乳癌術中放射線治療之劑量均勻度評估

近年來隨著術中放射治療(intraoperative radiotherapy, IORT)技術的引進與進步，成為患者與醫生對於早期乳癌患者的首要治療選項。對於術中放射治療技術的劑量均勻性已經受到患者和醫師的質疑。本研究開發出左乳含有 30 cm3空腔的侖道假體，並以壓克力(polymethylmethacrylate, PMMA)製成。熱發光劑量計（Thermoluminescent dosimetry , TLD）方法用於評估 20 Gy，50 kV，在利用 Xoft Axxent 放射治療儀暴露於 IORT 的輻射下的輻射劑量。劑量在氣球型裝療器(balloon applicator)表面時為 20 Gy，在距離管球表面 0.7cm 處，劑量為 17.04 Gy，有明顯的下降。在距離管球表面 1.2cm 處，劑量為 6.88 Gy，下降更明顯。這項研究將是有用的，可以被推薦給患者親屬、醫師、放射師，和主管機關參酌。

In recent years, the newly developed intraoperative radiotherapy (IORT) is the first choice for early breast cancer patients. Radiation homogeneity of this technique have been questioned to the patients and physicians. A left breast with a 30 cm3 cavity of Rando phantom had been developed and made of polymethylmethacrylate (PMMA). Thermoluminescent dosimetry (TLD) approach was used to evaluate radiation doses under 20 Gy, 50 kV of Xoft Axxent exposure of extra radiations undergoing IORT. Doses was 20 Gy at the surface of balloon applicator, 17.04 Gy was found at the 0.7 cm away from surface, and dropped apparently. More clearly dropped, 6.88 Gy was indicated at the 1.2 cm away from surface. This study will be useful and recommended to the relatives, physicians and radiologists and authorit.