Indications, techniques and results of postoperative brachytherapy in cancer of the oral cavity

Purpose/objective : We tried to reduce the number of local recurrences after surgery and external beam irradiation (EBI) in carcinoma of the oral cavity, when margins were positive or close. Material and methods : From 1980 to 1992, we treated 97 cases of carcinomas of the oral cavity by postoperative brachytherapy. Surgery was combined with EBI + brachytherapy in 51 cases and with brachytherapy alone in 46 cases. We treated 29 T1, 34 T2, 30 T3T4 and four Tx (73% were N0 at first examination and 23% had positive nodes). The type of surgery is analysed. Brachytherapy was performed in one or two planes along the surgical scar. If the mandibular rim was resected, especially when the tongue or the remaining floor were sutured to the internal face of the inferior lip or to the buccal mucosa, the bridge technique was used. To decrease the dose to the inferior part of the mandible, the bridge was modified thanks to experimental dosimetry. Results : At 5 years, the local control (LC) is 89%, the locoregional control (LRC) 82%, the specific survival (SS) 74% and the overall survival (OS) 67%. Complications : We noted 19% of grade 1 (minor), 12% of grade 2 (moderate) and 6% of grade 3 (major) complications. Conclusion : Compared with the results of the literature, we think that postoperative brachytherapy can improve classical radiosurgical results in selected cases with a risk of local recurrence.