Brachytherapy for lower lip epidermoid cancer: tumoral and treatment factors influencing recurrences and complications.

From 1972 to 1991, 237 patients with squamous cell carcinoma of the lower lip were treated by exclusive LDR brachytherapy (192Ir). There were 158 T1, 61 T2, 17 T3 and 1 T4 with 231 N0, 3 N1 and 3 N2 patients. The actuarial values at 5 years for local and regional controls, overall and specific survivals were 95%, 91%, 74% and 91%. Salvage treatment increased local control up to 99% and regional control to 94%. No heterolabial recurrence has been observed since the entire lip is treated, even for small tumors. The regional control depends closely on the thickness of the labial tumor (> or = 1 cm, p < 0.0001). The healing of treatment-induced mucositis is sometimes delayed for thick tumors (> or = 1 cm, p = 0.015). Late complications are not related to tumoral thickness but to the treated thickness (> 1.4 cm, p = 0.018) and particularly to the thickness of normal tissue included in the 85% isodose (treated thickness - tumoral thickness > 0.4 cm, p = 0.025). The use of a leaded protection and low linear radioactivity wires (< 2 mCi/cm, < 8.6 muGy/h.m2/cm) especially for large target volumes is required to lessen late complications. Based on this review, we advocate exclusive brachytherapy for small and intermediate tumors, with elective bilateral submaxillary and submental dissection for thick, high grade or commissure tumors. Simple recommendations are made to assure quality of the brachytherapy treatment.