應用雷射掃瞄系統於聚合物凝膠劑量計之劑量評估

Implementation of Laser Scanning System Applied on Dose Evaluation of Polymer Gel Dosimeter

郭佳瑋(Chia-wei Kuo)

指導教授 ： 張淵仁

中臺科技大學/健康科學院/醫學工程暨材料研究所/碩士(2008年)

摘要

凝膠劑量計為偵測3D立體劑量分佈之工具，能評估治療計畫。為能準確評估劑量分佈，本研究建立一套雷射掃描系統於聚合物凝膠劑量計來進行劑量量測。

本研究以波長632.8 nm He-Ne雷射搭配光度計，計算雷射穿透聚合物凝膠後的衰減係數。量測SIGMA、WAKO與DEMA三種聚合物凝膠，並與MRI量測結果進行比較。

本研究有以下結論：
1.以632.8 nm He-Ne雷射為量測光源，成功建立一套量測系統，本系統量測不準確度為2.97 % 。
2.本系統量測SIGMA單體凝膠，最佳線性劑量落於0-10 Gy，線性度為 0.996，敏感度為 0.0196。
3.本系統量測WAKO單體凝膠，最佳線性劑量落於0-10 Gy，線性度為0.996，敏感度為 0.0288。
4.本系統量測DEMA單體凝膠，最佳線性劑量落於0-30 Gy，線性度為 0.996，敏感度為 0.001。
5.與MRI量測結果相較，SIGMA單體凝膠最佳線性劑量落於0-15 Gy,線性度為0.993，敏感度為0.1029。WAKO單體凝膠最佳線性劑量落於0-15 Gy,線性度為0.993，敏感度為0.1112。
6.以不同雷射光強度進行SIGMA、WAKO與DEMA單體凝膠量測，其劑量反應曲線結果相同。

關鍵字

劑量計 ； 雷射掃描系統 ； 聚合物凝膠

並列摘要

Gel dosimeter is used to measure 3-Dimensional dose distribution. It can evaluate the treatment planning. In this study, in order to improve the accuracy of measurement, a laser scanning system was developed and was applied on the dose measurement of polymer gel dosimeter
In this study, by using a He-Ne laser with wavelength 632.8 nm, attenuation coefficient of polymer gel can be calculated from the optical intensity measured by optical power meter. Three polymer gels was measured including SIGMA, WAKO, and DEMA. In addition, the measurement results were compared with that by MRI measurement.

The conclusions can be described as follows:
1.A laser scanning system is well-established and the uncertainty of this system is less than 2.97 %.
2.For SIGMA gel, the best linear dose range is from 0 to 10 Gy. The linearity is 0.996 and the sensitivity is 0.0196.
3.For WAKO gel, the best linear dose range is from 0 to 10 Gy. The linearity is 0.996 and the sensitivity is 0.0288.
4.For DEMA gel, the best linear dose range is from 0 to 30 Gy. The linearity is 0.996 and the sensitivity is 0.001
5.From the results of MRI, for SIGMA gel, the best linear dose range is from 0 to 15 Gy. The linearity is 0.995 and the sensitivity is 0.1029. For WAKO gel, the best linear dose range is from 0 to 15 Gy. The linearity is 0.993 and the sensitivity is 0.1112.
6.The measurement results of each gel are similar by using various optical intensities.

並列關鍵字

dosimeter ； polymer gel ； laser scanning system

參考文獻

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