PDF(Pubmed)
Abstract：
The ZAP-X represents the first-of-its-kind \"self-shielded\" therapeutic radiation device, which by novelty, challenges regulators to accommodate it within the existing regulatory framework for radiation protection. To facilitate informed regulatory interpretation, X-ray radiation leakage from the ZAP-X was measured inside the shielded treatment capsule at the level of the patient and X-ray target plane. Measurements were performed on a clinically commissioned system calibrated for reference conditions to deliver 1cGy/MU. Radiation was measured with a FLUKE 451 survey meter and a RadCal ionization chamber as both exposure and dose and presented as a percentage of the system reference dose. Measurements were taken at thirteen locations, eight in the patient plane and five in the X-ray target plane. The results showed a maximum X-ray leakage of 0.000986% in the patient plane and 0.000907% in the target plane. These results are 30 - 100 times lower than existing recommendations as referenced by IEC guidelines standard 60601-2-1 (2020) for radiotherapy linear accelerators (LINACs). Although most conventional LINACs apply a safety factor of 2-5 to the design of collimator shielding and patient dose sparing, the ZAP-X delivers less than 10% of the patient whole body dose compared to this standard, originating from the X-ray target. Even though the ZAP-X intensity modulated radiation therapy (IMRT) factor is significantly higher than conventional Linacs, the absolute dose originating from leakage radiation remains lower by 25. The amount of unintended dose received by the patient\'s body distant from the isocenter is of interest from the perspective of both clinical and radiation safety. As this whole-body dose is decreased, the resulting treatment-related cancer incidence and mortality rates are decreased accordingly.
摘要：
ZAP-X代表了同类中的第一个“自屏蔽”治疗放射装置，由于新奇，挑战监管机构将其纳入现有的辐射防护监管框架。为了促进知情的监管解释，在患者和X射线靶平面的水平处,在屏蔽治疗胶囊内部测量来自ZAP-X的X射线辐射泄漏。在针对参考条件校准的临床调试系统上进行测量以递送1cGy/MU。用FLUKE451测量仪和RadCal电离室测量辐射作为暴露量和剂量，并以系统参考剂量的百分比表示。在十三个地点进行了测量，患者平面中有8个，X射线目标平面中有5个。结果显示，患者平面中的最大X射线泄漏为0.000986％，目标平面中的最大X射线泄漏为0.000907％。这些结果比用于放射治疗直线加速器(LINAC)的IEC指南标准60601-2-1(2020)所引用的现有建议低30-100倍。尽管大多数传统的LINAC将2-5的安全系数应用于准直器屏蔽和患者剂量节约的设计，与该标准相比，ZAP-X提供的患者全身剂量不到10%，来自X射线目标。尽管ZAP-X调强放射治疗（IMRT）因子明显高于传统的Linacs，来自泄漏辐射的绝对剂量仍然低25。从临床和放射安全性的角度来看，患者身体远离等中心的非预期剂量是令人感兴趣的。随着全身剂量的减少，由此导致的与治疗相关的癌症发病率和死亡率相应降低。
