RADIOTHERAPY OF STAGE-I AND STAGE-II CARCINOMAS OF THE MOBILE TONGUE AND OR FLOOR OF THE MOUTH/

From 1977 to 1990, 94 evaluable patients were treated with iridium-192 implantation in the Centre Claudius Regaud for a Stage I (52 patients ) or a Stage II (42 patients) squamous cell carcinoma of the mobile to ngue and/or the floor of the mouth. Interstitial brachytherapy was ass ociated with external irradiation in 68 patients (group 1; mean dose, 48 Gy for external irradiation, 26 Gy for brachytherapy) or was exclus ive in 26 patients (group 2; mean dose, 66 Gy). The mean follow-up was 44 months. Eleven acute complications were noted during or immediatel y after the implant (1 lethal myocardial infarction, 6 hematomas of th e tongue which spontaneously resolved, 3 local sepsis). The mean durat ion of the mucositis was 9 weeks (from 4 to 20 weeks). Ten patients (1 7%) experienced a late complication (8 in group 1, 2 in group 2): 3 bo ne necroses requiring hemimandibulectomy (1 post-operative death), 1 t ongue necrosis treated by a transoral mucosal excision, 6 bone exposit ions which recovered after medical treatment. Local control rates for T1 and T2 tumors were 75% (39/52) and 51% (21/41), respectively. Sixte en patients (17%) presented a nodal relapse which was associated in 6 cases with a concomitant local relapse. The local control rate of T1 t umors was 64% (23/36) in group 1 versus 100% (16/16) in group 2 (p < 0 .01). For T2 tumors, these figures were 45% (14/31) and 70% (7/10), re spectively (p > 0.3). The influence of 13 parameters on the local cont rol was studied in analysis. In the one model analysis, a cox regressi on tumor size was significantly predictive of actuarial local recurren ce (p < 0.001). The therapeutic modality was close to the significance level (p = 0.06). The other variables (age, sex, anatomic site, macro scopic aspect of the tumor, pathologic differentiation, technique of i mplant, intersource spacing and dose rate) had no significant influenc e. This retrospective study suggests that exclusive brachytherapy is t he best modality in terms of local control and functional results.