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.
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.
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.
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.
Clinical trial identification
All authors have declared no conflicts of interest.