使用照野中之照野以及不規則體表補償器於乳癌病人放射治療之假體皮膚劑量量測

The Measured Skin Dose of the Simulated Phantom for Breast Cancer Patients Treated with Field-in-Field (Fif ) and Irregular Surface Compensator (Isc )

傅筱如(Hsiao-Ju Fu) ； 張瀞予(Ching-Yu Chang) ； 蔡維達(Wei-Ta Tsai) ； 曾玉華(Yuk-Wah Tsang) ； 張志嘉(Chih-Chia Chang)

《放射治療與腫瘤學》 22卷2期 (2015/06) Pp. 139-146

https://doi.org/10.6316/TRO/201522(2)139

摘要

目的：本實驗主要利用假體測量乳癌病人放射治療之表面劑量，以及評估乳癌病人皮膚劑量量測工具的可信度。材料與方法：本實驗採用薄片型熱發光劑量計以及輻射變色軟片來做為量測工具，並分別對其特性做研究；使用擬人假體（anthropomorphic Rando phantom）模擬測量自製乳房的表面劑量，利用Eclipse的治療計畫系統製作照野中之照野（Field-in-Field, FIF）和不規則體表補償器（Irregular surface compensator, ISC）的兩種技術作為治療的方法來做劑量分析，處方劑量為180 cGy。結果：本實驗之薄片型TLD變異係數在3%以內，計讀值與給予劑量間呈現良好線性關係；輻射變色軟片校正區線上每個點之變異係數在1%以內，整體校正曲線呈現穩定的關係；FIF和ISC利用EBT film和薄片型TLD兩種量測工具測量的表面劑量平均值分別為108.74 ± 14.86 cGy、107.35 ± 15.93 cGy和103.19 ± 12.91 cGy、102.09 ± 10.02 cGy；EBT film和薄片型TLD兩種量測工具在FIF的照射方式中測量自製乳房內側、中間、外側、上側、下側和全部的劑量誤差分別為5.17%、-3.45%、1.58%、1.27%、-0.55%和1.3%；EBT film和薄片型TLD兩種量測工具在ISC的照射方式中測量自製乳房內側、中間、外側、上側、下側和全部的劑量誤差分別為1.86%、2.94%、8.3%、-3.44%、-5%和1.08%。結論與討論：由本實驗得知，薄片型熱發光劑量計以及輻射變色軟片適合用來作為乳癌病人皮膚劑量的量測工具，未來本研究將統計臨床上人體出現皮膚反應時實際接受的劑量，以期測量到最準確的皮膚劑量並評估臨床不同皮膚反應時的皮膚毒性，確實找出造成病人皮膚反應的劑量評估值。

關鍵字

皮膚劑量 ； 薄片型熱發光劑量計 ； 輻射變色軟片

並列摘要

Purpose: This reasearch was focused on the measured surface dose of the simulated phantom for breast cancer patients treated with field-in-field (FIF) and irregular surface compensator (ISC) and the reliable measured tools to evaluate the skin dose of breast cancer patients. Materials and Methods: This experiment adopted 0.1mm ultrathin thermoluminescent dosimeters (ultrathin TLD) and ISP Gafchromic EBT film as the measured tool to establish the characteristics. Superficial doses of home-made breast on anthropomorphic Rando phantom were measured. FIF and ISC plans with a prescribed dose of 180 cGy were designed on this phantom using an Eclipse treatment planning system and using two measured tools to measure the absolute surface dose. Result: In this experiment the variance coefficient of TLD film was within 3%. The reading values and delivered doses were in a good linear relationship. The points on calibration curve of Gafchromic film were within 1% and in a stable performance. Mean surface measured doses of FIF and ISC with the EBT film and TLD film were 108.74 ± 14.86 cGy, 107.35 ± 15.93 cGy and 103.19 ± 12.91 cGy, 102.09 ± 10.02 cGy, respectively. The error between EBT film and TLD film for the inner, middle, outer, upper, lower regions of home-made breast and the total mean dose of FIF was 5.17%, -3.45%, 1.58%, 1.27%, -0.55% and 1.3%, respectively; the error between EBT film and TLD film for the inner, middle, outer, upper, lower regions of home-made breast and the total mean dose of ISC was 1.86%, 2.94%, 8.3%, -3.44%, -5% and 1.08%, respectively. Conclusion and Discussion: From the experimental results, ultrathin TLD and EBT film can be adopted as the measured tools for surface dose of breast cancer patients. The future work for this research could gather statistics of the skin reactions indeed affected by the skin dose received from radiation for clinical applications. To evaluate severity of skin reaction and measure most accurate skin dose, and this data can be used references for skin reaction gradings.

並列關鍵字

Skin dose ； Ultrathin TLD ； Gafchromic EBT film