以動態田口最佳化評量TLD計讀儀

熱發光劑量計是一種可以重複使用而且可以應用到不同劑量的工具，可以利用在環境或臨床上的劑量測量。本研究利用動態田口分析法，評量計讀熱發光劑量計（Thermoluminescent dosimeter , TLD）參數設定對於TLD曝露於1、10、100 cGy後TLD之計讀所得到的訊號的影響。在此使用的因子及找到最佳化的參數設定為儲藏溫度為-11 °C；起始溫度為120 ℃；加熱速率為3 ℃/s ；最大溫度為240 ℃；最後 TLD經過曝露後到計讀時間為40 hr。最後使用肺癌放射治療來驗證田口法找到的最佳化參數設定的正確性，而驗證結果為本研究成功優化在低劑量區域的計讀條件。田口分析法中的因子反應分析也找出本研究主要因子既是最大溫度與加熱速率，而儲藏溫度、起始溫度、TLD經過曝露至計讀時間為次要因子。

Thermoluminescence dosimetry (TLD) is a powerful approach with wide applications in various therapies, such as environmental and clinical dosimetry. The 6 MV radiotherapy beam was produced from an Axcess linear accelerator (LINAC). The beam doses were 1, 10, 100 cGy measured in each group were averaged from three TLDs. A total of eighteen combinations of five parameters were arranged, suggested by Taguchi. The five parameters were defined as storage temperature (℃), initial temperature (℃), heating rate (℃/s), maximum temperature (℃), and time of exposure to readout (hr). The optimized values were: (1) -11 ℃ for storage temperature, (2) 120 ℃ for initial temperature, (3) 3 ℃/s for heating rate, (4) 240 ℃ for maximum temperature, (5) 40 hours for the time of exposure to the readout herein. The dominant factors were maximum temperature, whereas storage temperature, initial temperature, heating rate, and time of exposure to readout were minor and provided negligible contributions to the system performance optimization. The Taguchi method also finds out that the maximum temperature and time of exposure to readout time are weak interactions, and the initial temperature and maximum temperature are strong interactions. Using the optimum protocol obtained by the Taguchi method, the dosimetry can be effectively performed with great accuracy.