Paired observation of californium-252 neutron intraluminal brachytherapy combined with external-beam radiotherapy with and without lead shielding for cervical cancer

Abstract

Objective To compare the efficacy between californium-252(252Cf)neutron intraluminal brachytherapy combined with external-beam radiotherapy with lead-shielding pelvic parallel opposing field technique and non-lead-shielding four-field box technique for cervical cancer. Methods A total of 52 patients with stage Ⅱa-Ⅲb cervical squamous cell carcinoma who were admitted to our hospital from 2004 to 2007 were enrolled as subjects and paired by clinical stage, age, tumor size, and degree of anemia. The 26 pairs of patients were divided into lead-shielding pelvic parallel opposing field group(lead-shielding group)and non-lead-shielding four-field box group(non-lead-shielding group). For all patients in both groups, 252Cf neutron brachytherapy was added in external-beam radiotherapy. The local control(LC), overall survival(OS), and disease-free survival(DFS)rates were calculated using the Kaplan-Meier method and analyzed using the log-rank test. The difference in the incidence of late complications was analyzed using the McNemar method. Results There were significant differences in 5-year LC, OS, and DFS rates between the lead-shielding group and the non-lead-shielding group(85% vs. 81%,P=0.014; 89% vs. 73%, P= 0.013; 89% vs. 73%, P= 0.013). There was also significant difference in the incidence of late complications between the lead-shielding group and the non-lead-shielding group(12% vs. 23%, P= 0. 008). Conclusions When intraluminal brachytherapy combined with external-beam radiotherapy is used to treat cervical cancer, the centers of the front and back fields should be shielded by lead, regardless of whether the parallel opposing field technique or the four-field box technique is used. Key words: Cervical neoplasms/radiotherapy; Radiotherapy, external beam radiation; Radiotherapy, 252Cf neutron; Lead shielding