Silvestre Patallo Ileana, Subiel Anna, Carter Rebecca, Flynn Samuel, Schettino Giuseppe, Nisbet Andrew
Medical Radiation Physics and Science Groups, National Physical Laboratory (NPL), Guilford TW11 0LW, UK.
Cancer Institute, University College London, London WC1E 6DD, UK.
Cancers (Basel). 2023 Feb 3;15(3):987. doi: 10.3390/cancers15030987.
The purpose of the study was to characterize a detection system based on inorganic scintillators and determine its suitability for dosimetry in preclinical radiation research. Dose rate, linearity, and repeatability of the response (among others) were assessed for medium-energy X-ray beam qualities. The response's variation with temperature and beam angle incidence was also evaluated. Absorbed dose quality-dependent calibration coefficients, based on a cross-calibration against air kerma secondary standard ionization chambers, were determined. Relative output factors (ROF) for small, collimated fields (≤10 mm × 10 mm) were measured and compared with Gafchromic film and to a CMOS imaging sensor. Independently of the beam quality, the scintillator signal repeatability was adequate and linear with dose. Compared with EBT3 films and CMOS, ROF was within 5% (except for smaller circular fields). We demonstrated that when the detector is cross-calibrated in the user's beam, it is a useful tool for dosimetry in medium-energy X-rays with small fields delivered by Image-Guided Small Animal Radiotherapy Platforms. It supports the development of procedures for independent "live" dose verification of complex preclinical radiotherapy plans with the possibility to insert the detectors in phantoms.
本研究的目的是对基于无机闪烁体的检测系统进行特性描述，并确定其在临床前放射研究中用于剂量测定的适用性。针对中能X射线束质评估了响应的剂量率、线性和重复性（以及其他方面）。还评估了响应随温度和束入射角的变化。基于与空气比释动能二级标准电离室的交叉校准，确定了与吸收剂量质量相关的校准系数。测量了小的准直野（≤10 mm×10 mm）的相对输出因子（ROF），并与Gafchromic胶片和CMOS成像传感器进行了比较。与束质无关，闪烁体信号的重复性良好且与剂量呈线性关系。与EBT3胶片和CMOS相比，ROF在5%以内（较小的圆形野除外）。我们证明，当探测器在用户的射束中进行交叉校准时，它是一种用于剂量测定的有用工具，可用于图像引导小动物放射治疗平台提供的小射野中能X射线。它支持开发用于复杂临床前放射治疗计划独立“实时”剂量验证的程序，并且有可能将探测器插入模体中。
