目的：利用電腦斷層掃描凝膠劑量分布臨床實用性。 材料與方法：使用直線加速器（Varian Clinic iX，美國）作為射源，照射 NIPAM 聚合物凝膠劑量 計，凝膠聚合反應完成後使用 X-ray 電腦斷層掃描儀（HiSpeed GE，美國）擷取切面凝膠影像， 利用 Matlab（The MathWorks, Natick, MA, USA）軟體分析凝膠之切面影像，比較治療計畫與 NIPAM 凝膠劑量計之γ 測試。 結果：結果呈現使用多張 CT image 計算影像平均 CT 值，可以大幅降低 CT 雜訊，搭配利用聚合 物凝膠未照射當背景影像（Background image）減贅後，第一次實驗結果環狀假影消失γ 測試由 68.40% 提升至 95.02% 通過率。第二次實驗結果得到與 TPS 更為相近凝膠劑量分布，γ 測試的分 析結果為 97.57% 通過率。 結論與討論：該結果表明 X-ray 電腦斷層掃描儀是可以應用於臨床聚合物凝膠劑量驗證計讀工具 上。

Objectives : Using computed tomography (CT) scanning to evaluate the clinical applicability of intensity modulated gel dosimeter based on the dose distribution. Materials and Approaches : A Clinac iX linear accelerator (Varian, USA) was adopted as the radiation source to irradiate an N-isopropylacrylamide (NIPAM) polymer gel dosimetry. After the polymerization reaction, the gel was scanned using a HiSpeed CT scanner (GE, USA), and sliced images of the gel were analyzed using Matlab (MathWorks, Natick, MA, USA). Next, the gamma test obtained for the treatment plan and the NIPAM polymer gel were compared. Results : The results indicated that using numerous CT images to calculate the mean CT numbers of the images can substantially reduce CT noise. In addition, when the polymer gel was unilluminated and background subtraction occurred, the ring artifacts produced in the first experiment disappeared. Furthermore, the gamma test increased from 68.40% to 95.02% pass rate. The gel dose distribution yielded in the second experiment was similar to that of the treatment plan system, and the obtained gamma test was 97.57% pass rate. Discussion and Conclusion : The results showed that X-ray CT scanning can be applied to clinical polymer gel dosimeters.