RESULTS OF 137CS NEEDLE INTERSTITIAL IMPLANTS FOR CARCINOMA OF THE TONGUE

Sixty-one patients with squamous cell carcinoma of the tongue received 137Cs implants at Tokai University Hospital from 1978 through 1987. In 53 cases, the neck regions including the primary lesions were treated with external irradiation at doses of 5.1-54.1Gy. Total dose to the primary lesion was 50-120Gy. Twenty patients also received chemotherapy. Relapse-free local control at 2 years was 47/61 (77%). Thelocal control rate was similar at various T stages: T1, 13/15 (87%); T2, 28/38 (74%); T3+4, 6/8 (75%). External irradiation had no significant effect on local control. Prophylactic external irradiation of over 30Gy clearly prevented the development of neck node metastases; 1/11 (9%) compared to 15/37 (41%) for doses under 30Gy. However, there was no significant difference in the 2-year survival rate (82% compared to 92%). Chemotherapy had no significant effect on control of the primary tumor nor on prevention of neck node metastases in T2 patients. The overall 5-year survival rate was 73%, and by stage: T1, 79%, T2, 79%; T3+4, 42%; N_, 76%; N+, 63%, stage I, 85%; stage II, 79%; stage III+IV 42%. Two cases of osteonecrosis were found in the minimum 2-year follow-up group. We conclude that the combination of 137Cs needle implants and external irradiation over 30Gy is excellent treatment protocol for carcinoma of the tongue.