容积旋转调强技术行全脑放疗联合转移灶同期加量治疗脑转移瘤的剂量学研究  

Whole-brain radiotherapy involving a simultaneous integrated boost to brain metastases using volumetric modulated arc therapy:a dosimetric study

作　　者：王中飞[1] 谭丽娜[1] 孙晓欢[1] 肖锋[1] 

机构地区：[1]第四军医大学西京医院放疗科,西安710032

出　　处：《中国癌症防治杂志》2017年第3期205-209,共5页CHINESE JOURNAL OF ONCOLOGY PREVENTION AND TREATMENT

基　　金：国家自然科学基金资助项目(81372422)

摘　　要：目的探讨容积旋转调强(volume modulated arc therapy,VMAT)技术行全脑放疗联合转移灶同期加量治疗脑转移瘤的可行性。方法选取10例行放疗的脑转移瘤患者,每例患者同时设计两种放疗计划:RA计划和Sum计划。RA计划全程采用VMAT技术,全脑照射30 Gy/10 F,同时转移灶同期加量照射45 Gy/10 F;Sum计划全脑适形对穿照射30 Gy/10F后,采用VMAT技术对转移灶局部加量照射15 Gy/5 F。比较两种计划的靶区剂量分布、危及器官及转移灶外脑组织的受照射剂量、机器跳数等。结果两种计划靶区剂量分布均满足临床要求。RA计划靶区适形度指数优于Sum计划(0.99±0.00 vs 0.77±0.05,P<0.001),全脑V35、V40亦显著小于Sum计划(P<0.05),机器跳数较Sum计划减少约12%。结论RA计划的靶区剂量分布可达到或优于Sum计划,能更好地降低转移灶外正常脑组织的受照射剂量,减少机器跳数。应用VMAT技术行全脑放疗联合转移灶同期加量是制定脑转移瘤放疗计划的一种优选方式。Objective To perform a dosimetry study of the RapidArc technique for whole-brain radiotherapy involving simultaneous integrated boost （SIB） to brain metastases （BM） using volumetric modulated arc therapy （VMAT）. Methods Ten patients diagnosed with brain metastases were randomly selected and two treatment plans were designed for each patient. The RA plan involved whole- brain VMAT （30 Gy） and SIB to BM （45 Gy） delivered in 10 fractions. The Sum plan involved whole-brain 3DCRT （30 Gy） and SIB with VMAT to BM （15 Gy） delivered in 5 fractions.Results were compared using dose-volume histogram analysis. Results Both plans met the clinical requirements.Target conformity was better for the RA plan （0.99±0.00） than for the Sum plan（0.77±0.05; P〈0.001 ）. V35 and V40to brain were significantly lower in the RA plan than in the Sum plan （P〈0.05）. Average monitor units were 12% smaller with the RA plan than with the Sum plan. Condusions The RA plan was similar to the Sum plan or better in terms of target dose distribution, monitor units and irradiation of some organs at risk, especially the normal brain tissue beside the metastases. These results suggest that whole-brain radiotherapy with SIB to BM using VMAT is superior for treating brain metastases.

关 键 词：容积旋转调强 脑转移瘤 全脑照射 剂量学 

分 类 号：R739.91[医药卫生—肿瘤] R730.55[医药卫生—临床医学]