Pulse dose-rate brachytherapy and treatment of uterine cervix cancer: impact of a 3D or a 2D dosimetric support

摘要

PURPOSE: To evaluate two dosimetric supports used in pulse dose rate brachytherapy (PDR): coverage of target volumes, dose to organs at risk, residual tumor after surgery, survival. PATIENTS AND METHODS: Twenty patients treated for uterine cervix tumor first by brachytherapy PDR had a dosimetric CT-scan after implantation. For 9 patients, the treatment was planned from standard radiographies and then reported on CT-scan images. For 11 patients, it was directly planned from CT-scan. Six weeks after, 18 patients underwent surgery. RESULTS: With a median follow-up of 22 months, 2 year actuarial survival was 89%. Six patients developed grade II urinary or gynecological complications (LENT SOMA scale). No residual tumor was found for 12 patients (7 with a 3D treatment and 5 a 2 D treatment). Ninety-five percent of CTVHR received 53 Gy (2D treatment) or 63 Gy (3D treatment). Two cm3 of bladder wall received 63 Gy (2D) or 74 Gy (3D) although 2 cm3 of rectal wall received 37 Gy (2D) and 35 Gy (3D). CONCLUSION:Using CT-scan made us improve the coverage of the uterine cervix but increase the dose received by the bladder, without increasing the rate of histological remission after surgery. We should be prudent before changing our practice.