Chen Chiu-Ping, Lin Chi-Yeh, Kuo Chia-Chun, Chen Tung-Ho, Lin Shao-Chen, Tseng Kuo-Hsiung, Cheng Hao-Wen, Chao Hsing-Lung, Yen Sang-Hue, Lin Ruo-Yu, Feng Chen-Ju, Lu Long-Sheng, Chiou Jeng-Fong, Hsu Shih-Ming
Department of Radiation Oncology, Wan Fang Hospital, Taipei Medical University, Taipei 110, Taiwan.
Department of Biomedical Imaging and Radiological Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan.
Cancers (Basel). 2022 Jun 30;14(13):3205. doi: 10.3390/cancers14133205.
Breast immobilization with personalized breast holder (PERSBRA) is a promising approach for normal organ protection during whole breast radiotherapy. The aim of this study is to evaluate the skin surface dose for breast radiotherapy with PERSBRA using different radiotherapy techniques.
We designed PERSBRA with three different mesh sizes (large, fine and solid) and applied them on an anthropomorphic(Rando) phantom. Treatment planning was generated using hybrid, intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques to deliver a prescribed dose of 5000 cGy in 25 fractions accordingly. Dose measurement with EBT3 film and TLD were taken on Rando phantom without PERSBRA, large mesh, fine mesh and solid PERSBRA for (a) tumor doses, (b) surface doses for medial field and lateral field irradiation undergoing hybrid, IMRT, VMAT techniques.
The tumor dose deviation was less than five percent between the measured doses of the EBT3 film and the TLD among the different techniques. The application of a PERSBRA was associated with a higher dose of the skin surface. A large mesh size of PERSBRA was associated with a lower surface dose. The findings were consistent among hybrid, IMRT, or VMAT techniques.
Breast immobilization with PERSBRA can reduce heart toxicity but leads to a build-up of skin surface doses, which can be improved with a larger mesh design for common radiotherapy techniques.
使用个性化乳房固定器(PERSBRA)进行乳房固定是全乳放疗期间保护正常器官的一种有前景的方法。本研究的目的是评估使用不同放疗技术的PERSBRA全乳放疗的皮肤表面剂量。
我们设计了三种不同网格尺寸(大、细和实心)的PERSBRA,并将它们应用于拟人化(兰多)体模。使用混合、调强放疗(IMRT)和容积调强弧形放疗(VMAT)技术进行治疗计划,相应地在25次分割中给予规定剂量5000 cGy。使用EBT3胶片和热释光剂量计(TLD)在没有PERSBRA的兰多体模、大网格、细网格和实心PERSBRA上进行剂量测量,测量内容包括(a)肿瘤剂量,(b)采用混合、IMRT、VMAT技术进行内侧野和外侧野照射时的表面剂量。
在不同技术中,EBT3胶片和TLD的测量剂量之间的肿瘤剂量偏差小于5%。PERSBRA的应用与皮肤表面剂量较高相关。PERSBRA的大网格尺寸与较低的表面剂量相关。这些结果在混合、IMRT或VMAT技术中是一致的。
使用PERSBRA进行乳房固定可降低心脏毒性,但会导致皮肤表面剂量增加,对于常见放疗技术,采用更大的网格设计可改善这一情况。