HT全脑+病灶同步推量放疗多发性脑转移瘤剂量学及临床分析

摘要

目的 回顾分析应用HT行全脑+病灶同步推量治疗多发性脑转移瘤患者的剂量学数据及临床结果,评估计划合理性及HT治疗的疗效与安全性.方法 2014-2017年共43例脑转移患者(≥3个病灶)纳入分析.全脑40 Gy分20次,病灶60 Gy分20次.疗中复查脑MRI,如病灶缩小则缩野.以TC、CI、PITV、HI进行计划评估.临床观察指标包括LRFS、IPFS、PFS、OS和不良反应.结果 中位病灶数为6个(3～ 36个),中位病灶总体积8.74 cm3.病灶TC、CI、PITV和HI分别为0.96±0.028、0.51±0.164、2.09±1.245和0.12±0.066.全脑TC和HI分别为0.95±0.033和0.43±0.161.26％患者进行疗中缩野,二程计划危及器官受量降低.1年LRFS、IPFS、PFS和OS分别为96％、80％、39％和86％.无≥3级不良反应发生.结论 HT技术实施全脑+病灶同步推量放疗计划适形度、均匀度好,治疗安全有效,可作为多发性脑转移瘤患者优选治疗方案,疗中缩野可更好地保护正常组织.%Objective To retrospectively analyze the dosimetry and efficacy of whole-brain irradiation (WBRT) with simultaneous integrated boost (SIB) by helical tomotherapy (HT) in the treatment of multiple brain metastases (BMs),and to evaluate the feasibility,efficacy,and safety of HT.Methods From 2014 to 2017,a total of 43 patients with multiple BMs (no less than 3 lesions) were enrolled as subjects.A dose of 40 Gy was delivered to the whole brain in 20 fractions,while a dose of 60 Gy was delivered to the gross target volume (GTV) in 20 fractions.Patients were reexamined by magnetic resonance imaging during treatment.The radiation field would be shrunk if GTV was reduced.Target coverage (TC),conformity index (CI),prescription isodose/target volume (PITV) ratio,and homogeneity index (HI) were assessed.Clinical indices included local recurrence-free survival (LRFS),intracranial progression-free survival (IPFS),progression-free survival (PFS),overall survival (OS),and toxicities.Results The median lesion number was 6(3-36) and the median total volume of GTV was 8.74 cm3.The TC,CI,PITV,and HI for GTV were 0.96±0.028,0.51±0.164,2.09±1.245,and 0.12±0.066,respectively,while the TC and HI for the whole brain were 0.95±0.033 and 0.43±0.161,respectively.In all the patients,26％ had replarming during treatment.The two-stage treatment reduced the radiation dose to organs at risk.The 1-year LRFS,IPFS,PFS,and OS rates were 96％,80％,39％,and 86％,respectively.No grade ≥3 toxicities were observed.Conclusions WBRT with SIB by HT achieves satisfactory conformity,homogeneity,efficacy,and safety,which is a recommended treatment plan for multiple BMs.Replanning during treatment can better protect normal tissue.