子宫颈癌保留双侧卵巢功能的放疗方法研究  

Study on radiotherapy method of preserving bilateral ovarian function for cervical cancer

作　　者：程晓龙[1] 吕晓娟[2] 刘吉平[1] 王彬冰[1] 唐秋[2] 潘林飞[1] 张莉[1] Cheng Xiaolong;Lv Xiaojuan;Liu Jiping;Wang Binbing;Tang Qiu;Pan Linfei;Zhang Li(Department of Radiation Physics,Zhejiang Cancer Hospital,Hangzhou 310022,China;Department of Gynecological Radiation Oncology,Zhejiang Cancer Hospital,Hangzhou 310022,China)

机构地区：[1]浙江省肿瘤医院放射物理室,浙江杭州310022 [2]浙江省肿瘤医院妇瘤放疗科,浙江杭州310022

出　　处：《实用肿瘤杂志》2019年第6期540-549,共10页Journal of Practical Oncology

基　　金：浙江省医药卫生科技项目(2015PYB068)

摘　　要：目的探讨基于调强放疗(intensity modulated radiation therapy,IMRT)、容积旋转调强放疗(volume modulated arc therapy,VMAT)和螺旋断层放疗(helical tomotherapy,HT)技术的子宫颈癌行双侧卵巢功能保留的放疗方法研究。方法搜集行子宫颈癌根治术及双侧卵巢移位术并实施放疗的ⅠA~ⅡB期10例年轻子宫颈癌患者资料。在已有的计划靶区体积(planning target volume,PTV)基础上分别进行降低卵巢受照剂量的IMRT、VMAT和HT计划设计,处方剂量45 Gy/25 F。比较PTV、卵巢、膀胱、直肠、肠袋、脊髓、骨髓和股骨头的剂量参数。进一步比较保留单侧卵巢计划在剂量学上的优势,并将其与三维适形放疗(three dimensional conformal radiation therapy,3D-CRT)技术在保留双侧卵巢功能的应用方面进行比较。结果PTV为(1065.02±145.33)cm3,左右卵巢体积为(13.12±6.52)cm3和(13.52±6.04)cm3,左右卵巢距PTV边缘最近距离为(3.40±1.23)cm和(3.70±0.83)cm,左右卵巢下缘距髂嵴最近距离为(-0.87±2.21)cm和(1.11±2.41)cm。与IMRT和VMAT比较,HT可降低左右卵巢的最大剂量[(3.84.±0.69)Gy和(3.10±0.66)Gy]和平均剂量[(2.47±0.51)Gy和(1.97±0.52)Gy],且在PTV的最大剂量[(49.01±0.92)Gy]、均匀性指数(0.092±0.028)、膀胱V20(89.22%~100%)、膀胱V30(43.35%~100%)、膀胱V40(19.59%~69.54%)、肠袋V40(13.06%~35.64%)、骨髓V20(46.1%~63.1%)和脊髓最大剂量(31.05~39.05Gy)方面,差异均具有统计学意义(均P<0.05)。IMRT在PTV最小剂量[(43.74±0.30)Gy]限制上具有优势(P<0.05),其他剂量学参数次于HT优于VMAT。保留单侧卵巢并没有实现更好地降低卵巢剂量和优化PTV和危及器官剂量分布的目的。3D-CRT在控制卵巢剂量和靶区适形指数方面不如IMRT、VMAT和HT(均P<0.05),受限于脊髓耐受剂量,该方法仅适用于靶区上缘低于第5腰椎的病例。结论HT与IMRT、VMAT和3D-CRT比较,可降低卵巢的最大剂量和平均剂量,并保证PTV和其他危及器官有较好的剂量Objective To explore the radiotherapy methods of preserving bilateral ovarian function for cervical cancer based on linear accelerator intensity modulated radiation therapy(IMRT),volume modulated arc therapy(VMAT)and helical tomotherapy(HT).Methods Ten young cervical cancer patients in stageⅠA-ⅡB with radical bilateral ovarian transposition and radiotherapy were enrolled in this study.Based on the existing planning target volume(PTV),the IMRT,VMAT and HT were designed to reduce the dose of ovarian radiation,and the prescription dose was 45 Gy at 1.8 Gy per fraction.The dose parameters of PTV,ovary,bladder,rectum,intestinal pouch,spinal cord,bone marrow,and femoral head were compared.The dosimetric advantages of preserving unilateral ovarian plans were investigated,and the three dimensional conformal radiation therapy(3D-CRT)technology was applied to preserve bilateral ovarian function.Results The volumes of PTV and left and right ovaries were(1065.02±145.33)cm3,(13.12±6.52)cm3,and(13.52±6.04)cm3,and the distance of left and right ovaries to the PTV edge and the closest distance between the left and right ovary lower margins were(3.40±1.23)cm,(3.70±0.83)cm,(-0.87±2.21)cm,and(1.11±2.41)cm,respectively.Compared with IMRT and VMAT,HT reduced the maximum dose[(3.84±0.69)Gy,(3.10±0.66)Gy],and the average dose[(2.47±0.51)Gy,(1.97±0.52)Gy]of the left and right ovaries.In addition,there were statistically significant differences in the maximum dose of PTV[(49.01±0.92)Gy],homogeneity index(0.092±0.028),bladder V20(89.22%~100%),V30(43.35%~100%)and V40(19.59%~69.54%),intestinal pouch V40(13.06%~35.64%),bone marrow V20(46.1%~63.1%),and maximum dose of spinal cord(31.05~39.05 Gy,all P<0.05).IMRT had an advantage in limiting the minimum dose of PTV at(43.74±0.30)Gy,and other dosimetric parameters were worse than HT,but better than VMAT(all P<0.05).The preservation of the unilateral ovaries did not achieve the goal of better reducing the ovarian dose and optimize the distribution of PTV and organs at risk.3D-CR

关 键 词：宫颈肿瘤/放射疗法 放射疗法/方法 卵巢/外科学 放射治疗剂量 

分 类 号：R737.33[医药卫生—肿瘤] R730.55[医药卫生—临床医学]