容积旋转调强与固定野调强在宫颈癌根治性放疗中的效果比较

Volumetric modulated arc therapy versus fixed-field intensity-modulated radiotherapy in radical radiotherapy for cervical cancer

目的比较容积旋转调强(VMAT)与固定野调强(f-IMRT)根治性放疗的优缺点。方法回顾性分析接受f-IMRT和VMAT放疗的43例宫颈癌患者的临床资料,比较2组的剂量学参数、临床不良反应及疗效。结果 VMAT计划组的适形度指数(CI)高于f-IMRT组,治疗时间短于f-IMRT组,差异均有统计学意义(P <0.05或P <0.01),2组其余剂量学参数如最大剂量(Dmax)、平均剂量(Dmean)、均匀性指数(HI)和机器调数(MU)比较,差异无统计学意义(P> 0.05)。VMAT计划组的小肠V30、V40、V50,膀胱V50,直肠V40低于f-IMRT计划组,差异有统计学意义(P <0.05)。2组Ⅰ、Ⅱ级消化道不良反应发生率比较,差异有统计学意义(P <0.05)。结论相较f-IMRT计划,VMAT计划具有更好的适形性,能更好地保护正常组织如小肠、膀胱,并明显缩短治疗时间,是较好的宫颈癌外照射放疗计划。

Objective To compare the advantages and disadvantages of volumetric modulated arc therapy (VMAT) and fixed-field intensity-modulated radiotherapy (f-IMRT) in radical radiotherapy for cervical cancer. Methods Clinical materials of 43 cervical cancer patients with VMAT and f-IMRT were analyzed retrospectively. Dosimetric parameters,the clinical complications and efficacy were compared between two groups. Results The conformity index (CI) of VMAT plan group was higher than that of f-IMRT plans group,and no significant differences were found in other dosimetric parameters such as maximum dose (Dmax),average dose (Dmean),homogeneity index (HI) and machine tuning (MU). VMAT plan group resulted in reductions in V30,V40,V50 of intestine,V40 of rectum and V50 of the bladder (P < 0. 05). There were significant differences between the two groups in grade Ⅰ and Ⅱ gastrointestinal side effects. Conclusion Compared with f-IMRT plan,VMAT plan has a better conformability,which can better protect normal tissues such as small intestine and bladder as well as significantly shorten treatment time,so it is a better option for external radiotherapy for cervical cancer.