IPSA联合宫颈中心加量在局部晚期宫颈癌腔内联合组织间插植治疗中的应用

Application IPSA combined with increasing cervical center dose in intracavitary and interstitial brachytherapy for locally advanced cervical cancer

目的分析IPSA联合宫颈中心加量方式在局部晚期宫颈癌腔内联合组织间插植(IC/IS)治疗中剂量学方面优势。方法选取宫颈癌(ⅡB期)经调强放疗45 Gy分25次后局部病灶≥5 cm患者46例,行宫腔管及插植针植入,在CT图像上勾画高危临床靶体积(HR-CTV)、直肠、膀胱、乙状结肠及宫颈加量区宫颈中心(HR-宫颈),采用IPSA优化。根据宫颈中心是否加量,分成IC/IS+宫颈中心(HR-宫颈)组(A组)和IC/IS组(B组),比较A、B组间剂量学差异。结果A组宫腔管驻留时间较B组明显提高(P<0.001);宫颈中心的V150%和V200%由原来B组63.94%和30.80%分别提高到91.54%和64.06%;A组D_(90%)及D100%低于B组(P<0.05);危及器官受量相近(P>0.05)。结论IPSA联合宫颈中心加量方式可满足高危临床靶体积D_(90%)受量及危及器官限量,并可提高宫颈中心区剂量。

Objective To analyze the advantages of IPSA combined with increasing cervical center dose in intracavitary and interstitial brachytherapy(IC/IS)for locally advanced cervical cancer.Methods A total of 46 stageⅡB cervical cancer patients with,local lesion size≥5 cm after 45 Gy/25f external intensity-modulated radiotherapy(IMRT)were recruited.Uterine tandem and needles were implanted,CT was performed,and then HR-CTV,rectum,bladder,sigmoid colon and the area of cervix increased dose(HR-cervix)were delineated,IPSA was used for optimization.According to whether the dose of HR-cervix was increased or not,all patients were divided into IC/IS+HR-cervix group(group A)and IC/IS group(group B).The differences in dosimetric parameters were compared between two groups.Results The relative uterine tandem dwell time was significantly extended in group A(P<0.001).In group B,the V150%and V200%volumes of HR-cervix were increased from 63.94%and 30.80%to 91.54%and 64.06%.The D_(90%)and D100%in group A were significantly lower than those in group B(both P<0.05).There was no statistical difference in organ at risk(OAR)dose.Conclusion IPSA combined with increasing cervical center dose can meet the HR-CTV D_(90%)dose requirement,normal tissue dose limits,and can escalate the doses to local areas of the cervix.