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Khaledi N, Khan R, Gräfe JL. Historical Progress of Stereotactic Radiation Surgery. J Med Phys 2023; 48:312-327. [PMID: 38223793 PMCID: PMC10783188 DOI: 10.4103/jmp.jmp_62_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/24/2023] [Accepted: 09/27/2023] [Indexed: 01/16/2024] Open
Abstract
Radiosurgery and stereotactic radiotherapy have established themselves as precise and accurate areas of radiation oncology for the treatment of brain and extracranial lesions. Along with the evolution of other methods of radiotherapy, this type of treatment has been associated with significant advances in terms of a variety of modalities and techniques to improve the accuracy and efficacy of treatment. This paper provides a comprehensive overview of the progress in stereotactic radiosurgery (SRS) over several decades, and includes a review of various articles and research papers, commencing with the emergence of stereotactic techniques in radiotherapy. Key clinical aspects of SRS, such as fixation methods, radiobiology considerations, quality assurance practices, and treatment planning strategies, are presented. In addition, the review highlights the technological advancements in treatment modalities, encompassing the transition from cobalt-based systems to linear accelerator-based modalities. By addressing these topics, this study aims to offer insights into the advancements that have shaped the field of SRS, that have ultimately enhanced the accuracy and effectiveness of treatment.
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Affiliation(s)
- Navid Khaledi
- Department of Medical Physics, Cancer Care Manitoba, Winnipeg, MB, Canada
| | - Rao Khan
- Department of Physics, Toronto Metropolitan University, Toronto, ON, Canada
- Department of Physics and Astronomy and Department of Radiation Oncology, Howard University, Washington, District of Columbia, USA
| | - James L. Gräfe
- Department of Physics, Toronto Metropolitan University, Toronto, ON, Canada
- Cancer Care Program, Dr. H. Bliss Murphy Cancer Center. 300 Prince Philip Drive St. John’s, NL, Canada
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2
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Zhao X, Stanley DN, Cardenas CE, Harms J, Popple RA. Do we need patient-specific QA for adaptively generated plans? Retrospective evaluation of delivered online adaptive treatment plans on Varian Ethos. J Appl Clin Med Phys 2022; 24:e13876. [PMID: 36560887 PMCID: PMC9924122 DOI: 10.1002/acm2.13876] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/09/2022] [Accepted: 11/15/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The clinical introduction of dedicated treatment units for online adaptive radiation therapy (OART) has led to widespread adoption of daily adaptive radiotherapy. OART allows for rapid generation of treatment plans using daily patient anatomy, potentially leading to reduction of treatment margins and increased normal tissue sparing. However, the OART workflow does not allow for measurement of patient-specific quality assurance (PSQA) during treatment delivery sessions and instead relies on secondary dose calculations for verification of adapted plans. It remains unknown if independent dose verification is a sufficient surrogate for PSQA measurements. PURPOSE To evaluate the plan quality of previously treated adaptive plans through multiple standard PSQA measurements. METHODS This IRB-approved retrospective study included sixteen patients previously treated with OART at our institution. PSQA measurements were performed for each patient's scheduled and adaptive plans: five adaptive plans were randomly selected to perform ion chamber measurements and two adaptive plans were randomly selected for ArcCHECK measurements. The same ArcCHECK 3D dose distribution was also sent to Mobius3D to evaluate the second-check dosimetry system. RESULTS All (n = 96) ion chamber measurements agreed with the planned dose within 3% with a mean of 1.4% (± 0.7%). All (n = 48) plans passed ArcCHECK measurements using a 95% gamma passing threshold and 3%/2 mm criteria with a mean of 99.1% (± 0.7%). All (n = 48) plans passed Mobius3D second-check performed with 95% gamma passing threshold and 5%/3 mm criteria with a mean of 99.0% (± 0.2%). CONCLUSION Plan measurement for PSQA may not be necessary for every online-adaptive treatment verification. We recommend the establishment of a periodic PSQA check to better understand trends in passing rates for delivered adaptive treatments.
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Affiliation(s)
- Xiaodong Zhao
- Department of Radiation OncologyWashington University in St. LouisSt. LouisMissouriUSA
| | - Dennis N. Stanley
- Department of Radiation OncologyUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Carlos E. Cardenas
- Department of Radiation OncologyUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Joseph Harms
- Department of Radiation OncologyUniversity of Alabama at BirminghamBirminghamAlabamaUSA
| | - Richard A. Popple
- Department of Radiation OncologyUniversity of Alabama at BirminghamBirminghamAlabamaUSA
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3
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Han B, Capaldi D, Kovalchuk N, Simiele E, White J, Zaks D, Xing L, Surucu M. Beam commissioning of the first clinical biology-guided radiotherapy system. J Appl Clin Med Phys 2022; 23:e13607. [PMID: 35482018 PMCID: PMC9194984 DOI: 10.1002/acm2.13607] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/15/2022] [Accepted: 03/22/2022] [Indexed: 11/28/2022] Open
Abstract
This study reports the beam commissioning results for the first clinical RefleXion Linac. Methods: The X1 produces a 6 MV photon beam and the maximum clinical field size is 40 × 2 cm2 at source‐to‐axis distance of 85 cm. Treatment fields are collimated by a binary multileaf collimator (MLC) system with 64 leaves with width of 0.625 cm and y‐jaw pairs to provide either a 1 or 2 cm opening. The mechanical alignment of the radiation source, the y‐jaw, and MLC were checked with film and ion chambers. The beam parameters were characterized using a diode detector in a compact water tank. In‐air lateral profiles and in‐water percentage depth dose (PDD) were measured for beam modeling of the treatment planning system (TPS). The lateral profiles, PDDs, and output factors were acquired for field sizes from 1.25 × 1 to 40 × 2 cm2 field to verify the beam modeling. The rotational output variation and synchronicity were tested to check the gantry angle, couch motion, and gantry rotation. Results: The source misalignments were 0.049 mm in y‐direction, 0.66% out‐of‐focus in x‐direction. The divergence of the beam axis was 0.36 mm with a y‐jaw twist of 0.03°. Clinical off‐axis treatment fields shared a common center in y‐direction were within 0.03 mm. The MLC misalignment and twist were 0.57 mm and 0.15°. For all measured fields ranging from the size from 1.25 × 1 to 40 × 2 cm2, the mean difference between measured and TPS modeled PDD at 10 cm depth was −0.3%. The mean transverse profile difference in the field core was −0.3% ± 1.1%. The full‐width half maximum (FWHM) modeling was within 0.5 mm. The measured output factors agreed with TPS within 0.8%. Conclusions: This study summarizes our specific experience commissioning the first novel RefleXion linac, which may assist future users of this technology when implementing it into their own clinics.
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Affiliation(s)
- Bin Han
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Dante Capaldi
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Nataliya Kovalchuk
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Eric Simiele
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - John White
- RefleXion Medical, Hayward, California, USA
| | | | - Lei Xing
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
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4
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Shi M, Chuang CF, Kovalchuk N, Bush K, Zaks D, Xing L, Surucu M, Han B. Small-field measurement and Monte Carlo model validation of a novel image-guided radiotherapy system. Med Phys 2021; 48:7450-7460. [PMID: 34628666 DOI: 10.1002/mp.15273] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 09/09/2021] [Accepted: 09/25/2021] [Indexed: 02/02/2023] Open
Abstract
PURPOSE The RefleXion™ X1 is a novel radiotherapy system that is designed for image-guided radiotherapy, and eventually, biology-guided radiotherapy (BgRT). BgRT is a treatment paradigm that tracks tumor motion using real-time positron emission signals. This study reports the small-field measurement results and the validation of a Monte Carlo (MC) model of the first clinical RefleXion unit. METHODS The RefleXion linear accelerator (linac) produces a 6 MV flattening filter free (FFF) photon beam and consists of a binary multileaf collimator (MLC) system with 64 leaves and two pairs of y-jaws. The maximum clinical field size achievable is 400 × 20 mm2 . The y-jaws provide either a 10 or 20 mm opening at source-to-axis distance (SAD) of 850 mm. The width of each MLC leaf at SAD is 6.25 mm. Percentage depth doses (PDDs) and relative beam profiles were acquired using an Edge diode detector in a water tank for field sizes from 12.5 × 10 to 100 × 20 mm2 . Beam profiles were also measured using films. Output factors of fields ranging from 6.25 × 10 to 100 × 20 mm2 were measured using W2 scintillator detector, Edge detector, and films. Output correction factors k of the Edge detector for RefleXion were calculated. An MC model of the linac including pre-MLC beam sources and detailed structures of MLC and lower y-jaws was validated against the measurements. Simulation codes BEAMnrc and GATE were utilized. RESULTS The diode measured PDD at 10 cm depth (PDD10) increases from 53.6% to 56.9% as the field opens from 12.5 × 10 to 100 × 20 mm2 . The W2-measured output factor increases from 0.706 to 1 as the field opens from 6.25 × 10 to 100 × 20 mm2 (reference field size). The output factors acquired by diode and film differ from the W2 results by 1.65% (std = 1.49%) and 2.09% (std = 1.41%) on average, respectively. The profile penumbra and full-width half-maximum (FWHM) measured by diode agree well with the film results with a deviation of 0.60 mm and 0.73% on average, respectively. The averaged beam profile consistency calculated between the diode- and film-measured profiles among different depths is within 1.72%. By taking the W2 measurements as the ground truth, the output correction factors k for Edge detector ranging from 0.958 to 1 were reported. For the MC model validation, the simulated PDD10 agreed within 0.6% to the diode measurement. The MC-simulated output factor differed from the W2 results by 2.3% on average (std = 3.7%), while the MC simulated beam penumbra differed from the diode results by 0.67 mm on average (std = 0.42 mm). The MC FWHM agreed with the diode results to within 1.40% on average. The averaged beam profile consistency calculated between the diode and MC profiles among different depths is less than 1.29%. CONCLUSIONS This study represents the first small-field dosimetry of a clinical RefleXion system. A complete and accurate MC model of the RefleXion linac has been validated.
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Affiliation(s)
- Mengying Shi
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Cynthia F Chuang
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Nataliya Kovalchuk
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Karl Bush
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | | | - Lei Xing
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
| | - Bin Han
- Department of Radiation Oncology, Stanford University, Stanford, California, USA
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5
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Huang Z, Qiao J, Yang C, Liu M, Wang J, Han X, Hu W. Quality Assurance for Small-Field VMAT SRS and Conventional-Field IMRT Using the Exradin W1 Scintillator. Technol Cancer Res Treat 2021; 20:15330338211036542. [PMID: 34328800 PMCID: PMC8327019 DOI: 10.1177/15330338211036542] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Plastic scintillator detector (PSD) Exradin W1 has shown promising performance in small field dosimetry due to its water equivalence and small sensitive volume. However, few studies reported its capability in measuring fields of conventional sizes. Therefore, the purpose of this study is to assess the performance of W1 in measuring point dose of both conventional IMRT plans and VMAT SRS plans. METHODS Forty-seven clinical plans (including 29 IMRT plans and 18 VMAT SRS plans with PTV volume less than 8 cm3) from our hospital were included in this study. W1 and Farmer-Type ionization chamber Exradin A19 were used in measuring IMRT plans, and W1 and microchamber Exradin A16 were used in measuring SRS plans. The agreement between the results of different types of detectors and TPS was evaluated. RESULTS For IMRT plans, the average differences between measurements and TPS in high-dose regions were 0.27% ± 1.66% and 0.90% ± 1.78% (P = 0.056), and were -0.76% ± 1.47% and 0.37% ± 1.34% in low-dose regions (P = 0.000), for W1 and A19, respectively. For VMAT SRS plans, the average differences between measurements and TPS were -0.19% ± 0.96% and -0.59% ± 1.49% for W1 and A16 with no statistical difference (P = 0.231). CONCLUSION W1 showed comparable performance with application-dedicated detectors in point dose measurements for both conventional IMRT and VMAT SRS techniques. It is a potential one-stop solution for general radiotherapy platforms that deliver both IMRT and SRS plans.
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Affiliation(s)
- Zike Huang
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jian Qiao
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Cui Yang
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ming Liu
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jiazhou Wang
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xu Han
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Weigang Hu
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
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Öllers MC, Swinnen ACC, Verhaegen F. Acuros
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dose verification of ultrasmall lung lesions with EBT‐XD film in a homogeneous and heterogeneous anthropomorphic phantom setup. Med Phys 2020; 47:5829-5837. [DOI: 10.1002/mp.14485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/27/2020] [Accepted: 09/07/2020] [Indexed: 02/01/2023] Open
Affiliation(s)
- Michel C. Öllers
- Department of Radiation Oncology (Maastro) GROW School for Oncology Maastricht University Medical Centre+ Maastricht The Netherlands
| | - Ans C. C. Swinnen
- Department of Radiation Oncology (Maastro) GROW School for Oncology Maastricht University Medical Centre+ Maastricht The Netherlands
| | - Frank Verhaegen
- Department of Radiation Oncology (Maastro) GROW School for Oncology Maastricht University Medical Centre+ Maastricht The Netherlands
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7
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Rose MS, Tirpak L, Van Casteren K, Zack J, Simon T, Schoenfeld A, Simon W. Multi‐institution validation of a new high spatial resolution diode array for SRS and SBRT plan pretreatment quality assurance. Med Phys 2020; 47:3153-3164. [DOI: 10.1002/mp.14153] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 02/20/2020] [Accepted: 03/12/2020] [Indexed: 12/31/2022] Open
Affiliation(s)
- Mark S. Rose
- Sun Nuclear Corporation 3275 Suntree Blvd Melbourne Florida 32940 USA
| | - Lena Tirpak
- Sun Nuclear Corporation 3275 Suntree Blvd Melbourne Florida 32940 USA
| | | | - Jeff Zack
- Sun Nuclear Corporation 3275 Suntree Blvd Melbourne Florida 32940 USA
| | - Tom Simon
- Sun Nuclear Corporation 3275 Suntree Blvd Melbourne Florida 32940 USA
| | | | - William Simon
- Sun Nuclear Corporation 3275 Suntree Blvd Melbourne Florida 32940 USA
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8
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Snyder JD, Sullivan RJ, Wu X, Covington EL, Popple RA. Use of a plastic scintillator detector for patient-specific quality assurance of VMAT SRS. J Appl Clin Med Phys 2020; 20:143-148. [PMID: 31538717 PMCID: PMC6753731 DOI: 10.1002/acm2.12705] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/13/2019] [Accepted: 07/25/2019] [Indexed: 11/30/2022] Open
Abstract
Purpose To evaluate a scintillator detector for patient‐specific quality assurance of VMAT radiosurgery plans. Methods The detector was comprised of a 1 mm diameter, 1 mm high scintillator coupled to an acrylic optical fiber. Sixty VMAT SRS plans for treatment of single targets having sizes ranging from 3 mm to 30.2 mm equivalent diameter (median 16.3 mm) were selected. The plans were delivered to a 20 cm × 20 cm x 15 cm water equivalent plastic phantom having either the scintillator detector or radiochromic film at the center. Calibration films were obtained for each measurement session. The films were scanned and converted to dose using a 3‐channel technique. Results The mean difference between scintillator and film was ‒0.45% (95% confidence interval ‒0.1% to 0.8%). For target equivalent diameter smaller than the median, the mean difference was 1.1% (95% confidence interval 0.5% to 1.7%). For targets larger than the median, the mean difference was ‒0.2% (95% confidence interval ‒0.7% to 0.1%). Conclusions The scintillator detector response is independent of target size for targets as small as 3 mm and is well‐suited for patient‐specific quality assurance of VMAT SRS plans. Further work is needed to evaluate the accuracy for VMAT plans that treat multiple targets using a single isocenter.
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Affiliation(s)
- Jesse D Snyder
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rodney J Sullivan
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Xingen Wu
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Elizabeth L Covington
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Richard A Popple
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
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Jeong S, Chung K, Ahn SH, Lee B, Seo J, Yoon M. Feasibility study of a plastic scintillating plate-based treatment beam fluence monitoring system for use in pencil beam scanning proton therapy. Med Phys 2019; 47:703-712. [PMID: 31732965 DOI: 10.1002/mp.13922] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/14/2019] [Accepted: 11/06/2019] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The purpose of this study was to describe a plastic scintillating plate-based gantry-attachable dosimetry system for pencil beam scanning proton therapy to monitor entrance proton beam fluence, and to evaluate the dosimetric characteristics of this system and its feasibility for clinical use. METHODS The dosimetry system, consisting of a plastic scintillating plate and a CMOS camera, was attached to a dedicated scanning nozzle and scintillation during proton beam irradiation was recorded. Dose distribution was calculated from the accumulated recorded frames. The dosimetric characteristics (energy dependency, dose linearity, dose rate dependency, and reproducibility) of the gantry-attachable dosimetry system for use with therapeutic proton beams were measured, and the feasibility of this system during clinical use was evaluated by determining selected quality assurance items at our institution. RESULTS The scintillating plate shortened the range of the proton beam by the water-equivalent thickness of the plate and broadened the spatial profile of the single proton spot by 11% at 70 MeV. The developed system functioned independently of the beam energy (<1.3%) and showed dose linearity, and also functioned independently of the dose rate. The feasibility of the system for clinical use was evaluated by comparing the measured quality assurance dose distribution to that of the treatment planning system. The gamma passing rate with a criterion of 3%/3 mm was 97.58%. CONCLUSIONS This study evaluated the dosimetric characteristics of a plastic scintillating plate-based dosimetry system for use with scanning proton beams. The ability to account for the interference of the dosimetry system on the therapeutic beam enabled offline monitoring of the entrance beam fluence of the pencil beam scanning proton therapy independent of the treatment system with high resolution and in a cost-effective manner.
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Affiliation(s)
- Seonghoon Jeong
- Department of Bio-Convergence Engineering, Korea University, Seoul, Republic of Korea
| | - Kwangzoo Chung
- Department of Radiation Oncology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea
| | - Sung Hwan Ahn
- Department of Radiation Oncology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea
| | - Boram Lee
- Department of Radiation Oncology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea
| | - Jaehyeon Seo
- Department of Bio-Convergence Engineering, Korea University, Seoul, Republic of Korea
| | - Myonggeun Yoon
- Department of Bio-Convergence Engineering, Korea University, Seoul, Republic of Korea
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Evaluating small field dosimetry with the Acuros XB (AXB) and analytical anisotropic algorithm (AAA) dose calculation algorithms in the eclipse treatment planning system. JOURNAL OF RADIOTHERAPY IN PRACTICE 2019. [DOI: 10.1017/s1460396919000104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractBackground:An increasing number of external beam treatment modalities including intensity modulated radiation therapy, volumetric modulated arc therapy (VMAT) and stereotactic radiosurgery uses very small fields for treatment planning and delivery. However, there are major challenges in small photon field dosimetry, due to the partial occlusion of the direct photon beam source’s view from the measurement point, lack of lateral charged particle equilibrium, steep dose-rate gradient and volume averaging effect of the detector response and variation of the energy fluence in the lateral direction of the beam. Therefore, experimental measurements of dosimetric parameters such as percent depth doses (PDDs), beam profiles and relative output factors (ROFs) for small fields continue to be a challenge.Materials and Methods:In this study, we used a homogeneous water phantom and the heterogeneous anthropomorphic stereotactic end-to-end verification (STEEV) head phantom for all dose measurements and calculations. PDDs, lateral dose profiles and ROFs were calculated in the Eclipse Treatment Planning System version 13·6 using the Acuros XB (AXB) and the analytical anisotropic algorithms (AAAs) in a homogenous water phantom. Monte Carlo (MC) simulations and measurements using the Exradin W1 Scintillator were also accomplished for four photon energies: 6 MV, 6FFF, 10 MV and 10FFF. Two VMAT treatment plans were generated for two different targets: one located in the brain and the other in the neck (close to the trachea) in the head phantom (CIRS, Norfolk, VA, USA). A Varian Truebeam linear accelerator (Varian, Palo Alto, CA, USA) was used for all treatment deliveries. Calculated results with AXB and AAA were compared with MC simulations and measurements.Results:The average difference of PDDs between W1 Exradin Scintillator measurements and MC simulations, AAA and AXB algorithm calculations were 1·2, 2·4 and 3·2%, respectively, for all field sizes and energies. AXB and AAA showed differences in ROF of about 0·3 and 2·9%, respectively, compared with W1 Exradin Scintillator measured values. For the target located in the brain in the head phantom, the average dose difference between W1 Exradin Scintillator and the MC simulations, AAA and AXB were 0·2, 3·2 and 2·7%, respectively, for all field sizes. Similarly, for the target located in the neck, the respective dose differences were 3·8, 5·7 and 3·5%.Conclusion:In this study, we compared dosimetric parameters such as PDD, beam profile and ROFs in water phantom and isocenter point dose measurements in an anthropomorphic head phantom representing a patient. We observed that measurements using the W1 Exradin scintillator agreed well with MC simulations and can be used efficiently for dosimetric parameters such as PDDs and dose profiles and patient-specific quality assurance measurements for small fields. In both homogenous and heterogeneous media, the AXB algorithm dose prediction agrees well with MC and measurements and was found to be superior to the AAA algorithm.
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11
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Fukui Y, Hamada Y, Noma K, Harada N. [Characterization of Small Volume Plastic Scintillation Detector]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2019; 75:652-658. [PMID: 31327776 DOI: 10.6009/jjrt.2019_jsrt_75.7.652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Some radiation detectors are used for quality assurance and measured to radiation dose for high precision external beam radiotherapy. Recently, plastic scintillation detectors for MeV X-ray measurement are commercially released. The purpose of this study was to evaluate the performance of a commercial plastic scintillation detector with respect to the dose linearity, dose rate dependence, and the output coefficient compared the ionization chamber and the semiconductor detector using each different X-ray energy with or without flattening filter. The result that the dose linearity of each detector showed a linear response in any detectors. Dose rate dependence of plastic scintillation detector was increased when setting dose rate was changed, especially setting to low dose rate. The output coefficient of plastic scintillation detector was equivalent as that of the semiconductor detector even in smallest irradiation field. In conclusion, it was suggested that the plastic scintillation detector is a suitable detector in dose verification measurements for high precision external beam radiotherapy, although we must be with care to low dose rate measurements.
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Affiliation(s)
- Yusuke Fukui
- Radiology Service, Shiga University of Medical Science Hospital
| | - Yuto Hamada
- Radiology Service, Shiga University of Medical Science Hospital (Current address: Canon Medical Systems Corporation)
| | - Kazuo Noma
- Radiology Service, Shiga University of Medical Science Hospital
| | - Naoki Harada
- Radiology Service, Shiga University of Medical Science Hospital
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Hillman Y, Kim J, Chetty I, Wen N. Refinement of MLC modeling improves commercial QA dosimetry system for SRS and SBRT patient-specific QA. Med Phys 2018; 45:1351-1359. [DOI: 10.1002/mp.12808] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 01/15/2018] [Accepted: 01/23/2018] [Indexed: 01/17/2023] Open
Affiliation(s)
- Yair Hillman
- Department of Radiation Oncology; Karmanos Cancer Institute at McLaren Macomb; Mt. Clemens MI USA
| | - Josh Kim
- Department of Radiation Oncology; Henry Ford Hospital; Detroit MI USA
| | - Indrin Chetty
- Department of Radiation Oncology; Henry Ford Hospital; Detroit MI USA
| | - Ning Wen
- Department of Radiation Oncology; Henry Ford Hospital; Detroit MI USA
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