Feasibility of output quality assurance considering gantry angle using “Stealth Chamber”

• Autorzy: Miura Hideharu , Takeichi Fumika , Enosaki Tsubasa , Yamada Kiyoshi , Ozawa Shuichi , Nagata Yasushi

Identyfikatory

DOI

10.2478/pjmpe-2021-0035

• Języki publikacji: EN

Abstrakty

EN

Purpose: This study was conducted to demonstrate the feasibility of X-ray output constancy quality assurance (QA) of a linear accelerator for various gantry angles using the Stealth Chamber. Methods: The X-ray output constancy of a Varian TrueBeam STx was evaluated under various gantry angles and a 10 × 10 cm² field size using a Stealth Chamber. Specifically, 10X and 10X-flattening-filter-free beams with dose rates of 600 and 2400 monitor units (MU)/min, respectively, were used. The Stealth Chamber was attached to the gantry head, and irradiation was performed every 45° for gantry angles of 0-315°. To evaluate the variations in the output constancy with respect to the gantry angle, the acquired values were normalized to the value corresponding to a 0° gantry angle. The obtained results were utilized to determine the correction factors for all gantry angles. To verify the correction factors, additional measurements were performed for five days. Results: The maximum variation in the output constancy measurement relative to the output constancy at a 0° gantry angle was found to be approximately 4.0% for both energy beams at a gantry angle of 180°. Furthermore, the measured values were dependent on the gantry angle. Upon applying the correction factor, the variation in the output constancy with respect to the gantry angle was less than 0.5%. Conclusions: Output constancy QA using the Stealth Chamber for various gantry angles was found to be feasible with the application of a correction factor.

Słowa kluczowe

EN

quality assurance; gantry angle dependence; reference chamber

• Wydawca: Polskie Towarzystwo Fizyki Medycznej ; De Gruyter
• Czasopismo: Polish Journal of Medical Physics and Engineering
• Rocznik: 2021
• Tom: Vol. 27, Iss. 4
• Strony: 299--302
• Opis fizyczny: Bibliogr. 8 poz., rys., tab.

Twórcy

autor

Miura Hideharu

• Hiroshima High-Precision Radiotherapy Cancer Center, Japan

autor

Takeichi Fumika

• Gifu Prefectural General Medical Center, Japan

autor

Enosaki Tsubasa

• Hiroshima High-Precision Radiotherapy Cancer Center, Japan

autor

Yamada Kiyoshi

• Hiroshima High-Precision Radiotherapy Cancer Center, Japan

autor

Ozawa Shuichi

• Hiroshima High-Precision Radiotherapy Cancer Center, Japan

autor

Nagata Yasushi

• Hiroshima High-Precision Radiotherapy Cancer Center, Japan

Bibliografia

• 1. ICRU Report 24. Determination of absorbed dose in a patient irradiated by beams of x- or gamma-rays in radiotherapy procedures. J ICRU. 1976;os13(1). https://doi.org/10.1093/jicru/os13.1.Report24
• 2. Kutcher GJ, Coia L, Gillin M, et al. Comprehensive QA for radiation oncology: Report of the AAPM Radiation Therapy Committee Task Group 40. Med Phys. 1994;21(4):581–618. https://doi.org/10.1118/1.597316
• 3. Klein EE, Hanley J, Bayouth J, et al. Task Group 142 Report: Quality assurance of medical accelerators. Med Phys. 2009;36(9):4197-242. https://doi.org/10.1118/1.3190392
• 4. Loyd MD, Lane RG, Laxton J, et al. Long term variation in beam symmetry as a function of gantry angle for a computer-controlled linear accelerator. Med Phys. 1989;16(4):614-617. https://doi.org/10.1118/1.596363
• 5. Blad B, Jacobsson L, Wendel P. The influence of the magnetron frequency, the servo settings and the gantry angle on the flatness and the dose calibration of a linear accelerator. J Med Eng Technol. 1998;22(4):185-8. https://doi.org/10.3109/03091909809032539
• 6. Huang JC, Reinstein LE. Evaluation of an innovative plastic cube phantom designed to improve the efficiency of accelerator QA. J Appl Clin Med Phys. 2000;1(4):153-7. https://doi.org/10.1120/1.1312382
• 7. Gersh J. Stereotactic beam characterization using the IBA stealth chamber reference detector. IBA Dosimetry Whitepaper 2014.
• 8. Vazquez Quino L, Huerta C, Calvo O, et al. Evaluation of a novel reference chamber “stealth chamber” through Monte Carlo simulations and experimental data. Int J Cancer Ther Oncol. 2015;3:4049. https://doi.org/10.14319/ijcto.32.22

Uwagi

Opracowanie rekordu ze środków MNiSW, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2024).