Hypofractionation vs. conventional radiotherapy fractionation in the conservative treatment of T1 glottic cancer: a prospective cohort study.

Abstract

Definitive radiotherapy is an effective single-modality in T1 glottic cancer. Hypofractionated schemes could offer excellent results in a shorter treatment period. We aimed to evaluate the clinical outcomes and toxicity comparing conventional vs. hypofractionated radiotherapy treatment in T1N0M0-glottic cancer. Between Jan-1st, 2005 and August-1st, 2017, in a prospective cohort study, with 10-year follow-up, 138 patients were treated with conventional schedule 2 Gy/day, total dose 70 Gy/7 weeks (N=71) or hypofractionated schedule 2, 2-2, 25 Gy/day, total dose 63, 8-63 Gy/5, 5 weeks (N=67). Endpoints were clinical-response rate, local relapse-free survival (LRFS), laryngectomy-free survival (LFS), toxicity rates, relapse-free survival (RFS), metastasis-free survival (MFS), second tumour-free survival (2TFS), and overall survival (OS). All patients showed a complete clinical response. No differences were found for LRFS (p=0.869), LFS (p=0.975), RFS (p=0.767), MFS (p=0.601), 2TFS (p=0.293), or OS (p=0.685). Acute toxicity for skin and mucosae was similar (p=0.550 and p=0.698). Acute laryngeal toxicity was higher in the hypofractionation group (p=0.004), due to an increase in slight moderate grade. No differences in late laryngeal edema were found (p=0.989). Radiotherapy offers high rate survival, local control, and larynx preservation after 5-10-year follow-up. A hypofractionation could be preferable, since it offers the same results as conventional with fewer treatment sessions.