High-dose-rate brachytherapy at 3 Gy per fraction for lip carcinoma: Treatment outcomes and toxicity at 5-years.

PURPOSE: Low-dose-rate brachytherapy (LDR-BT) is a well-established treatment for lip cancer. High-dose-rate (HDR)-BT is a promising alternative to LDR-BT, but data are limited. In this context, we retrospectively evaluated treatment outcomes in a series of patients who underwent HDR-BT for lip carcinoma between 2003 and 2021. MATERIALS AND METHODS: A total of 32 patients were included in this study, with a median age of 73.5 years (range, 61 - 88). The indications for HDR-BT were as follows: primary treatment (n = 17), adjuvant treatment (n = 3), and recurrent disease after surgery (n = 12). The prescribed dose was 18 fractions of 3 Gy administered twice daily. RESULTS: At a median followup of 45 months (range, 12 -232), the 5-year local recurrence-free interval was 96.9% (95% CI: 90.9-100%), the disease-free interval was 85% (95% CI: 70.9-99.1), and 5-year overall survival was 64.7% (95% CI: 44.7-84.8). Eleven patients died, all on age related comorbidities. Acute toxicity manifested as G1 dry desquamation in 6 patients (18.8%), G2 erythema in 10 patients (31.2%) and G3 confluent moist desquamation in 16 patients (50%). Late complications included G1 fibrosis (100% of cases). G1 and G2 depigmentation was observed in 8 (25%) and 6 (18%) patients, G1 telangiectasia occurred in 5 patients (16%). CONCLUSIONS: These data support the use of HDR-BT for lip cancer. The dose and fractionation schedule used in this study (18 fractions x 3 Gy twice daily) seems to be effective and safe.