Patients with locally advanced oral squamous cell carcinomas (T3-4N0-3M0) treated with RT or HT combined with RT (HRT) were analyzed retrospectively. The RT group consisted of 31 patients (M/F - 27/4), and the HRT group consisted of 32 patients (M/F - 29/3). RT was performed using conventional fractionation (2 Gy delivered 5 times/week) for a total dose of 54-60 Gy with a 2 week split course after delivery of 36-40 Gy. Regional HT was performed using a Supertherm EP40 (40.68 MHz) capacitive heating device (Moscow, Russia), for 60-70 min 3 times a week for a total of 8-10 times. Average tumor temperatures were 42.7±0.2°C. RT was performed within 10-15 min after the end of HT. Complete response (CR) of primary tumors was achieved in 20 patients (62.5%) treated with HRT, and in 11 patients treated with RT alone (35.5%) (p<0.05). There was a median time to recurrence of 36 months in the HRT group compared to 9 months in the RT group (p<0.01). At the same time, the use of HT was associated with an increased incidence of radiation-induced mucositis. Median survival time for overall survival was better for the HRT group (48.0 months vs. 26 months for the RT group) (p<0.05). In addition, employment of HT did not influence the frequency of distant metastases. From this aspect, disease-free survival was not statistically different between the two therapeutic approaches. This study demonstrates that regional HT confers a significant local control and long-term survival benefit with an acceptable toxicity risk in patients with advanced oral cancer who are receiving RT.
2009 Japanese Society for Thermal Medicine