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Sadrollahi A, Nuesken F, Licht N, Rübe C, Dzierma Y. Monte-Carlo simulation of the Siemens Artiste linear accelerator flat 6 MV and flattening-filter-free 7 MV beam line. PLoS One 2019; 14:e0210069. [PMID: 30620742 PMCID: PMC6324801 DOI: 10.1371/journal.pone.0210069] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 12/17/2018] [Indexed: 11/18/2022] Open
Abstract
The aim of our work is to provide the up-to-now missing information on the Siemens Artiste FFF 7 MV beam line using a Monte-Carlo model fit to the realistic dosimetric measurements at the linear accelerator in clinical use at our department. The main Siemens Artiste 6MV and FFF 7MV beams were simulated using the Geant4 toolkit. The simulations were compared with the measurements with an ionization chamber in a water phantom to verify the validation of simulation and tuning the primary electron parameters. Hereafter, other parameters such as surface dose, spectrum, electron contamination, symmetry, flatness/unflatness, slope, and characteristic off-axis changes were discussed for both Flat and FFF mode. The mean electron energy for the FFF beam was 8.8 MeV and 7.5 MeV for Flat 6 MV, the spread energy and spot size of the selected Gaussian distribution source were 0.4 MeV and 1mm, respectively. The dose rate of the FFF beam was 2.8 (2.96) times higher than for the flattened beam for a field size of 10×10 (20×20) cm2. The electron contamination has significant contribution to the surface dose especially for the flattened beam. The penumbra, surface dose and the mean energy of photons decrease by removing the flattening filter. Finally, the results show that off-axis changes have no strong effect on the mean energy of FFF beams, while this effect was more considerable for the flattened beam.
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Affiliation(s)
- Alemeh Sadrollahi
- Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, Homburg, Saarland, Germany
- * E-mail:
| | - Frank Nuesken
- Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, Homburg, Saarland, Germany
| | - Norbert Licht
- Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, Homburg, Saarland, Germany
| | - Christian Rübe
- Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, Homburg, Saarland, Germany
| | - Yvonne Dzierma
- Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, Homburg, Saarland, Germany
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Duncan M, Newall MK, Caillet V, Booth JT, Keall PJ, Lerch M, Perevertaylo V, Rosenfeld AB, Petasecca M. Real-time high spatial resolution dose verification in stereotactic motion adaptive arc radiotherapy. J Appl Clin Med Phys 2018; 19:173-184. [PMID: 29873185 PMCID: PMC6036363 DOI: 10.1002/acm2.12364] [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: 11/29/2017] [Revised: 03/08/2018] [Accepted: 04/18/2018] [Indexed: 12/25/2022] Open
Abstract
Purpose Radiation treatments delivered with real‐time multileaf collimator (MLC) tracking currently lack fast pretreatment or real‐time quality assurance. The purpose of this study is to test a 2D silicon detector, MagicPlate‐512 (MP512), in a complex clinical environment involving real‐time reconfiguration of the MLC leaves during target tracking. Methods MP512 was placed in the center of a solid water phantom and mounted on a motion platform used to simulate three different patient motions. Electromagnetic target tracking was implemented using the Calypso system (Varian Medical Systems, Palo Alto, CA, USA) and an MLC tracking software. A two‐arc VMAT plan was delivered and 2D dose distributions were reconstructed by MP512, EBT3 film, and the Eclipse treatment planning system (TPS). Dose maps were compared using gamma analysis with 2%/2 mm and 3%/3 mm acceptance criteria. Dose profiles were generated in sup‐inf and lateral directions to show the agreement of MP512 to EBT3 and to highlight the efficacy of the MLC tracking system in mitigating the effect of the simulated patient motion. Results Using a 3%/3 mm acceptance criterion for 2D gamma analysis, MP512 to EBT3 film agreement was 99% and MP512 to TPS agreement was 100%. For a 2%/2 mm criterion, the agreement was 95% and 98%, respectively. Full width at half maximum and 80%/20% penumbral width of the MP512 and EBT3 dose profiles agreed within 1 mm and 0.5 mm, respectively. Patient motion increased the measured dose profile penumbral width by nearly 2 mm (with respect to the no‐motion case); however, the MLC tracking strategy was able to mitigate 80% of this effect. Conclusions MP512 is capable of high spatial resolution 2D dose reconstruction during adaptive MLC tracking, including arc deliveries. It shows potential as an effective tool for 2D small field dosimetry and pretreatment quality assurance for MLC tracking modalities. These results provide confidence that detector‐based pretreatment dosimetry is clinically feasible despite fast real‐time MLC reconfigurations.
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Affiliation(s)
- Mitchell Duncan
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Matthew K Newall
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Vincent Caillet
- Northern Sydney Cancer Centre, Royal North Shore Hospital, St. Leonards, NSW, Australia
| | - Jeremy T Booth
- Northern Sydney Cancer Centre, Royal North Shore Hospital, St. Leonards, NSW, Australia.,Institute of Medical Physics, School of Physics, University of Sydney, NSW, Australia
| | - Paul J Keall
- Radiation Physics Laboratory, School of Medicine, University of Sydney, NSW, Australia
| | - Michael Lerch
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | | | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Marco Petasecca
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
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Comparison of Flattening Filter (FF) and Flattening-Filter-Free (FFF) 6 MV photon beam characteristics for small field dosimetry using EGSnrc Monte Carlo code. Radiat Phys Chem Oxf Engl 1993 2017. [DOI: 10.1016/j.radphyschem.2017.02.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Oskan F, Dzierma Y, Wagenpfeil S, Rübe C, Fleckenstein J. Retrospective analysis of stereotactic ablative radiotherapy (SABR) for metastatic lung lesions (MLLs) in comparison with a contemporaneous cohort of primary lung lesions (PLLs). J Thorac Dis 2017; 9:742-756. [PMID: 28449482 DOI: 10.21037/jtd.2017.03.07] [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] [Indexed: 12/31/2022]
Abstract
BACKGROUND The net benefit from local ablative therapy for pulmonary oligometastases remains unknown. The outcomes of stereotactic ablative radiotherapy (SABR) for metastatic lung lesions (MLLs) were analyzed retrospectively and compared with those of SABR for primary lung lesions (PLLs). METHODS Medical records of patients treated with lung SABR between 2011 and 2014 were retrospectively reviewed. Basic patient, lesion and treatment characteristics were compared using the Pearson chi-square test for categorical and Mann-Whitney U test for continuous variables. To estimate the rates of local control (LC), progression-free survival (PFS), survival after the first progression post-SABR (SAPF) and overall survival (OS), the Kaplan-Meier method was used, and the differences between groups were assessed by means of the log rank test. The uni- and multivariate Cox proportional hazards regression model was used to identify predictive factors for these endpoints. RESULTS Twenty-nine MLLs in 18 consecutive patients and 51 PLLs in 42 patients were treated stereotactically and included in the study. Median follow-up was 14 months (range, 4-40 months). Although patients with MLLs had a significantly better cardiopulmonary function (P=0.0001), more conservative dose-fractionation schedules were prescribed (P=0.0001), but this did not result in a significant difference in LC (P=0.98), PFS (P=0.06) and OS (P=0.14). Multivariate analysis revealed that the dose per fraction (≥ or <12 Gy) was an independent predictor for LC (P=0.02) and PFS (P=0.01) for the whole population, and for PFS (P=0.02) in the PLLs group. Late toxicities ≥ G2 occurred in six patients with PLLs, compared with none in the metastatic group. CONCLUSIONS SABR for MLLs was as successful as for PLLs with respect to LC and OS with lower long-term toxicity in patients with MLLs. Dose per fraction ≥12 Gy turned out to be an independent, favorable prognostic factor.
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Affiliation(s)
- Feras Oskan
- Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, 66421 Homburg, Saarland, Germany.,Department of Radiation Oncology, Alb-Fils Kliniken GmbH, Eichertstr. 3, 73035 Goeppingen, Germany
| | - Yvonne Dzierma
- Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, 66421 Homburg, Saarland, Germany
| | - Stefan Wagenpfeil
- Institute of Medical Biometry, Epidemiology and Medical Informatics, Saarland University, Campus Homburg, 66421 Homburg, Saarland, Germany
| | - Christian Rübe
- Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, 66421 Homburg, Saarland, Germany
| | - Jochen Fleckenstein
- Department of Radiotherapy and Radiation Oncology, Saarland University Medical Center, 66421 Homburg, Saarland, Germany
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Baba F, Tanaka S, Nonogaki Y, Hasegawa S, Nishihashi M, Ayakawa S, Yamada M, Shibamoto Y. Effects of audio coaching and visual feedback on the stability of respiration during radiotherapy. Jpn J Radiol 2016; 34:572-8. [DOI: 10.1007/s11604-016-0560-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 05/30/2016] [Indexed: 01/25/2023]
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Ma C, Zhang W, Lu J, Wu L, Wu F, Huang B, Lin Y, Li D. Dosimetric Comparison and Evaluation of Three Radiotherapy Techniques for Use after Modified Radical Mastectomy for Locally Advanced Left-sided Breast Cancer. Sci Rep 2015; 5:12274. [PMID: 26194593 PMCID: PMC4508617 DOI: 10.1038/srep12274] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 06/23/2015] [Indexed: 02/05/2023] Open
Abstract
This study aimed to compare the post-modified radical mastectomy radiotherapy (PMRMRT) for left-sided breast cancer utilizing 3-dimensional conformal radiotherapy with field-in-field technique (3DCRT-FinF), 5-field intensity-modulated radiation therapy (5F-IMRT) and 2- partial arc volumetric modulated arc therapy (2P-VMAT). We created the 3 different PMRMRT plans for each of the ten consecutive patients. We performed Kruskal-Wallis analysis of variance (ANOVA) followed by the Dunn's-type multiple comparisons to establish a hierarchy in terms of plan quality and dosimetric benefits. P < 0.05 was considered statistically significant. Both 5F-IMRT and 2P-VMAT plans exhibited similar PTV coverage (V95%), hotspot areas (V110%) and conformity (all p > 0.05), and significantly higher PTV coverage compared with 3DCRT-FinF (both p < 0.001). In addition, 5F-IMRT plans provided significantly less heart and left lung radiation exposure than 2P-VMAT (all p < 0.05). The 3DCRT-FinF plans with accurately estimated CTV displacement exhibited enhanced target coverage but worse organs at risk (OARs) sparing compared with those plans with underestimated displacements. Our results indicate that 5F-IMRT has dosimetrical advantages compared with the other two techniques in PMRMRT for left-sided breast cancer given its optimal balance between PTV coverage and OAR sparing (especially heart sparing). Individually quantifying and minimizing CTV displacement can significantly improve dosage distribution.
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Affiliation(s)
- Changchun Ma
- Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, 515031, Guangdong Province, China
| | - Wuzhe Zhang
- Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, 515031, Guangdong Province, China
| | - Jiayang Lu
- Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, 515031, Guangdong Province, China
| | - Lili Wu
- Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, 515031, Guangdong Province, China
| | - Fangcai Wu
- Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, 515031, Guangdong Province, China
| | - Baotian Huang
- Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, 515031, Guangdong Province, China
| | - Yan Lin
- Radiology Department, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, Guangdong Province, China
| | - Dongsheng Li
- Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, 515031, Guangdong Province, China
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Respiratory gating during stereotactic body radiotherapy for lung cancer reduces tumor position variability. PLoS One 2014; 9:e112824. [PMID: 25379729 PMCID: PMC4224502 DOI: 10.1371/journal.pone.0112824] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 10/16/2014] [Indexed: 11/19/2022] Open
Abstract
PURPOSE We evaluated the effects of respiratory gating on treatment accuracy in lung cancer patients undergoing lung stereotactic body radiotherapy by using electronic portal imaging device (EPID) images. MATERIALS AND METHODS Our study population consisted of 30 lung cancer patients treated with stereotactic body radiotherapy (48 Gy/4 fractions/4 to 9 days). Of these, 14 were treated with- (group A) and 16 without gating (group B); typically the patients whose tumors showed three-dimensional respiratory motion ≧5 mm were selected for gating. Tumor respiratory motion was estimated using four-dimensional computed tomography images acquired during treatment simulation. Tumor position variability during all treatment sessions was assessed by measuring the standard deviation (SD) and range of tumor displacement on EPID images. The two groups were compared for tumor respiratory motion and position variability using the Mann-Whitney U test. RESULTS The median three-dimensional tumor motion during simulation was greater in group A than group B (9 mm, range 3-30 mm vs. 2 mm, range 0-4 mm; p<0.001). In groups A and B the median SD of the tumor position was 1.1 mm and 0.9 mm in the craniocaudal- (p = 0.24) and 0.7 mm and 0.6 mm in the mediolateral direction (p = 0.89), respectively. The median range of the tumor position was 4.0 mm and 3.0 mm in the craniocaudal- (p = 0.21) and 2.0 mm and 1.5 mm in the mediolateral direction (p = 0.20), respectively. CONCLUSIONS Although patients treated with respiratory gating exhibited greater respiratory tumor motion during treatment simulation, tumor position variability in the EPID images was low and comparable to patients treated without gating. This demonstrates the benefit of respiratory gating.
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