276P Once-weekly high dose rate interstitial brachytherapy for carcinoma cervix is convenient, effective & well-tolerated

Abstract

Aim/Background: Interstitial brachytherapy (ISBT) in cervical cancer is used for post-operative gross residual disease and unoperated cases with poor anatomy/or bulky disease precluding intracavitary insertion. There is no standard dose fractionation schedule for ISBT. This study describes a logistically convenient schedule. Methods: The study included 35 patients of advanced non-metastatic carcinoma cervix (squamous cell carcinoma & adenocarcinoma), 24 with bulky primary disease and 11 with vault recurrence/ residual, treated between June 2012 and December 2014. All patients underwent pelvic external beam radiotherapy (EBRT) using standard 4-field technique to a dose of 50Gy/25#/ 5 weeks; para-aortic nodes were treated if involved; concurrent chemotherapy was used wherever appropriate. Thereafter, the patients underwent 2 insertions of high dose rate (HDR) ISBT using the Syed-Neblett perineal template with titanium needles inserted percutaneously under spinal anaesthesia; ISBT was done once weekly as a daycare procedure; all patients underwent computerized tomography (CT) planning on the Brachyvision treatment planning software using volume optimization to achieve standard combined (ie EBRT+ ISBT) dose-volume constraints for 2cc of urinary bladder (EQD2 75Gy) & rectum (EQD2 70Gy) [EQD2= equivalent dose delivered at 2Gy per fraction]; prescribed dose was 9Gy /# to the high-risk clinical target volume. Results: Thirty two patients (91.4%) achieved complete response and 3 achieved partial response. At a median follow-up of 20 months, 30 patients (85.7%) continue to be in remission. No patient had significant post-operative local pain/ bleeding; 4 patients had post-spinal headache persisting beyond 1 day; no patient had local skin/mucosal infection. There were 3 cases of grade 3 late rectal toxicity (8.57%) and none of grade 3 cystitis. Conclusions: Once weekly HDR ISBT for carcinoma cervix is well-tolerated, convenient and effective. The difficulties of continuously retaining the perineal template over several days of continuous therapy, including pain, discomfort and local infection are easily avoided by this protocol. Disclosure: All authors have declared no conflicts of interest.