this information will be useful to avoid potential serious skin toxicities, and also assist in clinical decisions and report these doses accurately to relevant clinical trials/cooperative groups, such as RTOG.
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Affiliation(s)
- Maria F. Chan
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 136 Mountain View Blvd., Basking Ridge, NJ 07920, USA
| | | | - Jingdong Li
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 136 Mountain View Blvd., Basking Ridge, NJ 07920, USA
| | - Karen Schupak
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 136 Mountain View Blvd., Basking Ridge, NJ 07920, USA
| | - Preeti Parhar
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 136 Mountain View Blvd., Basking Ridge, NJ 07920, USA
| | - Chandra Burman
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 136 Mountain View Blvd., Basking Ridge, NJ 07920, USA
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Estimating dose to implantable cardioverter-defibrillator outside the treatment fields using a skin QED diode, optically stimulated luminescent dosimeters, and LiF thermoluminescent dosimeters. Med Dosim 2012; 37:334-8. [DOI: 10.1016/j.meddos.2011.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 09/16/2011] [Accepted: 11/08/2011] [Indexed: 11/19/2022]
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Kim JH, Hill R, Kuncic Z. An evaluation of calculation parameters in the EGSnrc/BEAMnrc Monte Carlo codes and their effect on surface dose calculation. Phys Med Biol 2012; 57:N267-78. [DOI: 10.1088/0031-9155/57/14/n267] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Chan MF, Zhang Q, Li J, Parhar P, Schupak K, Burman C. The Verification of iPlan Commissioning by Radiochromic EBT2 Films. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ijmpcero.2012.11001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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De Puysseleyr A, Srivastava RP, Paelinck L, De Neve W, De Wagter C. Evaluation of a glassless photographic film scanner for high-gradient radiochromic film dosimetry. Phys Med Biol 2011; 57:127-42. [DOI: 10.1088/0031-9155/57/1/127] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Beyer GP, Kry SF, Espenhahn E, Rini C, Boyles E, Mann G. Evaluation of an implantable MOSFET dosimeter designed for use with hypofractionated external beam treatments and its applications for breast and prostate treatments. Med Phys 2011; 38:4881-7. [PMID: 21928659 DOI: 10.1118/1.3615162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE An implantable metal-oxide semiconductor field effect transistors-based dosimeter has recently been developed for the in vivo monitoring of hypofractionated radiotherapy. This DVS-HFT dosimeter is designed for fraction sizes of 340-950 cGy and can also be used for bis in die fraction monitoring. The current work reports on the testing and evaluation of this dosimeter, including both its basic characteristics as well as its performance during simulated clinical treatment plans. METHODS The authors tested the dose rate dependence of this dosimeter (300 MU/min versus 600 MU/min), the treatment time dependence (4 min per treatment versus up to 60 min per treatment), and the dose and energy dependence (6 and 18 MV irradiations of 700-900 cGy per fraction). Additionally, they irradiated the detectors in-phantom with breast and prostate hypofractionated treatments. RESULTS The detectors showed no significant dose rate, treatment time, energy, or dose dependence. Furthermore, the detectors were found to perform within manufacturer tolerances for all hypofractionated treatments examined, accurately reporting the measured dose (average disagreement of - 0.65%). CONCLUSIONS These dosimeters appear well suited for in vivo monitoring of hypofractionated radiotherapy doses, and thereby, have the potential to improve patient care.
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Affiliation(s)
- Gloria P Beyer
- Medical Physics Services, LLC., Tampa, Florida 33606, USA.
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Kelly A, Hardcastle N, Metcalfe P, Cutajar D, Quinn A, Foo K, Cardoso M, Barlin S, Rosenfeld A. Surface dosimetry for breast radiotherapy in the presence of immobilization cast material. Phys Med Biol 2011; 56:1001-13. [DOI: 10.1088/0031-9155/56/4/008] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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