PHASE-III TRIAL OF HIGH AND LOW-DOSE RATE INTERSTITIAL RADIOTHERAPY FOR EARLY ORAL TONGUE CANCER

Purpose: Oral tongue carcinomas are highly curable with radiotherapy, In the past, patients with tongue carcinoma have usually been treated with low dose rate (LDR) interstitial radiation, This Phase III study was designed to compare the treatment results obtained with LDR with t hose obtained with high dose rate (HDR) interstitial radiotherapy for tongue carcinoma, Methods and Materials: The criteria for patient sele ction for the Phase III study were: (a) presence of a T1T2N0 tumor tha t could be treated with single-plane implantation, (b) localization of tumor at the lateral tongue border, (c) tumor thickness of 10 mm or l ess, (d) performance status between 0 and 3, and (e) absence of any se vere concurrent disease, From April 1992 through December 1993, 15 pat ients in the LDR group (70 Gy/4 to 9 days) and 14 patients in the HDR group (60 Gy/10 fractions/6 days) were accrued, The time interval betw een two fractions of the HDR brachytherapy was more than 6 h, Results: Local recurrence occurred in two patients treated with LDR brachyther apy but in none of the patients treated with HDR. One- and 2-year loca l control rates for patients in the LDR group were both 86%, compared with 100% in the HDR group (p = 0.157), There were four patients with nodal metastasis in the LDR group and three in the HDR group, Local re currence occurred in two of the four patients with nodal metastases in the LDR group, One- and 2-year nodal control rates for patients in th e LDR group are were 85%, compared with 79% in the HDR group, Conclusi on: HDR fractionated interstitial brachytherapy can be an alternative to traditional LDR brachytherapy for early tongue cancer and eliminate the radiation exposure for medical staffs. Copyright (C) 1996 Elsevie r Science Inc.