目的：在使用新的強度調控放射治療技術治療腫瘤時，藉由放射膠片來做強度調控放射治療品質
保證，是非常重要的一項工作。本研究目的為對 GafChromic EBT 膠片進行一系列的特性測量及校正，並建立計讀的方式與程序，最後將膠片放置於口腔癌及舌癌病患口腔裡，度量其所接受之輻射劑量。
材料及方法：在研究的過程裡，先對 GafChromic EBT 膠片進行一系列的特性測量與校正並建立計讀程序，之後將膠片放置於固態水假體之參考點與直接放置在病人口腔內，來針對強度調控放射治療模式下測量其劑量，將其所得之劑量與治療計畫互相比較，經由使用這一種口腔輻射劑量度量方法，來驗證臨床上實際得到的照射劑量。
結果：在本研究中，假體進行強度調控放射治療模式照射，皆以靜態式 step-and-shoot 的方式照射以及以兩種不同之幾何照野照射來模擬病人，其一照野的測量結果比治療計畫多 2%，其二照野的測量結果比治療計畫少 3.7%。而在口腔輻射測量結果中，口腔癌病患測量結果與治療計畫相比，其平均誤差為 2.56%（+0.5%~+5.3%），而舌癌病患測量結果與治療計畫相比，其平均誤差為 -5.26%（-3.4%~-7.1%）。
結論：經由本實驗瞭解 GafChromic EBT 膠片之結構與特性，以及建立一套包括校正與計讀程
序，且建議在使用時所應該注意的事項，以降低誤差的發生。並藉由直接的方式，將膠片置放於
病患口腔內計讀其劑量，以達到品質保證的目的。

Purpose : The intensity modulated radiation therapy (IMRT) quality assurance (QA) by film is a very important job when using the new technique of IMRT to treat tumor. The aim of this study is first to measure the characteristic of the GafChromic EBT film, calibration and establish a procedure of reading, then we do an oral cavity dosimetry for buccal and tongue cancers.
Materials and Methods : We use the new developed GafChromic EBT film for oral cavity dosimetry study in this work. First, we measure the characteristic of the film and establish a procedure for reading. Second, we put the film into the solid water phantom’s reference point and the patient’s oral cavity to do oral cavity dosimetry for IMRT. We have compared the results with treatment planning system. Our oral cavity dosimetry can verify the real tumor dose in clinic situation.
Results : The measured dosimetry results for solid water phantom are 2% more than treatment planning system in case one, and 3.7% less than treatment planning system in case two. For oral cavity dosimetry, the error is 2.56% for buccal cancer and 5.26% for tongue cancer.
Conclusion : By this study, we can understand the structure and characteristic of this newly developed film as well as establish procedure of calibration and readings. In order to reduce error and increase
accuracy, we also made suggestions for using this film to do dose measurements. Through patient oralcavity dosimetry, we can achieve the goal of quality assurance.