俯卧位下直肠癌容积旋转调强及固定野调强的剂量学比较  

Dosimetric comparison between volumetric modulated arc therapy and fixed-field IMRT for rectal cancer on prone position

作　　者：张大伟[1] 覃文[1] 苏世达[1] 胡凯[1] 王仁生[1] ZHANG Dawei;QIN Wen;SU Shida(Department of Radiotherapy, the First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China)

机构地区：[1]广西医科大学第一附属医院放疗科,广西南宁530021

出　　处：《华夏医学》2018年第1期12-16,共5页Acta Medicinae Sinica

基　　金：广西卫生厅课题(Z2017559)

摘　　要：目的:比较单弧旋转调强(1-Arc)、双弧旋转调强(2-Arc)和七野调强(7-IMRT)在直肠癌放疗中的差异。方法:选取13例俯卧位放疗的直肠癌患者,设计1-Arc、2-Arc和7-IMRT计划,评估3种计划剂量学、机器跳数(MUs)及治疗时间的差异。结果:3种计划的靶区适形度相当。靶区均匀性1-Arc最差,2-Arc略好于7-IMRT。在膀胱、小肠和股骨头保护上2-Arc与7-IMRT无统计学差异(P>0.05),而1-Arc差于2-Arc和7-IMRT(P<0.05)。1-Arc、2-Arc、7-IMRT的MUs依次为(453.3±61.1)、(527.5±78.2)和(1293.6±160.3)。7-IMRT治疗时间最长,分别比1-Arc和2-Arc增加79.6%和61.2%。结论:3种计划均可达到临床要求,剂量学上2-Arc与IMRT相当且明显优于1-Arc。旋转调强技术可显著降低机器跳数和缩短治疗时间,提高治疗效率。Objective： To compare differences between 1 arc of volumetric modulated arc therapy（ 1-Arc）,2 arcs of volumetric modulated arc therapy（ 2-Arc） and seven-field intensity modulated radiotherapy（ 7-IMRT） in rectal cancer radiotherapy. Methods： The 1-Arc,2-Arc and 7-IMRT plans were designed for 13 patients with rectal cancer on prone position. The differences in dosimetry,machine jump numbers（ MUs）and treatment time were evaluated for the 3 plans. Results： The target area conformability of the 3 plans was equal. The target area uniformity of 1-Arc was the worst,and 2-Arc was slightly better than 7-IMRT. There was no significant difference between 2-Arc and 7-IMRT for doses to bladder,small intestine and femoral head（ P〉0.05）,but 1-Arc was far worse than 2-Arc and 7-IMRT（ P〈0.05）. MUs were（ 453.3 ± 61.1）,（ 527.5±78.2） and（ 1293.6±160.3）,respectively. The treatment time of 7-IMRT was 79.6% and 61.2% longer than 1-Arc and 2-Arc.Conclusion： The 3 plans all can achieve clinical demands,2-Arc had similar dose distribution as IMRT. Volumetric modulated arc therapy can significantly reduce MUs and treatment time.

关 键 词：直肠癌 调强放疗 容积旋转调强 剂量学 

分 类 号：R142[医药卫生—公共卫生与预防医学]