Interstitial thermoradiotherapy for locally advanced and recurrent neoplasms of the head and neck

We describe the treatment of 22 consecutive patients with locally advanced (41%) or recurrent tumors (59%) in the head and neck (13 oral cavity and oropharyngeal, six cervical lymph nodes, two parotid recurrences, and one maxillary sinus recurrence) using a novel approach combining interstitial radiotherapy and ferromagnetic seed-induced hyperthermia. The complete and partial response rates were 68% and 27%, respectively, while 5% had no response. Response rates correlated inversely with tumor volume (P = .05). Median survival was 11 months with a two-year survival of 18%. The two-year actuarial local control was 38%. Continuous thermometry documented the time- averaged mean temperature achieved in all treatments to be 40.3°C. Toxicity was limited, with only 9% experiencing grade 3 toxicity (there was no grade 4 toxicity observed). Despite the modest thermal doses achieved in this study, our response rates are comparable with other interstitial radiotherapy techniques in a patient population with a poor prognosis. We are currently formulating more efficient seed materials to improve temperature homogeneity and effectiveness of heating.