一种简单调强放疗技术的初步应用研究

耿辉 戴建荣 李晔雄 张可 王绿化

作者单位：中国医学科学院(协和医科大学)

肿瘤医院(肿瘤研究所)放射治疗科

100021 北京

通信作者：戴建荣　　　

[摘要] 目的 介绍一种简单调强放疗技术(简称sIMRT)。方法 sIMRT技术是指单射野的子野数目平均不超过5个、子野面积不小于10cm²、子野照射机器跳数不低于10MU的调强放疗技术。该技术应用过程中的计划设计和治疗实施环节与IMRT相同，但考虑到其子野面积和子野机器跳数已接近经典适形技术(CRT)的相应值，其计划验证环节可与经典适形技术(CRT)相同。该技术的应用过程和应用效果用一例直肠癌病例做了演示。结果 对于直肠癌，sIMRT计划在靶区均匀性及对危及器官的保护方面均显著优于CRT计划，但稍逊于IMRT计划。sIMRT计划的治疗实施时间与CRT计划相当，大约是IMRT计划的一半。我院临床应用情况表明，该技术可广泛应用于胸腹部肿瘤，如肺癌、食管癌和前列腺癌。结论 sIMRT适用于CRT不能满足临床要求，而多于25个子野的IMRT又不能进一步显著改善计划质量的情况，为临床实际工作提供了一个新的性价比高的解决方案。

[关键词] 简单调强 调强放疗 适形放疗

A simple IMRT technique

GENG Hui , DAI Jianrong , LI Yexiong, ZHANG Ke, WANG Luhua

Department of Radiation Oncology

Cancer Institute (Hospital)

Chinese Academy of Medical Science (Peking Union Medical College)

Beijing 100021, China

Corresponding author: DAI Jianrong

[Abstract] Objective To introduce a simple IMRT technique (sIMRT). Methods and Material For sIMRT, the average number of segments per beam should be no more than 5. The segment area is no less than 10cm², and the number of machine monitor for each segment is no fewer than 10. In its application process, treatment planning procedure and treatment delivery procedure are the same as those of IMRT. However, the treatment verification procedure can be set as that of classic conformal radiotherapy (CRT), because the area and number of monitor units of each segment are close to those values for CRT. The application of sIMRT is demonstrated in a patient with rectum cancer.

Results For rectum case, in terms of target dose uniformity and sparing of organs at risk, sIMRT plan is significantly superior to CRT plan, but slightly inferior to IMRT plan. In terms of treatment delivery time, sIMRT plan is almost the same as CRT plan. Compared with CRT, sIMRT does not use wedges, and consequently, it alleviates the labor intensiveness and fully avoids accidents of wedge falloff. Its application in our clinic shows that it mainly applies to thoracic and abdominal tumors (e.g. lung, esophagus and prostate cancers). Conclusions sIMRT is applicable to the situation that CRT is unable to meet clinical requirements and IMRT with more than 25 segments can not significantly improve the treatment outcome. It provides a clinical solution with high ratio of performance-to-cost.

[Key words] Simple IMRT, intensity-modulated radiation therapy，conformal radiotherapy