ROLE OF INTERSTITIAL BRACHYTHERAPY IN ORAL AND OROPHARYNGEAL CARCINOMA - REFLECTION OF A SERIES OF 1344 PATIENTS TREATED AT THE TIME OF INITIAL PRESENTATION

Our study focuses on a series of 1344 cases of carcinoma of the oral c avity and oropharynx treated between 1973 and 1992. Brachytherapy was always performed with iridium 192, either alone or in combination with external-beam irradiation or with surgery for the treatment of the pr imary tumor. For the oral cavity, we studied 565 cases of mobile tongu e, The local control and overall survival rates, respectively, at 5 ye ars are as follows: for T1, 92% and 70%; for T2, 62% and 42%; and for T3, 50% and 29%. For the subgroup T1T2N0, there was a better prognosis for treatment by brachytherapy of the primary lesion alone (p < 0.000 1), Two hundred seven cases of floor-of-mouth carcinoma have been repo rted, The T3T4 patients were not considered surgical candidates. The l ocal control and overall survival rates, respectively, at 5 years are as follows: for T1, 97% and 71%; for T2, 72% and 42%; and for T3, 51% and 35%, Ninety-seven patients were treated by postoperative brachythe rapy, These were patients for whom the margins after surgery were posi tive or narrow, A technique termed the modified bridge is described fo r lesions located in the mandible, Carcinomas of the buccal mucosa are rare in our country; only 42 cases were treated in this comparison of two techniques, and the overall survival rate was 48%, Epidermoid car cinomas of the oropharynx have nearly always been treated by a combina tion of external-beam irradiation and brachytherapy because of the bil ateral node risk, Seventy-two patients with epidermoid cancers of the base of the tongue had an overall survival rate of 44%, The tonsil, so ft palate, and pillars benefited from the use of the loop technique of brachytherapy combined with external-beam irradiation, Three hundred sixty-one patients were treated, Among these patients were two groups with different prognoses, Patients with tonsil, soft palate, and poste rior pillar carcinomas had a local control rate of 84% and an overall survival rate of 57%, Conversely, the anterior pillar and the pharyngo glossal sulcus have a local control rate of only 65% and an overall su rvival rate of 38%. Statistical analysis revealed the prognostic facto rs for local control. The complications were classified into four grad es: minor (20%), moderate (9%), major (4%), or inducing death (0.2%), The bone complications of grade 2 or 3 are more frequent for the floor of the mouth than for other locations.