Purpose: This study reports on T3/T4 base of tongue (BOT) tumors treated at the Erasmus MC (Rotterdam) with external beam radiotherapy (EBRT) and brachytherapy (BT). Local control, survival, and functional outcome are compared to results obtained in similar patients treated at the Vrije University Medical Center (VUMC, Amsterdam) by surgery and postoperative RT (PORT).
Methods and materials: At Rotterdam 46/2 Gy was given to the primary and bilateral neck, followed by an implant using low-dose-rate (LDR 24-35 Gy; median 27 Gy), or fractionated high-dose-rate (fr. HDR 20-28 Gy; median 24 Gy). A neck dissection (ND) was performed in case of N+ disease. 67% of BOT tumors had a T4 cancer. At Amsterdam surgery (S) followed by PORT 40-70 Gy (median 60 Gy) was performed; 26% BOT tumors were T4. Sex, age and nodal distribution were similar. Actuarial local control and survival were computed. Performance Status Scale (PSS) scores were established. Xerostomis was determined on visual analog scales (VAS).
Results: Local failure at 5-years was 37% (Rotterdam) vs. 9% (Amsterdam) (p < 0.01). The overall survival was not significantly different (median 2.5 years vs. 2.9 years, respectively [p = 0.47]). The PSS favored brachytherapy. Both groups were equally affected by xerostomia.
Conclusions: The 5-year local control was 65% with EBRT and BT. This result is strongly affected by 4 patients with residual disease after implantation. The Rotterdam patients had more advanced BOT tumors (67% vs. 26% T4), explaining the higher local failure rate. Given the organ preservation properties of radiotherapy-only and the better PSS scores, the jury is still out on the optimal treatment for BOT tumors.