BMS-IMRT与三维适形放疗在宫颈癌术后放疗中的剂量学优势及对危及器官的影响

The Dosimetry Advantage of BMS-IMRT and Three-dimensional Conformal Radiation Therapy in Postoperative Radiotherapy of Cervical Cancer and Their Effects on Organs at Risk

目的 比较骨髓单独限量调强适形放疗(BM S-IM RT)与三维适形放疗(3D-CRT)在宫颈癌术后全盆腔放疗中的剂量学差异,并探讨对危及器官(OARs)的影响。方法 回顾性分析2018年8月至2020年8月本院收治的40例宫颈癌术后行全盆腔放疗患者的临床病例资料,根据术后放疗方式不同分为BMS-I MRT组(n=16)与3D-CRT组(n=24),BMS-IMRT组接受BMS-IMRT计划,3D-CRT组接受3D-CRT计划。比较2组靶区剂量分布,OARs的剂量学差异以及骨髓抑制情况。结果 BMS-IMRT组和3D-CRT组的D_(95)[(44.78±0.42) vs (44.61±0.57)]、V_(95)[(99.40±2.73) Vs(99.07±5.26)]比较,均无统计学差异(P>0.05);BMS-IMRT组的均匀指数(HI)[(1.07±0.04) vs (1.11±0.02)]/适形指数(CI)[(0.67±0.10) vs (048±0.07)]均优于3D-CRT组,差异有统计学意义(P<0.06);3D-CRT组直肠、膀胱、小肠的V_(40),小肠V_(35),骨髓V_(20)和骨髓V_(10)均明显高于BMS-IMRT组(P<0.05);BMS-IMRT组Ⅱ级及以上骨髓抑制的比例明显低于3D-CRT组[66.67%vs 31.25%](P<0.05)。结论 宫颈癌术后全盆腔放疗中,BMS-IMRT计划在保证靶区剂量前提下,更有助于保护危及器官,改善骨髓抑制情况。

Objective To compare the dosimetry differences between bone marrow-sparing intensity modulated radiation therapy(BMS-IMRT) and three-dimensional conformal radiation therapy(3D-CRT) in total pelvic radiotherapy after cervical cancer surgery,and to explore the effects on organs at risk(OARs).Methods A retrospective analysis was performed on the clinical case data of 40 patients undergoing total pelvic radiotherapy after cervical cancer surgery who were admitted to the hospital from August 2018 to August 2020.According to different postoperative radiotherapy methods,they were divided into BMS-IMRT group(n=16,BMS-IMRT) and 3D-CRT group(n=24,3D-CRT).The target dose distribution,dosimetry differences of OARs and bone marrow suppression between the two groups were compared.Results There was no significant difference in D95[(44.78±0.42) vs(44.61±0.57)]and V_(95)[(99.40±2.73) vs(99.07±5.26)] between BMS-IMRT group and 3D-CRT group(P>0.05).The homogeneity index(HI) [(1.07±0.04) vs(1.11±0.02)] and conformal index(CI) [(0.67±0.10) vs(0.48±0.07)] in BMS-IMRT group were better than those in 3D-CRT group(P<0.05).V_(40) of rectum,bladder and small intestine,V_(35) of small intestine,V_(20) and V_(10) of bone marrow in 3D-CRT group were significantly higher than those in BMS-IMRT group(P<0.05).The proportion of cases with bone marrow suppression at grade Ⅱ and above in BMS-IMRT group was significantly lower than that in 3D-CRT group [66.67% vs 31.25%](P<0.05).Conclusion In total pelvic radiotherapy after cervical cancer surgery,BMS-IMRT is more beneficial to protect OARs and improve bone marrow suppression under the premise of ensuring the target dose.