Long-term local control and survival after concomitant boost accelerated radiotherapy for locally advanced cervix cancer

Between 1989 and 1994, a prospective clinical trial tested the safety and efficacy of concomitant boost accelerated superfractionated (CBASF) radiotherapy for patients with locally advanced cervix cancer. CBASF radiotherapy included 45 Gy/25 fractions to the pelvis and a 14.4 Gy/9 fraction concomitant boost to the primary tumor, followed by brachytherapy for a total point A dose of 85 Gy to 90 Gy. The 22 patients of International Federation of Gynecology and Obstetrics stages IIIA-IVA who received CBASF radiotherapy now have a median follow-up time of more than 8 years. The 7-year actuarial rates of local control and overall survival are 81% and 36%, respectively. Serious late toxicity included bowel injury requiring colostomy in eight patients within 2.5 years after treatment, but no other severe toxicity was observed after longer follow-up intervals. The local control and survival rates achieved with CBASF radiotherapy were higher than those observed within a matched contemporaneous cohort of patients treated with standard radiotherapy alone at the same institution (p = 0.1 for local control, 0.09 for survival). The encouraging trend toward improved tumor control, tempered by the complication rate, suggests an opportunity to apply more sophisticated radiotherapy techniques that might sustain the favorable effects of dose intensification while mitigating the normal tissue toxicity.