以熱發光劑量計全因子實驗最佳化評估中山醫學大學附設醫院多模式螺旋斷層放射治療儀之環境輻射

從古至今，癌症一直是國人十大死因之首。多模式螺旋斷層放射治療儀(TomoTherapy)具有影像導引、立體定位等特點，可有效控制腫瘤並降低治療相關的副作用。現今台灣中山醫學大學附設醫院(Chung Shan Medical University, CSMUH)每月進行治療的病人約350人，每次治療所需15～20分鐘、以6 MV的輻射能量放出。本研究使用熱發光劑量計TLD-100H(Thermoluminescent dosimeter, TLD)，使用亞瑟刀(Elekta Axesse)對熱發光劑量計進行篩選和校正，並藉由全因子設計(Full factorial design)得到最佳化計讀參數。使用經篩選後的TLD對Tomo進行了為期七個月的佈點測量和為期一個月的三次測量。最佳參數設定組為初始溫度為130 ℃，加熱速率為11 ℃/s，最高溫度為230 ℃。Tomo治療室內檢測到的最高暴露輻射為1730±140 mSv/mo，得到治療室旁的各辦公室、等候區等區域劑量皆為背景值。滑動安全門的有效阻擋為650倍，證明鉛滑門與混凝土牆，可以充分保護工作人員和家屬。利用本實驗希望透過所獲得的結果，改善工作人員、病人與家屬輻射安全上的防護，進而替操作人員與病人達到暴露之合理抑低。這項研究表明了Tomo對周圍區域沒有額外輻射傷害。

TomoTherapy has the characteristics of image guidance, stereo positioning, etc., which can effectively control tumors and reduce treatment-related side effects. The Chung Shan Medical University hospital (CSMUH) in Taiwan treats about 350 patients every month. Each treatment takes 15-20 minutes and emits 6 MV of radiation energy each time. In this study, the Thermoluminescent dosimeter (TLD) was used, and the Axesse was used to select and calibrate the TLD-100H, and the Full factorial design was used to optimize its reading parameter. Using the TLD after selecting, Tomo was measured for seven months and three times for one month. The best parameter setting group is that the initial temperature is 130 ℃, the heating rate is 11 ℃/s, and the maximum temperature is 230 ℃. The highest exposure radiation detected in the treatment room is 1730±140 mSv/mo, and the doses in the surrounding area of Tomotherapy are all background values. This experiment hopes to use the results obtained to improve the radiation safety protection of staff, patients and their families, and to achieve a reasonable reduction in exposure for operators and patients. This study shows that Tomo has no additional radiation damage to the surrounding area.