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Wesolowska P, Slusarczyk-Kacprzyk W, Fillmann M, Kazantsev P, Bulski W. Results of the IAEA supported national end-to-end audit of the IMRT technique in Poland. Phys Med 2023; 116:103168. [PMID: 37984129 DOI: 10.1016/j.ejmp.2023.103168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 10/09/2023] [Accepted: 11/05/2023] [Indexed: 11/22/2023] Open
Abstract
The dosimetry audit services were established in Poland in 1991, since then new audits have been introduced. The recently developed IAEA audit methodology for IMRT H&N treatments was tested nationally. Anthropomorphic SHANE phantom (CIRS) was used to perform measurements in 8 hospitals which voluntarily participated in the study. Each participant had to complete successfully pre-visit activities to take part in an onsite visit. During the visit, auditors together with the local staff, did a CT scan using local protocol, recalculated the plan and verified all the relevant parameters and performed measurements with an ionization chamber and films in SHANE. The adoption of IAEA methodology to the national circumstances was done with no major issues. Participants plans were verified and the results of ionization chamber were all within the 5 % tolerance limit for PTV (max 4,5%) and 7 % for OAR (max 5,3%). Film global gamma results (3 %, 3 mm, 90 % acceptance limit) were within 91,5-99,7% range. The IAEA established acceptance criteria which were achievable for most tests except for CTtoRED conversion curve. The locally performed study allowed establishing new limits. The audit gave interesting results and showed that the procedure is very thorough and capable to identify issues related with suboptimal treatment preparation and delivery. The new limits for CTtoRED conversion curve were adopted for national study. Such an audit gives an opportunity to verify the quality of locally implemented procedures and should be available for Polish hospitals on a daily basis.
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Affiliation(s)
- Paulina Wesolowska
- Department of Medical Physics, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland.
| | | | - Marta Fillmann
- Department of Medical Physics, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Pavel Kazantsev
- Dosimetry Laboratory, Dosimetry and Medical Radiation Physics Section, Division of Human Health, International Atomic Energy Agency, Vienna, Austria
| | - Wojciech Bulski
- Department of Medical Physics, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
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2
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Shaw M, Lye J, Alves A, Lehmann J, Sanagou M, Geso M, Brown R. Measuring dose in lung identifies peripheral tumour dose inaccuracy in SBRT audit. Phys Med 2023; 112:102632. [PMID: 37406592 DOI: 10.1016/j.ejmp.2023.102632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/25/2023] [Accepted: 06/21/2023] [Indexed: 07/07/2023] Open
Abstract
PURPOSE Stereotactic Body Radiotherapy (SBRT) for lung tumours has become a mainstay of clinical practice worldwide. Measurements in anthropomorphic phantoms enable verification of patient dose in clinically realistic scenarios. Correction factors for reporting dose to the tissue equivalent materials in a lung phantom are presented in the context of a national dosimetry audit for SBRT. Analysis of dosimetry audit results is performed showing inaccuracies of common dose calculation algorithms in soft tissue lung target, inhale lung material and at tissue interfaces. METHODS Monte Carlo based simulation of correction factors for detectors in non-water tissue was performed for the soft tissue lung target and inhale lung materials of a modified CIRS SBRT thorax phantom. The corrections were determined for Gafchromic EBT3 Film and PTW 60019 microDiamond detectors used for measurements of 168 SBRT lung plans in an end-to-end dosimetry audit. Corrections were derived for dose to medium (Dm,m) and dose to water (Dw,w) scenarios. RESULTS Correction factors were up to -3.4% and 9.2% for in field and out of field lung respectively. Overall, application of the correction factors improved the measurement-to-plan dose discrepancy. For the soft tissue lung target, agreement between planned and measured dose was within average of 3% for both film and microDiamond measurements. CONCLUSIONS The correction factors developed for this work are provided for clinical users to apply to commissioning measurements using a commercially available thorax phantom where inhomogeneity is present. The end-to-end dosimetry audit demonstrates dose calculation algorithms can underestimate dose at lung tumour/lung tissue interfaces by an average of 2-5%.
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Affiliation(s)
- Maddison Shaw
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia; School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia.
| | - Jessica Lye
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia; Olivia Newton John Cancer Wellness and Research Centre, Austin Health, Australia
| | - Andrew Alves
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| | - Joerg Lehmann
- Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, Australia; School of Science, RMIT University, Melbourne, Australia; School of Mathematical and Physical Sciences, University of Newcastle, Australia; Institute of Medical Physics, University of Sydney, Australia
| | - Masoumeh Sanagou
- Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
| | - Moshi Geso
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia
| | - Rhonda Brown
- Australian Clinical Dosimetry Service, Australian Radiation Protection and Nuclear Safety Agency, Melbourne, Australia
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Zeinali A, Molazadeh M, Ganjgahi S, Saberi H. Collapsed Cone Superposition Algorithm Validation for Chest Wall Tangential Fields using Virtual Wedge Filters. J Med Signals Sens 2023; 13:191-198. [PMID: 37622042 PMCID: PMC10445677 DOI: 10.4103/jmss.jmss_7_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 12/31/2022] [Accepted: 03/13/2023] [Indexed: 08/26/2023]
Abstract
Background Virtual wedge (VW) is used in radiotherapy to compensate for missing tissues and create a uniform dose distribution in tissues. According to TECDOC-1583 and technical reports series no. 430, evaluating the dose calculation accuracy is essential for the quality assurance of treatment planning systems (TPSs). In this study, the dose calculation accuracy of the collapsed cone superposition (CCS) algorithm in the postmastectomy radiotherapy of the chest wall for breast cancer was evaluated by comparing the calculated and measured dose in VW fields. Methods Two tangential fields with the typical VW angles were planned using ISOgray TPS in a thorax phantom. The CCS algorithm was used for dose calculation at 6 and 15 MV photon beams. The obtained dose distributions from EBT3 film spaces and TPS were evaluated using the gamma index. Results The measured and calculated dose values using VW in a heterogeneous medium with different beam energies were in a good agreement with each other (acceptance rate: 88.0%-93.4%). The calculated and measured data did not differ significantly with an increase/decrease in wedge angle. In addition, the results demonstrated that ISOgray overestimated and underestimated the dose of the soft tissue and lung in the planned volume, respectively. Conclusions According to the results of gamma index analysis, the calculated dose distribution using VW model with the CCS algorithm in a heterogeneous environment was within acceptable limits.
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Affiliation(s)
- Ahad Zeinali
- Department of Medical Physics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Mikaeil Molazadeh
- Department of Medical Physics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Samaneh Ganjgahi
- Department of Medical Physics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Hassan Saberi
- Department of Medical Physics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
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Walter AE, Khan AU, DeWerd LA. Measurement of the modified TG43 parameters for the bare S7600 Xoft Axxent source model. Brachytherapy 2023; 22:260-268. [PMID: 36623989 DOI: 10.1016/j.brachy.2022.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 11/16/2022] [Accepted: 11/22/2022] [Indexed: 01/09/2023]
Abstract
PURPOSE The purpose of this work is to provide measured data for the modified TG43 parameters [DeWerd et al.] for the newest, Galden-cooled S7600 Xoft Axxent source model. METHODS The measurement of radial dose distributions at distances of 1 cm to 4 cm from the source was performed using TLD100 microcubes, EBT3 film, and an Exradin A26 microionization chamber. The overall uncertainty and reproducibility of each dosimeter was evaluated for its use in determining the radial dose function and dose rate conversion coefficient. An acrylic phantom developed in house for previous works was used to measure the polar anisotropy function using TLD100 microcubes at distances of 1 cm, 2 cm, and 5 cm from the source. RESULTS The Exradin A26 chamber was deemed most suitable for measuring the radial dose function. Values determined had a maximum k = 1 uncertainty of 1.4%. The dose rate conversion coefficient measured with the chamber was found to be 9.33 ± 0.21cGy/hrμGy/min. TLD100 microcube measurements of the polar anisotropy had average uncertainties of 6%, 3%, and 2.5% at 1 cm, 2 cm, and 5 cm, respectively. CONCLUSIONS The modified TG43 parameters for the bare source were measured with reasonable uncertainty. The values determined will aid with the clinical implementation of the source for breast and endometrial cancer applications.
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Affiliation(s)
- Autumn E Walter
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI; Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin, Madison, WI.
| | - Ahtesham U Khan
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI
| | - Larry A DeWerd
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, Madison, WI
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Hosseini FS, Baghani HR, Robatjazi M, Mowlavi AA, Porouhan P. Performance evaluation of buildup bolus during external radiotherapy of mastectomy patients: treatment planning and film dosimetry. Med Biol Eng Comput 2023; 61:435-444. [PMID: 36460872 DOI: 10.1007/s11517-022-02721-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/19/2022] [Indexed: 12/04/2022]
Abstract
A buildup bolus is used during the post-mastectomy radiotherapy (PMRT) to overcome under-dosage issues in the chest wall. The current study is aimed at evaluating the performance of a bolus in dose enhancement through both film dosimetry and treatment planning approaches. Twenty patients were enrolled in current research. The received dose by the skin at the lateral and medial regions of the chest wall in the presence and absence bolus was evaluated. Film dosimetry results showed that the presence of the bolus can averagely increase the skin dose by about 80% (P value < 0.001) and 92% (P value < 0.001) in lateral and medial regions, respectively. No significant difference was observed between the measured and treatment planning system (TPS)-calculated dose values in the presence of bolus. The presence of the bolus can considerably increase the absorbed dose by superficial chest wall regions. The TPS shows a favorable performance in superficial dose calculations in the presence of the buildup bolus. Hosseini et al.: demonstration of implemented research in the current study.
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Affiliation(s)
| | | | - Mostafa Robatjazi
- Medical Physics and Radiological Sciences Department, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | | | - Pejman Porouhan
- Radiation Oncology Department, Sabzevar University of Medical Sciences, Sabzevar, Iran
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Boh Lim S, Tyagi N, Subashi E, Liang J, Chan M. An evaluation of the use of EBT-XD film for SRS/SBRT commissioning of a 1.5 Tesla MR-Linac system. Phys Med 2022; 96:9-17. [PMID: 35189431 PMCID: PMC9396448 DOI: 10.1016/j.ejmp.2022.02.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/06/2022] [Accepted: 02/12/2022] [Indexed: 11/26/2022] Open
Abstract
Purpose: The goal of this study was to evaluate the use of EBT-XD film for SRS/SBRT commissioning in a 1.5T hybrid MR-Linac (MRL). Method: The output factors (St), from 1x1, 2x2, 3x3 cm2, were measured with film in solid water. The results were compared with (1) the measurements by a PTW diamond detector (CVD) and an Exradin® A26MR ion chamber in 3D water phantom; (2) Monte Carlo calculation by Monaco TPS (MTPS) in water. The inline (IN) and crossline (CR) profiles, measured by films and the CVD, were also compared. An SRS plan with two targets was created in MTPS and was measured with EBT-XD film in a StereoPHAN™ phantom serving as an end-to-end test. The 3x3 cm2 was used for film calibration with doses ranging from 0 to 28 Gy. Water was added to the phantom-film-phantom interface to reduce the electron-return-effect (ERE). Films were calibrated with One-scan-dosimetry protocol. Results: The film St were within 1.2% and 2.2% compared to other detectors and MTPS respectively. At the central B-field induced asymmetric region, films were within 0.6% between the CVD and the MTPS, but 5–8% differences were observed in the 40%-5% gradient region in CR due to ERE. The differences in localization and dose were found to be 0.6 mm and 3.3%. The γ(3%/2mm), γ (5%/2mm), γ (5%/1mm) were 97.7%, 99.3%, 94.6%. Conclusions: Films can provide accurate dosimetric results under ERE and are valuable for commissioning MRL. Using the One-scan-dosimetry protocol with EBT-XD film for MRL increases accuracy and efficiency in commissioning and QA of SRS/SBRT.
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Affiliation(s)
- Seng Boh Lim
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, United States.
| | - Neelam Tyagi
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, United States.
| | - Ergys Subashi
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, United States.
| | - Jiayi Liang
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, United States.
| | - Maria Chan
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, United States.
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7
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Khaleghi G, Mahdavi H, Mahdavi SR, Khajetash B, Nikoofar A, Hosntalab M, Sadeghi M, Reiazi R. Investigating dose homogeneity in radiotherapy of oral cancers in the presence of a dental implant system: an in vitro phantom study. Int J Implant Dent 2021; 7:90. [PMID: 34486092 PMCID: PMC8419140 DOI: 10.1186/s40729-021-00372-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 06/27/2021] [Indexed: 11/17/2022] Open
Abstract
Background Materials with high atomic numbers are part of the composition of dental implant systems. In radiotherapy of oral cavity cancers, an implant can cause dose perturbations that affect target definition, dose calculation, and dose distribution. In consequence, this may result in poor tumor control and higher complications. In this study, we evaluated dose homogeneity when a dental implant replaced a normal tooth. We also aimed to evaluate the concordance of dose calculations with dose measurements. Materials and methods In this study, 2 sets of planning CT scans of a phantom with a normal tooth and the same phantom with the tooth replaced by a Z1 TBR dental implant system were used. The implant system was composed of a porcelain-fused-to-metal crown and titanium with a zirconium collar. Three radiotherapy plans were designed when the density of the implant material was corrected to match their elements, or when all were set to the density of water, or when using the default density conversion. Gafchromic EBT-3 films at the level of isocenter and crowns were used for measurements. Results At the level of crowns, upstream and downstream dose calculations were reduced when metal kernels were applied (M-plan). Moreover, relatively measured dose distribution patterns were most similar to M-plan. At this level, relative to the non-implanted phantom, mean doses values were higher with the implant (215.93 vs. 192.25), also, new high-dose areas appeared around a low-dose streak forward to the implant (119% vs. 95%). Conclusions Implants can cause a high dose to the oral cavity in radiotherapy because of extra scattered radiation. Knowledge of the implant dimensions and defining their material enhances the accuracy of calculations.
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Affiliation(s)
- Goli Khaleghi
- Medical Radiation Engineering Department, Science and Research Branch, Islamic Azad University, Daneshgah Blvd., Simon Bolivar Blvd., P.O. Box: 14515-775, Tehran, Iran
| | - Hoda Mahdavi
- Radiation Biology Research Center, Iran University of Medical Sciences, Shahid Hemmat Highway, P.O. Box: 14665-354, Tehran, Iran. .,Radiation Oncology Department, Iran University of Medical Sciences, Firoozgar hospital, Beh-Afarin St., Karimkhane-Zand Blvd., P.O. Box: 1593747811, Tehran, Iran.
| | - Seied Rabi Mahdavi
- Radiation Biology Research Center, Iran University of Medical Sciences, Shahid Hemmat Highway, P.O. Box: 14665-354, Tehran, Iran.,Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Shahid Hemmat Highway, P.O. Box: 14155-6183, Tehran, Iran
| | - Benyamin Khajetash
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Shahid Hemmat Highway, P.O. Box: 14155-6183, Tehran, Iran
| | - Alireza Nikoofar
- Radiation Oncology Department, Iran University of Medical Sciences, Firoozgar hospital, Beh-Afarin St., Karimkhane-Zand Blvd., P.O. Box: 1593747811, Tehran, Iran
| | - Mohammad Hosntalab
- Medical Radiation Engineering Department, Science and Research Branch, Islamic Azad University, Daneshgah Blvd., Simon Bolivar Blvd., P.O. Box: 14515-775, Tehran, Iran
| | - Mahdi Sadeghi
- Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Shahid Hemmat Highway, P.O. Box: 14155-6183, Tehran, Iran
| | - Reza Reiazi
- Princess Margaret Cancer Center, University Health Network, 101 College Street, P.O. Box: M5G 1L7, Ontario, Toronto, Canada
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Laurans M, Kirov K, Costa E, Lefebvre D, Kirova YM. Clinical and dosimetric impact of totally implantable venous access devices in radiotherapy of supra diaphragmatic Hodgkin Lymphoma. Cancer Radiother 2021; 25:32-8. [PMID: 33402292 DOI: 10.1016/j.canrad.2020.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 05/25/2020] [Accepted: 05/27/2020] [Indexed: 11/21/2022]
Abstract
PURPOSE To evaluate attenuation of the totally implantable vascular access device (TIVAD) and assess its clinical and dosimetric impact on radiotherapy (RT) of lymphoma patients. MATERIALS AND METHODS The first part of the study consisted of an in vitro approach by irradiating the TIVAD with different electron and photon energies. The attenuation data measured were compared with data calculated by our treatment planning system. All patients treated by radiotherapy for Hodgkin's lymphoma with their TIVAD in the target volume were then reviewed to assess the clinical outcome and dosimetric comparison using different plan metrics. All patients were treated by 3D conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy delivered by Helical Tomotherapy (HT). RESULTS Nineteen patients treated for stage I-III HL were studied. Seven patients were treated exclusively on the side of TIVAD and 12 were treated bilaterally. Median prescription dose was 30Gy. No significant clinical or dosimetric differences were observed between the side of the TIVAD and the contralateral side in patients treated bilaterally. HT resulted in a significantly higher conformity index (P<0.0022) and a significantly lower healthy tissue coverage (P=0.0008) than 3DCRT. The observed attenuation was 79% for 6 MeV, 59% for 9 MeV, and 46% for 12 MeV for electrons and 9% for 4 MV, 8% for 6 MV, 5% for 10 MV and 15 MV and 3% for 20 MV for X photons. CONCLUSION TIVADs induce significant beam attenuation when using electrons, which can be overcome by using high-energy photons or by creating an exclusion zone in when HT is used.
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Hur BI, Jin SJ, Kim GR, Kwak JH, Kim YH, Lee SW, Sung SK. Validation of Gamma Knife Perfexion Dose Profile Distribution by a Modified Variable Ellipsoid Modeling Technique. J Korean Neurosurg Soc 2021; 64:13-22. [PMID: 33465847 PMCID: PMC7819799 DOI: 10.3340/jkns.2020.0186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 12/15/2020] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE High precision and accuracy are expected in gamma knife radiosurgery treatment. Because of the requirement of clinically applying complex radiation and dose gradients together with a rapid radiation decline, a dedicated quality assurance program is required to maintain the radiation dosimetry and geometric accuracy and to reduce all associated risk factors. This study investigates the validity of Leksell Gamma plan (LGP)10.1.1 system of 5th generation Gamma Knife Perfexion as modified variable ellipsoid modeling technique (VEMT) method. METHODS To verify LGP10.1.1 system, we compare the treatment plan program system of the Gamma Knife Perfexion, that is, the LGP, with the calculated value of the proposed modified VEMT program. To verify a modified VEMT method, we compare the distributions of the dose of Gamma Knife Perfexion measured by Gafchromic EBT3 and EBT-XD films. For verification, the center of an 80 mm radius solid water phantom is placed in the center of all sectors positioned at 16 mm, 4 mm and 8 mm; that is, the dose distribution is similar to the method used in the x, y, and z directions by the VEMT. The dose distribution in the axial direction is compared and analyzed based on Full-Width-of-Half-Maximum (FWHM) evaluation. RESULTS The dose profile distribution was evaluated by FWHM, and it showed an average difference of 0.104 mm for the LGP value and 0.130 mm for the EBT-XD film. CONCLUSION The modified VEMT yielded consistent results in the two processes. The use of the modified VEMT as a verification tool can enable the system to stably test and operate the Gamma Knife Perfexion treatment planning system.
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Affiliation(s)
- Beong Ik Hur
- Department of Neurosurgery, Pusan National University Hospital, Busan, Korea
| | - Seong Jin Jin
- Gamma-knife Center, Haeundae Paik Hospital, Inje University, Busan, Korea
| | - Gyeong Rip Kim
- Gamma-knife Center, Pusan National University Yangsan Hospital, Yangsan, Korea.,Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Jong Hyeok Kwak
- Department of Radiology, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Young Ha Kim
- Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Sang Weon Lee
- Gamma-knife Center, Pusan National University Yangsan Hospital, Yangsan, Korea.,Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea
| | - Soon Ki Sung
- Gamma-knife Center, Pusan National University Yangsan Hospital, Yangsan, Korea.,Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea
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Shameem T, Bennie N, Butson M, Thwaites D. A comparison between EPSON V700 and EPSON V800 scanners for film dosimetry. Australas Phys Eng Sci Med 2020; 43:10.1007/s13246-019-00837-3. [PMID: 31912461 DOI: 10.1007/s13246-019-00837-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 12/16/2019] [Indexed: 11/29/2022]
Abstract
Radiochromic film is a good dosimeter choice for patient QA for complex treatment techniques (IMRT, VMAT, SABR, SBRT) because of its near tissue equivalency, very high spatial resolution and established method of use. Commercial scanners are usually used for film dosimetry, among which EPSON scanners are the most common. NCCI have used an EPSON V700 scanner, but recently acquired a new model EPSON V800 scanner. The purpose of this work was to evaluate any differences between these two scanners to consider whether they can be used interchangeably or not. Different aspects of film dosimetry, e.g. lateral response artefact (LRA) effect, orientation effect, scanner response etc., were compared. EBT3 films were irradiated with 40 × 40 cm2 field size 6 MV beams and scanned in both the scanners. The scanned images were read in ImageJ V1.49 software. The data obtained was then copied in MS Excel to compare the scanners. The V800 scanner causes more polarisation, which results in more LRA effect than for the V700 scanner. The responses of the scanners in all three colour channels are not the same for the same film and irradiation. The V800 scanner shows an increase of response of up to 1.6% compared to 3.7% increase in the V700 scanner after scanning a piece of irradiated film 20 times. The scanners cannot be used interchangeably. The correction factors for LRA effect and the calibration curves are different. Further characterisation, evaluation and commissioning is required before clinical use.
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Affiliation(s)
- Tarafder Shameem
- North Coast Cancer Institute, Lismore, NSW, Australia.
- School of Physics, Institute of Medical Physics, University of Sydney, Sydney, NSW, Australia.
| | - Nick Bennie
- North Coast Cancer Institute, Lismore, NSW, Australia
| | - Martin Butson
- School of Physics, Institute of Medical Physics, University of Sydney, Sydney, NSW, Australia
- Department of Radiation Oncology, Chris O'Brien Lifehouse, Sydney, NSW, Australia
| | - David Thwaites
- School of Physics, Institute of Medical Physics, University of Sydney, Sydney, NSW, Australia
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Magnier F, Poulin M, Van Ngoc Ty C, Osmond E, Bonniaud G, Coulot J, Pereira B, Boyer L, Guersen J, Cassagnes L. Comparison of Patient Skin Dose Evaluated Using Radiochromic Film and Dose Calculation Software. Cardiovasc Intervent Radiol 2018; 41:762-771. [PMID: 29417266 DOI: 10.1007/s00270-018-1888-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 01/22/2018] [Indexed: 10/18/2022]
Abstract
PURPOSE To compare, in an interventional radiology setting, peak skin doses (PSDs) delivered as calculated using a dedicated software tool and as measured using radiochromic film. To assess the utility of this dose calculation software tool in routine clinical practice. MATERIALS AND METHODS First, radiochromic films were positioned on the examination table in the back of an adult anthropomorphic phantom to measure PSD, and X-ray examinations were simulated. Then, films were again positioned in the patient's back for 59 thoracic or abdominopelvic endovascular interventions. The results obtained with the radiochromic films were taken as a reference and were statistically compared with those of the software. RESULTS With measured PSDs ranging from 100 to 7000 mGy, the median software-film difference was 8.5%. Lin's concordance coefficient was 0.98 [0.97; 0.99] (p < 0.001), meaning that concordance was excellent between the two methods. For the films where PSD exceeded 1000 mGy, the median difference in the measured value was 8.7% [- 1.3; 21.1], with a maximum discrepancy of 34%. Lin's concordance coefficient was 0.98 [0.96; 1] (p < 0.001), meaning that concordance was excellent between the two methods. CONCLUSION Comparison between radiochromic films and the software tool showed that the software is a suitable tool for a simple and reliable estimation of PSD. The software seems to be a good alternative to films, whose use remains complex.
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Affiliation(s)
- Florian Magnier
- Pôle d'Imagerie Diagnostique et de Radiologie Interventionnelle, CHU, 63003, Clermont-Ferrand, France. .,Plateforme régionale de physique médicale, Centre Jean Perrin, 63011, Clermont-Ferrand, France.
| | - Maxime Poulin
- Pôle d'Imagerie Diagnostique et de Radiologie Interventionnelle, CHU, 63003, Clermont-Ferrand, France
| | | | - Estelle Osmond
- Pôle d'Imagerie Diagnostique et de Radiologie Interventionnelle, CHU, 63003, Clermont-Ferrand, France
| | | | | | - Bruno Pereira
- Biostatistics Unit (Délégation Recherche Clinique & Innovation), CHU, 63003, Clermont-Ferrand, France
| | - Louis Boyer
- Pôle d'Imagerie Diagnostique et de Radiologie Interventionnelle, CHU, 63003, Clermont-Ferrand, France.,ISIT, UMR 6284 CNRS, Université d'Auvergne, 63001, Clermont-Ferrand, France
| | - Joel Guersen
- Pôle d'Imagerie Diagnostique et de Radiologie Interventionnelle, CHU, 63003, Clermont-Ferrand, France
| | - Lucie Cassagnes
- Pôle d'Imagerie Diagnostique et de Radiologie Interventionnelle, CHU, 63003, Clermont-Ferrand, France.,ISIT, UMR 6284 CNRS, Université d'Auvergne, 63001, Clermont-Ferrand, France
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12
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Boman EL, Satherley TWS, Schleich N, Paterson DB, Greig L, Louwe RJW. The validity of Acuros BV and TG-43 for high-dose-rate brachytherapy superficial mold treatments. Brachytherapy 2017; 16:1280-1288. [PMID: 28967561 DOI: 10.1016/j.brachy.2017.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 08/16/2017] [Accepted: 08/18/2017] [Indexed: 12/20/2022]
Abstract
PURPOSE The purpose of this work is to validate the Acuros BV dose calculation algorithm for high-dose-rate (HDR) brachytherapy superficial mold treatments in the absence of full scatter conditions and compare this with TG-43 dose calculations. We also investigate the impact of additional back scatter material (bolus) applied above surface molds to the dose distributions under the mold. METHODS AND MATERIALS The absorbed dose at various depths was compared for simulations performed using either TG-43 or Acuros BV dose calculations. Parameter variations included treatment area, thickness of the bolus, and surface shape (flat or spherical). Film measurements were carried out in a flat phantom. RESULTS Acuros BV calculations and film measurements agreed within 1.5% but were up to 15% lower than TG-43 dose calculations when no bolus was applied above the treatment catheters. The difference in dose at the prescription depth (1 cm below the central catheter) increased with increasing treatment area: 3.3% difference for a 3 × 3.5 cm2 source loading area, 7.4% for 8 × 9 cm2, and 13.4% for 18 × 19 cm2. The dose overestimation of the TG-43 model decreased when bolus was added above the treatment catheters. CONCLUSIONS The TG-43 dosimetry formalism cannot model surface mold treatments in the absence of full scatter conditions within 5% for loading areas larger than approximately 5 × 5 cm2. The TG-43 model results in an overestimation of the delivered dose, which increases with treatment area. This confirms the need for model-based dose calculation algorithms as discussed in TG-186.
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Affiliation(s)
- Eeva L Boman
- Blood & Cancer Centre, Wellington Hospital, Wellington, NZ; Department of Oncology, Tampere University Hospital, Tampere, Finland; Department of Medical Physics, Tampere University Hospital, Tampere, Finland.
| | | | | | | | - Lynne Greig
- Blood & Cancer Centre, Wellington Hospital, Wellington, NZ
| | - Rob J W Louwe
- Blood & Cancer Centre, Wellington Hospital, Wellington, NZ
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13
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Peterlin P, Stanič K, Méndez I, Strojnik A. Treating lung cancer with dynamic conformal arc therapy: a dosimetric study. Radiat Oncol 2017; 12:93. [PMID: 28578699 PMCID: PMC5457634 DOI: 10.1186/s13014-017-0823-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 05/16/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Lung cancer patients are often in poor physical condition, and a shorter treatment time would reduce their discomfort. Dynamic conformal arc therapy (DCAT) offers a shorter treatment time than conventional 3D conformal radiotherapy (3D CRT) and is usually available even in departments without inverse planning possibilities. We examined its suitability as a treatment modality for lung cancer patients. METHODS On a cohort of 35 lung cancer patients, relevant dosimetric parameters were compared in respective DCAT and 3D CRT treatment plans. Radiochromic film dosimetry in an anthropomorphic phantom was used to compare both DCAT and 3D CRT dose distributions against their planned counterparts. RESULTS In comparison with their 3D CRT counterparts, DCAT plans equal or exceed the agreement between the calculated dose and the dose measured using film dosimetry. In dosimetric comparison, DCAT performed significantly better than 3D CRT in dose conformity to PTV and the number of monitor units used per plan, and significantly worse in dose homogeneity, mean lung dose and lung volume exposed to 5 Gy or more (V5Gy). No significant difference was found in the V20Gy value to lung, dose to 1 cm3 of spinal cord, and the mean dose to oesophagus. Improvements in V20Gy and V5Gy were found to be negatively correlated. DCAT plans differ from 3D CRT by exhibiting a moderate negative correlation between target volume sphericity and dose homogeneity. CONCLUSIONS With respect to the agreement between the planned and the irradiated dose distribution, DCAT appears at least as reliable as 3D CRT. In specific conditions concerning the patient anatomy and treatment prescription, DCAT may yield more favourable dosimetric parameters. On average, however, conventional 3D CRT usually obtains better dosimetric parameters. We can thus only recommend DCAT as a complementary technique to the conventional 3D CRT.
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Affiliation(s)
- Primož Peterlin
- Institute of Oncology Ljubljana, Zaloška 2, Ljubljana, SI-1000, Slovenia.
| | - Karmen Stanič
- Institute of Oncology Ljubljana, Zaloška 2, Ljubljana, SI-1000, Slovenia
| | - Ignasi Méndez
- Institute of Oncology Ljubljana, Zaloška 2, Ljubljana, SI-1000, Slovenia
| | - Andrej Strojnik
- Institute of Oncology Ljubljana, Zaloška 2, Ljubljana, SI-1000, Slovenia
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14
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Vera Sánchez JA, Ruiz Morales C, González López A. Characterization of noise and digitizer response variability in radiochromic film dosimetry. Impact on treatment verification. Phys Med 2016; 32:1167-74. [PMID: 27595366 DOI: 10.1016/j.ejmp.2016.08.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 08/21/2016] [Accepted: 08/23/2016] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To study how noise and scanner response variability affect radiochromic film dosimetry. METHODS Five treatment plans were analyzed in this work with two different multichannel protocols: the multichannel algorithm of Mayer et al. and the efficient protocol of Lewis et al. RESULTS AND CONCLUSION The multichannel protocol of Mayer et al. is not able to compensate variability in scanner response, which is an important issue for radiochromic film dosimetry. The efficient protocol compensates variations of scanner response, so dose values and gamma scores become more accurate and reproducible. The compensation of digitizer scan variability of the efficient protocol, together with time averaging improve radiochromic film dosimetry. Noise is related to selected resolution in the scanner, our results show that if high resolution measurements are required, de-noising should be considered.
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15
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Mori Y, Isobe T, Yamaguchi Y, Takei H, Kamizawa S, Terunuma T, Sato E, Takada K, Tadano K, Yoshimura Y, Sakurai H, Sakae T. Development of simple high-precision two-dimensional dose-distribution measurement method for proton beam therapy using imaging plate and EBT3. Australas Phys Eng Sci Med 2016; 39:687-96. [PMID: 27470695 DOI: 10.1007/s13246-016-0464-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 07/12/2016] [Indexed: 10/21/2022]
Abstract
Although there are several two-dimensional (2D) dose-distribution measurement methods using proton beam therapy, they all have drawbacks; hence, there is no standard method established worldwide. The purpose of this study was to develop a simple, high-precision 2D distribution measurement method for proton beam therapy that uses an imaging plate and EBT3. First, we expanded the maximum readable dose (saturation dose) in the imaging plate. The method involves (i) the control of the fading phenomenon by an annealing process and (ii) the control of the photostimulated luminescence (PSL) phenomenon using a longpass filter (LPF). In method (i), upon heating at 80 °C, the PSL became 0.485 times the room temperature, and in method (ii), we attenuated the PSL by a factor of 0.245 using an LPF. Thus, by combining methods (i) and (ii), we expanded the saturation dose to 2 Gy. Thus, it was possible to measure the imaging plate and EBT3 in the same dose range. We simultaneously measured the percent depth dose using imaging plate and EBT3. We defined a correction factor to match the measured values-which had a reduced sensitivity because of the linear energy transfer (LET) dependence of the imaging plate and EBT3-with reference data and developed a correction factor function. Subsequently, by defining the relative LET dependence of imaging plate and EBT3 as the relative sensitivity and converting the relationship imaging plate between the relative sensitivity and correction factor into a function, we obtained a sensitivity-correction function. By employing this function, measurements with the same accuracy as the reference data were performed using the imaging plate and EBT3.
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16
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Gholami S, Mirzaei HR, Jabbary Arfaee A, Jaberi R, Nedaie HA, Rabi Mahdavi S, Rajab Bolookat E, Meigooni AS. Dose distribution verification for GYN brachytherapy using EBT Gafchromic film and TG-43 calculation. Rep Pract Oncol Radiother 2016; 21:480-6. [PMID: 27489519 DOI: 10.1016/j.rpor.2016.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 01/20/2016] [Accepted: 06/26/2016] [Indexed: 12/01/2022] Open
Abstract
AIM Verification of dose distributions for gynecological (GYN) brachytherapy implants using EBT Gafchromic film. BACKGROUND One major challenge in brachytherapy is to verify the accuracy of dose distributions calculated by a treatment planning system. MATERIALS AND METHODS A new phantom was designed and fabricated using 90 slabs of 18 cm × 16 cm × 0.2 cm Perspex to accommodate a tandem and Ovoid assembly, which is normally used for GYN brachytherapy treatment. This phantom design allows the use of EBT Gafchromic films for dosimetric verification of GYN implants with a cobalt-60 HDR system or a LDR Cs-137 system. Gafchromic films were exposed using a plan that was designed to deliver 1.5 Gy of dose to 0.5 cm distance from the lateral surface of ovoids from a pair of ovoid assembly that was used for treatment vaginal cuff. For a quantitative analysis of the results for both LDR and HDR systems, the measured dose values at several points of interests were compared with the calculated data from a commercially available treatment planning system. This planning system was utilizing the TG-43 formalism and parameters for calculation of dose distributions around a brachytherapy implant. RESULTS The results of these investigations indicated that the differences between the calculated and measured data at different points were ranging from 2.4% to 3.8% for the LDR Cs-137 and HDR Co-60 systems, respectively. CONCLUSION The EBT Gafchromic films combined with the newly designed phantom could be utilized for verification of the dose distributions around different GYN implants treated with either LDR or HDR brachytherapy procedures.
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Affiliation(s)
- Somayeh Gholami
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamid Reza Mirzaei
- Radiation Oncology Department, Shohada e Tajrish Hospital, Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Jabbary Arfaee
- Radiation Oncology Department, Shohada e Tajrish Hospital, Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ramin Jaberi
- Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Hassan Ali Nedaie
- Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Seied Rabi Mahdavi
- Department of Medical Physics, Iran University of Medical Sciences, Tehran, Iran
| | - Eftekhar Rajab Bolookat
- Radiation Oncology Department, Shohada e Tajrish Hospital, Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali S Meigooni
- Comprehensive Cancer Centers of Nevada, Las Vegas, NV, United States
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17
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Bahreyni Toosi M, Mohamadian N, Ghorbani M, Khorshidi F, Akbari F, Knaup C. Skin Dosimetry in Radiotherapy of Breast Cancer: a Comparison between EBT and EBT3 Radiochromic Films. J Biomed Phys Eng 2016; 6:51-60. [PMID: 27672625 PMCID: PMC5022755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 08/30/2015] [Indexed: 06/06/2023]
Abstract
OBJECTIVE Radiochromic EBT3 film is a later generation of radiochromic films. The aim of this study is to compare EBT and EBT3 radiochromic films in radiotherapy fields of breast cancer. METHODS A RANDO phantom was irradiated by a 6 MV Siemens Primus linac with medial and lateral fields of radiotherapy of breast cancer. Dosimetry was performed in various points in the fields using EBT and EBT3 films. Films were scanned by a Microtek color scanner. Dose values from two films in corresponding points were compared. RESULTS In the investigation of calibration, net optical density (NOD) of EBT radiochromic is more than the EBT3 radiochromic film. The highest percentage difference between NODs of two films is related to 0.75 Gy and equals to 14.19%. The lowest value is related to 0.2 Gy dose and is equal to 3.31%. The highest percentage difference between two films on the RANDO phantom in breast cancer fields is 13.51% and the minimum value is equal to 0.33%. CONCLUSION From the comparison between the two films, most of the points show differences in dose in the measurements in fields of breast cancer radiotherapy. These differences are attributed to the thickness of the active layers, the overall thickness of the films, and the difference in the calibration fitted functions. The advantage of EBT film over EBT3 is a higher sensitivity; on the other hand EBT3 film allows to use its both sides in the scanning process and it is a new version of this film type.
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Affiliation(s)
- M.T. Bahreyni Toosi
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - N. Mohamadian
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - M. Ghorbani
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - F. Khorshidi
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - F. Akbari
- Medical Physics Department, Reza Radiation Oncology Center, Mashhad, Iran
| | - C. Knaup
- Comprehensive Cancer Centers of Nevada, Las Vegas, NV, USA
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18
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Jin JY, Zhao B, Kaminski JM, Wen N, Huang Y, Vender J, Chetty IJ, Kong FM. A MLC-based inversely optimized 3D spatially fractionated grid radiotherapy technique. Radiother Oncol 2015; 117:483-6. [PMID: 26277434 DOI: 10.1016/j.radonc.2015.07.047] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 07/26/2015] [Accepted: 07/27/2015] [Indexed: 11/23/2022]
Abstract
This study presents a MLC-based, 3D grid-therapy technique with characteristics of both 3D-conformal-radiotherapy and grid-therapy. It generates a brachytherapy-like dose distribution, with D50% of 20, 9.8, 5.4 and 2.9-Gy, for the spheres, target, 1 cm-outershell and 2 cm-outershell, respectively. It may provide a strategy to deliver ablative doses to large tumors safely.
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19
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Gonzalez-Lopez A, Vera-Sanchez JA, Lago-Martin JD. Small fields measurements with radiochromic films. J Med Phys 2015; 40:61-7. [PMID: 26170551 PMCID: PMC4478646 DOI: 10.4103/0971-6203.158667] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 03/02/2015] [Accepted: 03/03/2015] [Indexed: 11/15/2022] Open
Abstract
The small fields in radiotherapy are widely used due to the development of techniques such as intensity-modulated radiotherapy and stereotactic radio surgery. The measurement of the dose distributions for small fields is a challenge. A perfect dosimeter should be independent of the radiation energy and the dose rate and should have a negligible volume effect. The radiochromic (RC) film characteristics fit well to these requirements. However, the response of RC films and their digitizing processes present a significant spatial inhomogeneity problem. The present work uses a method for two-dimensional (2D) measurement with RC films based on the reduction of the spatial inhomogeneity of both the film and the film digitizing process. By means of registering and averaging several measurements of the same field, the inhomogeneities are mostly canceled. Measurements of output factors (OFs), dose profiles (in-plane and cross-plane), and 2D dose distributions are presented. The field sizes investigated are 0.5 × 0.5 cm2, 0.7 × 0.7 cm2, 1 × 1 cm2, 2 × 2 cm2, 3 × 3 cm2, 6 × 6 cm2, and 10 × 10 cm2 for 6 and 15 MV photon beams. The OFs measured with the RC film are compared with the measurements carried out with a PinPoint ionization chamber (IC) and a Semiflex IC, while the measured transversal dose profiles were compared with Monte Carlo simulations. The results obtained for the OFs measurements show a good agreement with the values obtained from RC films and the PinPoint and Semiflex chambers when the field size is greater or equal than 2 × 2 cm2. These agreements give confidence on the accuracy of the method as well as on the results obtained for smaller fields. Also, good agreement was found between the measured profiles and the Monte Carlo calculated profiles for the field size of 1 × 1 cm2. We expect, therefore, that the presented method can be used to perform accurate measurements of small fields.
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Affiliation(s)
| | - Juan-Antonio Vera-Sanchez
- Servicio de Proteccion Radiologica y Fisica Medica, Hospital Sant Joan de Reus, Reus, Tarragona, Spain
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20
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Suman SK, Dubey KA, Mishra BB, Bhardwaj YK, Mondal RK, Seshadri M, Natarajan V, Varshney L. Synthesis of a flexible poly(chloroprene)/methyl red film dosimeter using an environment-benign shear compounding method. Appl Radiat Isot 2015; 98:60-5. [PMID: 25638574 DOI: 10.1016/j.apradiso.2015.01.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 01/20/2015] [Accepted: 01/20/2015] [Indexed: 11/25/2022]
Abstract
The paper reports synthesis of a new film dosimeter based on a solvent-free route. Methyl red (MR) dye was introduced into poly(chloroprene) (PC) in various concentrations. The films were intensely red with λmax ~515nm. The absorbance decreased linearly with absorbed radiation dose up to 30kGy without a significant change in λmax. Color coordinates of the films were also analyzed. Optical micrographs of the films showed no signs of inhomogeneous distribution of MR in the PC matrix, which was attributed to the polarity of PC. Radiation sensitivity, dose response linearity, effects of irradiation temperature and humidity, as well as the rate of fading, were also investigated.
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Affiliation(s)
- S K Suman
- Radiation Safety Systems Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - K A Dubey
- Radiation Technology Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
| | - B B Mishra
- Food Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Y K Bhardwaj
- Radiation Technology Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - R K Mondal
- Radiation Technology Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Murali Seshadri
- Radiation Safety Systems Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - V Natarajan
- Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - L Varshney
- Radiation Technology Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
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21
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Farah N, Francis Z, Abboud M. Analysis of the EBT3 Gafchromic film irradiated with 6 MV photons and 6 MeV electrons using reflective mode scanners. Phys Med 2014; 30:708-12. [PMID: 24880678 DOI: 10.1016/j.ejmp.2014.04.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/04/2014] [Accepted: 04/25/2014] [Indexed: 10/25/2022] Open
Abstract
We explore in our study the effects of electrons and X-rays irradiations on the newest version of the Gafchromic EBT3 film. Experiments are performed using the Varian "TrueBeam 1.6" medical accelerator delivering 6 MV X-ray photons and 6 MeV electron beams as desired. The main interest is to compare the responses of EBT3 films exposed to two separate beams of electrons and photons, for radiation doses ranging up to 500 cGy. The analysis is done on a flatbed EPSON 10000 XL scanner and cross checked on a HP Scanjet 4850 scanner. Both scanners are used in reflection mode taking into account landscape and portrait scanning positions. After thorough verifications, the reflective scanning method can be used on EBT3 as an economic alternative to the transmission method which was also one of the goals of this study. A comparison is also done between single scan configuration including all samples in a single A4 (HP) or A3 (EPSON) format area and multiple scan procedure where each sample is scanned separately on its own. The images analyses are done using the ImageJ software. Results show significant influence of the scanning configuration but no significant differences between electron and photon irradiations for both single and multiple scan configurations. In conclusion, the film provides a reliable relative dose measurement method for electrons and photons irradiations in the medical field applications.
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Affiliation(s)
- Nicolas Farah
- Physics Department, Faculty of Science, Saint Joseph University, B.P. 11-514 Riad El Solh, Beirut 1107 2050, Lebanon; Department of Radiation-Oncology, Hôtel-Dieu de France Hospital, PO Box HDF 166830, Beirut, Lebanon
| | - Ziad Francis
- Physics Department, Faculty of Science, Saint Joseph University, B.P. 11-514 Riad El Solh, Beirut 1107 2050, Lebanon; The Open University, Faculty of Science, Department of Physical Sciences, Walton Hall, MK7 6AA Milton Keynes, United Kingdom.
| | - Marie Abboud
- Physics Department, Faculty of Science, Saint Joseph University, B.P. 11-514 Riad El Solh, Beirut 1107 2050, Lebanon.
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Varadharajan E, Ramasubramanian V. Commissioning and Acceptance Testing of the existing linear accelerator upgraded to volumetric modulated arc therapy. Rep Pract Oncol Radiother 2014; 18:286-97. [PMID: 24416566 DOI: 10.1016/j.rpor.2013.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 04/17/2013] [Accepted: 07/08/2013] [Indexed: 11/28/2022] Open
Abstract
AIM The RapidArc commissioning and Acceptance Testing program will test and ensure accuracy in DMLC position, precise dose-rate control during gantry rotation and accurate control of gantry speed. BACKGROUND Recently, we have upgraded our linear accelerator capable of performing IMRT which was functional from 2007 with image guided RapidArc facility. The installation of VMAT in the existing linear accelerator is a tedious process which requires many quality assurance procedures before the proper commissioning of the facility and these procedures are discussed in this study. MATERIALS AND METHODS Output of the machine at different dose rates was measured to verify its consistency at different dose rates. Monitor and chamber linearity at different dose rates were checked. DMLC QA comprising of MLC transmission factor measurement and dosimetric leaf gap measurements were performed using 0.13 cm(3) and 0.65 cm(3) Farmer type ionization chamber, dose 1 dosimeter, and IAEA 30 cm × 30 cm × 30 cm water phantom. Picket fence test, garden fence test, tests to check leaf positioning accuracy due to carriage movement, calibration of the leaves, leaf speed stability effects due to the acceleration and deceleration of leaves, accuracy and calibration of leaves in producing complex fields, effects of interleaf friction, etc. were verified using EDR2 therapy films, Vidar scanner, Omnipro accept software, amorphous silicon based electronic portal imaging device and EPIQA software.(1-8.) RESULTS All the DMLC related quality assurance tests were performed and evaluated by film dosimetry, portal dosimetry and EPIQA.(7.) CONCLUSION Results confirmed that the linear accelerator is capable of performing accurate VMAT.
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Affiliation(s)
- Ekambaram Varadharajan
- Department of Radiation Oncology, Billroth Hospitals Ltd., Chennai, India ; School of Advanced Sciences, VIT University, Vellore, India
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23
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Dreindl R, Georg D, Stock M. Radiochromic film dosimetry: considerations on precision and accuracy for EBT2 and EBT3 type films. Z Med Phys 2013; 24:153-63. [PMID: 24055395 DOI: 10.1016/j.zemedi.2013.08.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 08/13/2013] [Accepted: 08/13/2013] [Indexed: 11/19/2022]
Abstract
Gafchromic® EBT2 film is a widely used dosimetric tool for quality assurance in radiation therapy. In 2012 EBT3 was presented as a replacement for EBT2 films. The symmetric structure of EBT3 films to reduce face-up/down dependency as well as the inclusion of a matte film surface to frustrate Newton Ring artifacts present the most prominent improvements of EBT3 films. The aim of this study was to investigate the characteristics of EBT3 films, to benchmark the films against the known EBT2-features and to evaluate the dosimetric behavior over a time period greater than 6 months. All films were irradiated to clinical photon beams (6 MV, 10 MV and 18 MV) on an Elekta Synergy Linac equipped with a Beam Modulator MLC in solid water phantom slabs. Film digitalization was done with a flatbed transparency scanner (Type Epson Expression 1680 Pro). MATLAB® was used for further statistical calculations and image processing. The investigations on post-irradiation darkening, film orientation, film uniformity and energy dependency resulted in negligible differences between EBT2 and EBT3 film. A minimal improvement in face-up/down dependence was found for EBT3. The matte film surface of EBT3 films turned out to be a practical feature as Newton rings could be eliminated completely. Considering long-term behavior (> 6 months) a shift of the calibration curve for EBT2 and EBT3 films due to changes in the dynamic response of the active component was observed. In conclusion, the new EBT3 film yields comparable results to its predecessor EBT2. The general advantages of radiochromic film dosimeters are completed by high film homogeneity, low energy dependence for the observed energy range and a minimized face-up/down dependence. EBT2 dosimetry-protocols can also be used for EBT3 films, but the inclusion of periodical recalibration-interval (e.g. once a quarter) is recommended for protocols of both film generations.
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Affiliation(s)
- Ralf Dreindl
- Department of Radiooncology, Comprehensive Cancer Center, Medical University of Vienna/Vienna General Hospital; EBG MedAustron GmbH, Marie-Curie-Straße 5, 2700 Wiener Neustadt, Austria
| | - Dietmar Georg
- Department of Radiooncology, Comprehensive Cancer Center, Medical University of Vienna/Vienna General Hospital; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna
| | - Markus Stock
- Department of Radiooncology, Comprehensive Cancer Center, Medical University of Vienna/Vienna General Hospital; Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna.
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Wack L, Ngwa W, Tryggestad E, Tsiamas P, Berbeco R, Ng SK, Hesser J, Zygmanski P. High throughput film dosimetry in homogeneous and heterogeneous media for a small animal irradiator. Phys Med 2013; 30:36-46. [PMID: 23510532 DOI: 10.1016/j.ejmp.2013.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 02/04/2013] [Accepted: 02/11/2013] [Indexed: 10/27/2022] Open
Abstract
PURPOSE We have established a high-throughput Gafchromic film dosimetry protocol for narrow kilovoltage beams in homogeneous and heterogeneous media for small-animal radiotherapy applications. The kV beam characterization is based on extensive Gafchromic film dosimetry data acquired in homogeneous and heterogeneous media. An empirical model is used for parameterization of depth and off-axis dependence of measured data. METHODS We have modified previously published methods of film dosimetry to suit the specific tasks of the study. Unlike film protocols used in previous studies, our protocol employs simultaneous multi-channel scanning and analysis of up to nine Gafchromic films per scan. A scanner and background correction were implemented to improve accuracy of the measurements. Measurements were taken in homogeneous and inhomogeneous phantoms at 220 kVp and a field size of 5 × 5 mm(2). The results were compared against Monte Carlo simulations. RESULTS Dose differences caused by variations in background signal were effectively removed by the corrections applied. Measurements in homogeneous phantoms were used to empirically characterize beam data in homogeneous and heterogeneous media. Film measurements in inhomogeneous phantoms and their empirical parameterization differed by about 2%-3%. The model differed from MC by about 1% (water, lung) to 7% (bone). Good agreement was found for measured and modelled off-axis ratios. CONCLUSIONS EBT2 films are a valuable tool for characterization of narrow kV beams, though care must be taken to eliminate disturbances caused by varying background signals. The usefulness of the empirical beam model in interpretation and parameterization of film data was demonstrated.
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Affiliation(s)
- L Wack
- Department of Radiation Oncology, Brigham & Women's Hospital, Boston, MA, USA; Department of Experimental Radiation Oncology, University Medical Center, Mannheim, Germany.
| | - W Ngwa
- Department of Radiation Oncology, Brigham & Women's Hospital, Boston, MA, USA
| | - E Tryggestad
- Department of Radiation Oncology and Molecular Radiation Sciences, John Hopkins University, Baltimore, USA
| | - P Tsiamas
- Department of Radiation Oncology, Brigham & Women's Hospital, Boston, MA, USA
| | - R Berbeco
- Department of Radiation Oncology, Brigham & Women's Hospital, Boston, MA, USA
| | - S K Ng
- Department of Radiation Oncology, Brigham & Women's Hospital, Boston, MA, USA
| | - J Hesser
- Department of Experimental Radiation Oncology, University Medical Center, Mannheim, Germany
| | - P Zygmanski
- Department of Radiation Oncology, Brigham & Women's Hospital, Boston, MA, USA.
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Chełmiński K, Bulski W, Georg D, Bodzak D, Maniakowski Z, Oborska D, Rostkowska J, Kania M. Energy dependence of radiochromic dosimetry films for use in radiotherapy verification. Rep Pract Oncol Radiother 2010; 15:40-6. [PMID: 24376922 DOI: 10.1016/j.rpor.2010.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 02/17/2010] [Accepted: 02/22/2010] [Indexed: 10/19/2022] Open
Abstract
AIM The purpose of the study was to examine the energy dependence of Gafchromic EBT radiochromic dosimetry films, in order to assess their potential use in intensity-modulated radiotherapy (IMRT) verifications. MATERIALS AND METHODS The film samples were irradiated with doses from 0.1 to 12 Gy using photon beams from the energy range 1.25 MeV to 25 MV and the film response was measured using a flat-bed scanner. The samples were scanned and the film responses for different beam energies were compared. RESULTS A high uncertainty in readout of the film response was observed for samples irradiated with doses lower than 1 Gy. The relative difference exceeds 20% for doses lower than 1 Gy while for doses over 1 Gy the measured film response differs by less than 5% for the whole examined energy range. The achieved uncertainty of the experimental procedure does not reveal any energy dependence of Gafchromic EBT film response in the investigated energy range. CONCLUSIONS Gafchromic EBT film does not show any energy dependence in the conditions typical for IMRT but the doses measured for pre-treatment plan verifications should exceed 1 Gy.
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Affiliation(s)
- Krzysztof Chełmiński
- Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland
| | - Wojciech Bulski
- Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland
| | - Dietmar Georg
- Division of Medical Radiation Physics, University of Vienna Medical School, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Dominika Bodzak
- Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland
| | - Zbigniew Maniakowski
- Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, Wybrzeże Armii Krajowej 15, 44-101 Gliwice, Poland
| | - Dominika Oborska
- Department of Medical Physics, Lower Silesian Oncology Centre, pl. Hirszfelda 12, 53-413 Wrocław, Poland
| | - Joanna Rostkowska
- Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland
| | - Małgorzata Kania
- Department of Medical Physics, The Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, ul. Roentgena 5, 02-781 Warsaw, Poland
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