Postoperative brachytherapy alone for T1-2 N0 squamous cell carcinomas of the oral tongue and floor of mouth with close or positive margins

Purpose: To evaluate the efficacy of postoperative brachytherapy alone (bra chy) for Stage T1-2 squamous cell carcinomas (SCC) of the floor of mouth (P M) and the oral tongue (OT) with close or positive margins. Methods and Materials: Between 1979 and 1993, 36 patients with T1-2 NO (24 T1, 12 T2) OT (19), and FOM (17) SCC with close or positive margins followi ng surgery underwent postoperative brachy. Mean patient age was 56 years (r ange 37-81) and sex ratio was 3.5:1 male:female. Mean surgery to brachy int erval was 36 days (range 16-68). The technique used was interstitial Iridiu m-192 (Ir-192) brachytherapy with plastic tubes and manual afterloading. Me an total dose was 60 Gy (range 50-67.4) at a mean dose rate of 0.64 Gy/h (r ange 0.32-0.94). Mean patient follow-up was 80 months. Results: The 5-year actuarial overall and cause-specific survivals of the e ntire group were 75% and 85%, respectively. The local control was 88.5% at 2 years, with a plateau apparent after 23 months. Of the 4 local relapses, 2 were salvaged with surgery and external beam radiotherapy (EBR). No tumor or treatment factors, including tumor size, margin status, disease site, o r radiation dose, were correlated with local control. The 2 head and neck s econd primaries underwent curative treatment on nonirradiated tissue. One p atient developed a grade 3 sequelae (bone and soft tissue necrosis). Grade 2-3 chronic sequelae were seen in 7 of 17 and 3 of 19 FOM and OT tumors, re spectively (p = 0.09). Conclusion: Postoperative brachy is a promising approach in T1-2 N0 OT and FOM SCC with close or positive margins. This approach is associated with hi gh rate of locoregional control and low risk of chronic sequelae, obviates major surgery, avoids potential sequelae of EBR (xerostomia, dysgueusia, fi brosis), and avoids treatment of second head and neck primary on nonirradia ted tissues. (C) 2000 Elsevier Science Inc.