Experiences in the treatment of tumour of base of the tongue with high dose rate interstitial radiotherapy on the basis of a retrospective analysis

PURPOSE: To describe the role, the execution and the importance of interstitial radiotherapy in the irradiation of the base of tongue cancer. MATERIAL AND METHODS: Between January, 1993 and December, 1998 nineteen patients with primary squamous cell cancer of the base of tongue (1 T1N0, 3 T2N0, 2 T3N0, 2 T3N2, 3 T4N0, 6 T4N1, 2 T4N2) were managed with brachytherapy partly with definitive intention combined with teletherapy (60-66 Gy) as a boost, partly as a single postoperative treatment. Irradiation was carried out by HDR after-loading (Ir-192) unit, using rigid needle or flexible plastic catheter. The treatment plan was made by PLATO 3D brachytherapy planning system. In case of boost the mean total dose of brachyherapy was 22 Gy (12-30 Gy), in postoperative treatment it was 27 Gy (24-30 Gy). RESULTS: 6-8 weeks after the definitive radiotherapy the CT/MR showed complete remission in 67% and partial remission in 33% of the patients. Of all treated patients during the mean follow-up period (30 months) the local tumour control was 42%. Five patients (26%) died in local failure. Six patients (32%) are alive with tumour. Osteoradionecrosis and fistula did not occur. CONCLUSIONS: In the oncological treatment of the advanced base of tongue tumour the combination of percutan and interstitial radiotherapy seems to be very advantageous,because it improves not only the curability, but the patients' quality of life as well.