1.Evaluation of clinical efficacy and safety of single-channel intracavitary applicator for uterine cervical cancer: 3-year long-term results of a prospective randomized phase Ⅱ clinical trial
Dan LI ; Rong HUANG ; En WEN ; Zhouxue WU ; Sheng LIN ; Lijia HE ; Peirong REN ; Changling SHANG ; Li XIANG ; Hongru YANG ; Jingbo WU
Chinese Journal of Radiation Oncology 2021;30(11):1154-1158
Objective:To evaluate the 3-year survival outcomes and late injury between the self-designed patent single-channel applicator, which was modified from the traditional tandem applicator and wrapped with a oval-shield alloy around the source channel and standard Fletcher-type applicator in the high-dose-rate brachytherapy for cervical cancer.Methods:Patients initially diagnosed with cervical cancer in the Affiliated Hospital of Southwest Medical University from December 2011 to April 2017 were enrolled and randomly assigned into the external beam radiotherapy (EBRT)+ single-channel intracavitary applicator group (the patent single-channel group) and EBRT+ the Fletcher applicator group. The whole pelvis irradiation was delivered with 6-MV photons via a four-field box variant or anterior and posterior parallel fields. Five to six fractions of intracavitary brachytherapy were performed at a dose of 7 Gy at point A once a week after 30 Gy (Equivalent Dose in 2 Gy at point A: 80-90 Gy). Chemotherapy was given with intravenous injection of cisplatin at a dose of 40 mg/m 2 once weekly during EBRT. Clinical efficacy and safety were evaluated after corresponding treatment. Results:In total, 150 eligible cases were assigned into the Fletcher applicator group and 149 cases into the patent single-channel group. Up to December 2020, all patients had been followed up for 3 years, and the median duration of follow-up was 61 months. In the Fletcher group, the 3-year overall survival, progression-free survival and locoregional failure-free survival was 76.3%, 78.1% and 75.4%, and 83.8%, 80.3% and 85.5% in the single-channel group, respectively. In the Fletcher group, the cumulative rate of grade 3-4 late rectal complications was 3.3% and 6.7% in the single-channel group ( P=0.122). The cumulative rate of grade 3-4 bladder complications was 1.3% in the Fletcher group and 0.7% in the single-channel group ( P=1.000). Conclusion:The self-designed patent single-channel intracavitary applicator yields equivalent long-term clinical efficacy and safety to the standard Fletcher-type three-channel applicator in the HDR brachytherapy for uterine cervical cancer.