用MOSFET探测器进行乳腺癌放疗剂量的实时检测

目的 研究用金属氧化物半导体场效应晶体管(MOSFET)探测器测量接受高能X射线半束照射的乳腺癌患者的照射剂量。方法 采用MOSFET探测器首先在人体模型上测量,研究在6MV X射线半束照射中相邻半野剂量的分布情况和加速器相关因子的影响,然后实时测量10例乳腺癌患者腋锁野与胸壁切线野6MVX射线半束照射时匹配线上、腋锁...

In vivo measurement of radiation dose during radiotherapy in breast cancer patients using MOSFET dosimeter

Objective The purpose of the study was to observe and analysis the actual dosage of patients with breast cancer using metal oxide semiconductor field effect transistor (MOSFET) detector.Methods First, Phantom measurements were performed to investigate dose distribution in the area of the junction in a half-field matching method and the influence of factors related to the accelerator. In vivo dose measurements were performed for patients with breast cancer to investigate the skin dose and the junction of supraclavicular-axillary field and tangential field in 6 MV X-ray beams. Results Phantom measurements showed that the relative deviation in the junction were within + 3％, and the dose distributions in the junction area depended on the matching field direction (x or y). In vivo measurement of tangential region for patients showed that, the maximum dose deviation between measurement and calculation was -30. 39％,the minimum deviation was - 18. 85％, the average dose deviation was -24. 76％. The dose deviation of tangential fields for patients with breast-conserving surgery was larger than that patients with radical surgery (t =2. 40 ,P＜0. 05), while dose deviation of supraclavicular-axillary fields was not significantly different. The average values of 15 fraction in the junction area showed more stable than one individual measurement.Conclusions It is important to real-time, in vivo measurement of radiation dose during radiotherapy in patients with breast cancer, and change treatment plan in time, to ensure the accuracy of target dose.