Oonsiri Sornjarod, Kingkaew Sakda, Vimolnoch Mananchaya, Chatchumnan Nichakan, Oonsiri Puntiwa
Department of Radiology, Division of Radiation Oncology, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand.
J Med Phys. 2023 Jul-Sep;48(3):238-242. doi: 10.4103/jmp.jmp_71_23. Epub 2023 Sep 18.
The purpose of the study was to investigate the dosimetric characteristics of radiophotoluminescent glass dosimeters (RGDs) for pencil beam scanning proton therapy. The RGD's end-to-end testing of intensity-modulated proton therapy (IMPT) plans was also evaluated.
The dosimetric characteristics of the GD-302M type glass dosimeter were studied in terms of uniformity, short-term and long-term reproducibility, stability of the magazine position readout, dose linearity in the range from 0.2 to 20 Gy, energy response in 70-220 MeV, and fading effect. The reference conditions of the spot scanning beam from the Varian ProBeam Compact system were operation at 160 MeV, a 2 cm water-equivalent depth in a solid water phantom, a 10 cm × 10 cm field size at the isocenter, and 2 Gy dose delivery. End-to-end testing of IMPT plans for the head, abdomen, and pelvis was verified using the Alderson Rando phantom. The overall uncertainty analysis was confirmed in this study.
The relative response of RGDs for the uniformity test was within 0.95-1.05. The percentages of the coefficients of variation for short-term and long-term reproducibility were 1.16% and 1.50%, respectively. The dose ACE glass dosimetry reader FGD-1000 showed a stable magazine position readout. The dose was found to be linear with = 0.9988. The energy response relative to 160 MeV was approximately within 4.0%. The fading effect was within 2.4%. For the end-to-end test, the difference between the treatment plan and RGD measurement was within 1.0%. The overall uncertainty of the RGD measurement for the proton beam was 4.6%, which covered all energy ranges in this study.
The experimental study indicates that the RGDs have the potential to be used in the dosimetry of therapeutic proton beams, including end-to-end dosimetry.
本研究旨在调查用于笔形束扫描质子治疗的放射光致发光玻璃剂量计（RGD）的剂量学特性。还评估了RGD对调强质子治疗（IMPT）计划的端到端测试。
研究了GD - 302M型玻璃剂量计的剂量学特性，包括均匀性、短期和长期重复性、储片盒位置读数的稳定性、0.2至20 Gy范围内的剂量线性、70 - 220 MeV的能量响应以及衰退效应。Varian ProBeam Compact系统的点扫描束的参考条件为在160 MeV下运行，在固体水模体中2 cm水等效深度处，等中心处10 cm×10 cm的射野尺寸，以及2 Gy的剂量输送。使用Alderson Rando模体对头部、腹部和骨盆的IMPT计划进行端到端测试。本研究证实了总体不确定性分析。
RGD在均匀性测试中的相对响应在0.95 - 1.05范围内。短期和长期重复性的变异系数百分比分别为1.16%和1.50%。剂量ACE玻璃剂量学读数器FGD - 1000显示储片盒位置读数稳定。发现剂量呈线性，R² = 0.9988。相对于160 MeV的能量响应约在4.0%以内。衰退效应在2.4%以内。对于端到端测试，治疗计划与RGD测量之间的差异在1.0%以内。质子束RGD测量的总体不确定性为4.6%，涵盖了本研究中的所有能量范围。
实验研究表明，RGD有潜力用于治疗性质子束的剂量测定，包括端到端剂量测定。
