妇科肿瘤后装逆向调强放射治疗的剂量学和疗效研究

Dosimetry and Efficacy Research on the Afterloading Brachytherapy Inverse Intensity-Modulated Radiotherapy of Gynecological Tumor

目的:探讨后装逆向调强放射治疗在妇科肿瘤治疗中的应用价值,为临床治疗的技术选择提供依据。方法:选取20例Ⅰ～Ⅲ期宫颈癌患者,随机分为A、B两组,各10例。Ⅰb期2例,Ⅱa期4例,Ⅱb期12例,Ⅲa期2例。病理分型:鳞癌16例,腺癌4例。以上诊断均经过病理学证实。平均年龄55.67岁(32岁～65岁)。A组病例行后装逆向调强放射治疗,采用Inverse Planning Simulated Annealing(IPSA)技术进行剂量优化设计,B组病例行三维适形后装放射治疗。A、B组患者均采用3根施源器,进行腔内照射并同步箱式四野等中心外照射,剂量为46 Gy/23次。依据曼彻斯特剂量学系统,给予A点(宫口上2 cm,宫腔中轴线左右旁开2 cm处为A点位置)处方剂量6 Gy/次,照射次数5次,2次/周。对比分析A、B两组患者的靶区剂量分布,危及器官(直肠、膀胱)受量,放射性并发症及近期疗效。结果:A组患者的靶区剂量适形度和均匀性均好于B组患者。患者0.5年～1.0年的肿瘤局部和区域控制率:A组患者分别为96%(95%CI,85%～99%)和95%(95%CI,81%～99%)。B组患者局分别为93%(95%CI,85%～99%)和92%(95%CI,81%～99%)。危及器官(直肠、膀胱)受量:A组患者的直肠、膀胱最大受量比B组患者小约35%。A组患者的直肠、膀胱75%处方剂量受照体积V75约只为B组患者的二分之一。放射性并发症:RTOG 1级反应:A组患者为1例,B组患者为6例。RTOG 2级反应:A组患者为0例,B组患者为3例。RTOG 3级反应:A组患者为0例,B组患者为1例。近期疗效:在A、B组患者放疗期间及治疗结束后,几乎所有患者的肿瘤均有不同程度的缩小,有效率(CR+PR)均为92%以上。结论:后装逆向调强放射治疗技术具有近期疗效明显,靶区剂量适形度、均匀性好,危及器官受量低,放射性并发症少等优点,值得在妇科肿瘤治疗中广泛应用。

Objective： To investigate the application value of the Afterloading Brachytherapy Inverse Intensity-Modulated Ra- diotherapy of Gynecological Tumor. Methods： 20 patients with cervical cancer, were randomly divided into A, B two groups, 10 cases in each. Stage I b 2 cases, stage Ⅱa 4 cases, stage Ⅱb 12 cases, stage Ⅲa 2 cases. Pathological types： Squamous Cell carcinoma 16 cases, Adenocarcinoma 4 cases. The average age was 55.67 years （32 years- 65 years old）. Group A patients re- ceived the Afterloading Brachytherapy Inverse Intensity-Modulated Radiotherapy. The dose optimization technology was the In- verse Planning Simulated Annealing （IPSA） .Group B patients received the Three-Dimensional Comformal Atlerloading Brachytherapy. Group A and B patients were treated with 3 applicator for intracavitary irradiation and synchronous box around 4 fields isocenter external irradiation, prescription dose 46 Gy/23F. According to the Manchester system ,the prescription dose of A points （2 cm above the cervix, 2 cm both in the left and right sides of the axis of uterine cavity ） was 30 Gy in 5 fi：actions, 2 times each week. Analysed groups A and B patients about the target volume dose distribution, organs at risk （rectum, bladder）, short-term curative effect and radioactive complications. Results： The dose conformal and homogeneity index of the target vol- ume of group A were better than group B. The 0.5 year~ 1.0 year tumor local and regional control rate ：group A patients were 96% （95% CI,85%-99%） and 95% （95% CI,81%-99%）, group A patients were 93% （95% CI,85%-99%）and 92% （95% CI, 81%-99%）.Organs at risk （rectum, bladder）： the maximum dose ~f rectum and bladder of group A patients were about 35% less than group B, The 75% prescription dose irradiated volume of rectum and bladder of group A patients were about only 1/2 ofgroup B. Radioactive complications：RTOG grade 1 reaction ： group A： lcase, group B： 6 cases. RTOG grade 2 reaction ： group A： 0 ease, group B： 3cases. RTOG grade 3 reaction ： group A： 0 case, group B： leases. Short-term efficacy ： the tumors size of group A and B patients had both reduced during and after the radiotherapy, efficiency （CR＋PR） was more than 92%. Conclu- sions： Afterloading Brachytherapy Inverse Intensity-Modulated Radiotherapy technique have obvious short-term efficacy, bet- ter dose conformal and homogeneity index of the target volume, lower dose of organs at risk, fewer radioactive complications. It＇s worthy of widely applicated in the gynecological cancer therapy.