Excellent functional outcome in patients with squamous cell carcinoma of the base of tongue treated with external irradiation and interstitial iodine 125 boost.

Background: Local control, functional outcome, and complications in patients with carcinoma of the base of tongue (BOT) were analyzed to assess the impact of interstitial implant boost with I-125 seeds.

Methods: Between December 1986 and May 1995, 16 patients with squamous cell carcinoma of the BOT received treatment at the William Beaumont Hospital and 4 received treatment at the Northern Virginia Cancer Center. The primary tumor classification for this group consisted of T1/T2-11 patients, T3/T4-9 patients. All patients initially received 50.4-66.6 Gray (Gy) (median: 54 Gy) external beam irradiation to the primary site and regional lymph nodes followed by an interstitial implant boost 2 to 3 weeks later. Implant dose ranged from 20 to 32 Gy (median: 27 Gy). The implanted volume included the tumor and glossotonsillar sulcus in all patients and the pharyngeal wall or tonsil in select cases.

Results: Median follow-up was 47 months (range, 6-88 mos). Two patients have failed within the tumor bed (T2 and T4) for a 5-year actuarial local control rate of 88%. The T2 patient was salvaged surgically, for an overall 5-year actuarial local control rate of 93%. No patients have relapsed within the neck as the only or first site of failure. The 5-year actuarial overall survival rate was 72%. Complications included three cases of exposed bone and one case of cranial nerve XII palsy. All complications were managed conservatively. Excellent to good functional outcome, including speech and swallowing, was preserved in 18 of the 20 patients.

Conclusions: Patients with cancer of the BOT can be treated effectively with an interstitial boost utilizing I-125 seeds. Overall, local control is excellent and complications are minimal. Of greatest significance, organ preservation with excellent understandability of speech and diet tolerance was achieved in 90% of the patients.