摘要
目的我国是宫颈癌的高发地区,放疗是治疗宫颈癌的主要治疗方式之一。本研究旨在分析宫颈癌术后患者,采用逆向调强放疗技术(intensity modulated radiotherapy,IMRT)和旋转容积调强技术(volumetric modulated arc therapy,VMAT)放疗的剂量学分布特征。方法分析四川省肿瘤医院2014-05-01-2015-10-31接受宫颈癌术后辅助放疗的43例患者临床资料,在同一套CT图像上设计共面七野均分IMRT和共面二弧VMAT计划,处方剂量均为45Gy/25次,危及器官限量参考临床要求,并基于MATLAB平台编程获取计划统计结果,在靶区95%的体积达到处方剂量的条件下,分析比较两种计划的靶区相关参数、危及器官剂量分布、机器跳数和治疗时间等。结果 VMAT技术对危及器官的保护差异较大,小肠V_(30)和V_(20)、膀胱V_(40)、股骨头V_(20)和V_(30)、骨盆V_(20)和V_(30)、马尾D_(max)均优于IMRT计划(P<0.05),所有器官的D_(max)和D_(mean)(除直肠偏高外)也均有不同程度的降低,P<0.05;VMAT计划体内>15Gy左右剂量覆盖的体积较小,<15Gy左右剂量覆盖的体积较大,P<0.05。两种治疗计划对整个骨盆受照射剂量分布影响最大的是髂骨和髋骨,骶骨的平均剂量D_(mean)均高于髂骨和髋骨,P<0.05。VMAT技术放疗的机器平均跳数(558±8)MU和平均治疗时间(2.6±0.3)min明显偏少,平均分别减小了71%和73%,P<0.05。结论宫颈癌术后患者采用IMRT和VMAT两种治疗计划,靶区均能获得较满意的剂量分布,但VMAT计划对特定危及器官的保护更好,靶区适形度和均匀度更佳,且放疗机器跳数和治疗时间明显降低。从剂量学角度分析,VMAT技术更具优势。
OBJECTIVE The incidence of cervical cancer is high in China.Radiotherapy is one of the three major means of treatment of cervical cancer.The papper aimed to discuss the dose distribution characteristics of the postoperative cervical cancer patients treated with static intensity-modulated radiotherapy（IMRT）and rotary volumetric intensitymodulated radiotherapy（VMAT）.METHODS Retrospective analysis of 43 patients between 2015-10-31 and 2014-05-01 in Sichuan Cancer Hospital was done.All the patients received adjuvant radiotherapy after surgery for cervical cancer.A fixed-seven-field IMRT and a dual-arc VMAT scheme were designed on the same set of CT images.The prescription dose was 45Gy/25 F,and the plan statistical result based on the MATLAB platform programming.The dose of the organ,the number of monitor unit and treatment time were compared.RESULTS Small intestinal V_（30）,V_（20）,Bladder V_（40）,Femoral head V_（20）,V_（30）,Pelvic V_（20）,V_（30）,Horsetail D_（max）were significantly better in VMAT group than those of the IMRT group（P〈0.05）.For the pelvis,the average dose of the sacrum was higher than that of the ilium and hip bone（P〈0.05）.The parameter of dual-arc VMAT including the number of monitor（558±8）MU and treatment time（2.6±0.3）min was significantly better than that of fixed-field IMRT（P〈0.05）.CONCLUSIONS For patients with cervical cancer after surgery,all of the two kinds can bring a satisfactory conclusion.However,the target dose falling gradient,conformal index and homogeneity index of VMAT plan are better.The treatment time is significantly shortened.From the perspective of dosimetric analysis,VMAT technology has obvious advantages.
出处
《中华肿瘤防治杂志》
CAS
北大核心
2017年第10期708-713,共6页
Chinese Journal of Cancer Prevention and Treatment
关键词
宫颈癌
放射治疗
IMRT
VMAT
剂量学
cervical cancer
radiotherapy
intensity modulated radiotherapy
volumetric modulated arc therapy
dosimetry
