肝癌立体定向体部放射治疗的剂量学研究

Dosimetry study of SBRT in primary hepatocellular carcinoma(PHC)

目的:探讨立体定向体部放射治疗(stereotactic body radiotherapy,SBRT)在原发性肝癌(Primary he-patic carcinoma,PHC)放疗中的剂量学特点和临床价值,证实SBRT是PHC放射治疗的发展方向。方法:2009年1月至8月,可行放疗的PHC患者50例,CT薄层定位扫描,将图像分别输入SBRT和三维适形放射治疗(3DCRT)计划系统,同一病例做两个治疗计划,对靶区内剂量分布、危及器官(OARs)受量、适形度等进行对比。结果:SBRT计划中靶区剂量显著高于3DCRT,正常肝脏和邻近OARs的重要剂量学指标均显著性低于3DCRT,两计划中适形指数(CI)和病灶覆盖率(Coverage)无统计学差异(P>0.05),均匀指数(HI)对比差异有显著性(P<0.05)。SBRT治疗后3个月左右复查CT,观察疗效。50例患者均完成治疗和接受随访复查,局部控制率为88%,半年、1年生存率分别为86%、70%。不良反应少且轻,经处理可缓解消失。结论:SBRT在肝癌放疗中具有明显的剂量学优势,值得推广运用。

Objective： To investigate the dosimetric advantages and the clinical value of stereotactic body radiotherapy（SBRT） in hepatocellular carcinoma（PHC） radiotherapy,and conform that SBRT is the future trends of PHC radiotherapy.Methods：All 50 PHC patients according to the radiotherapy indications were elected,and the images were imported into SBRT and three-dimensional conformal radiation therapy（3DCRT） treatment planning system after CT scan.Then two different treatment plans were devised for each case.The dose distribution of target areas,the dose of organs at risk（OARs） and the conformal degree were compared.Results：The target dose of SBRT planning was significantly higher than 3DCRT,but the important dose indexes of normal liver and OARs were significantly lower than 3DCRT.The conformal index（CI） and the lesion coverage（Coverage） were not statistically significant,but the heterogeneity index（HI） was.A CT scan was made for each patient after having been treated for 3 months according to SBRT plan,and the recent effect of SBRT in PHC was observed.The 50 patients had been completed the treatment and accepted the follow-up review.The local control rate was 88%,and the survival rates of six months and one year were 86% and 70% respectively.A few and mild side effects can be alleviated by effective treatment.Conclusion：The SBRT in PHC has the obvious dosimetric advantages and popularization value.