A preliminary and clinical study of radiation therapy for tongue carcinoma

Four hundred and seventy-four patients with squamous cell carcinomas of the tongue were treated with radiation therapy at the Department of Radiology, Osaka University Hospital between 1978 and 1987. Brachytherapy was mainly employed for the majority of the patients with T1 and T2 lesions, whereas the combination of external irradiation and brachytherapy was the treatment of choice for the patients with infiltrative T2 and more advanced lesions. Patients treated with brachytherapy alone were given an estimated tumor dose of about 70Gy within a week. Patients treated with the combined therapy received an estimated tumor dose of about 30Gy to 50Gy within 3 to 5 weeks from external irradiation, followed by 50Gy to 60Gy within a week from brachytherapy. The treatments used in this study improved the survival. The 2-year local control rates were 85% in T1, 77% in T2, 60% in T3 and 33% in T4 lesions. The 5-year actuarial survival rates according to the T stage were 78% in T1, 64% in T2, 50% in T3 and 40% in T4 lesions. One hundred and four patients(28%) of three hundred and sixty nine patients who had negative lymph nodes clinically had cervical lymph node metastases subsequently. Whereas twenty six patients(25%) of one hundred and five patients who had positive lymph nodes clinically proved to be false positive. The incidence of osteoradionecrosis was 6.0% in patients treated with the combination of external irradiation(30Gy) and brachytherapy(60Gy), while it was 1.7% in patients treated with brachtherapy alone(70Gy). Brachytherapy is a fairly good therapeutic technique for the majority of the patients with tongue cancers. The multicombined treatment modality could provide the chance for cure of advanced lesions.