Effectiveness of RF capacitive hyperthermia combined with radiotherapy for stages III and IV oro-hypopharyngeal cancers: a non-randomized comparison between thermoradiotherapy and radiotherapy.

Seventy-two patients with Stages III and IV (TNM, UICC, 1987) squamous-cell carcinoma of the oropharynx and hypopharynx (oro-hypopharyngeal cancer) were treated with external irradiation, or irradiation plus 13.56 MHz radiofrequency (RF) capacitive hyperthermia from 1989 to 1995. This study compared initial response, histological effect and 5-year survival rate of thermoradiotherapy (TRT) group with those of radiotherapy alone (RT) group. In the TRT group, 15 patients were treated definitively, and 18 patients preoperatively. In the RT group, 15 patients were treated definitively, and 24 patients preoperatively. With definitive irradiation, the complete response rate of the primary lesions was 73% in the TRT group and 27% in the RT group (p = 0.009) and the complete response rate of the metastatic lymph nodes was 80% in the TRT group and 27% in the RT group (p = 0.005). With preoperative irradiation, the pathological CR (No residual cancerous cells) rate of the primary lesions was 56% in the TRT group and 8% in the RT group (p = 0.01), and the pathological CR rate of the lymph nodes was 72% in the TRT group and 21% in the RT group (p = 0.001). The 5-year survival rates with definitive irradiation were 47.6% in the TRT group and 18.7% in the RT group (p = 0.025). Thus TRT was more effective than RT for advanced oro-hypopharyngeal cancer.