USEFULNESS OF 67Ga SCINTIGRAPHY IN LUNG CANCER

Gallium-67 citrate scintigraphy (67Ga scintigraphy) was evaluated in 305 patients with lung cancer. The positive rate among 135 patients, in whon the radiation doses were less than 10Gy when 67Ga scintigraphies were performed, was 76% ; positive rates for small cell carcinomas, poorly differentiated epidermoid carcinomas and large cell carcinomas were higher (>90%), while positive rate for well differentiated adenocarcinomas was the lowest (57%).The positive rates for poorly differentiated types of epidermoid carcinomas and adenocarcinomas were higher than those of well differentiated types. No relation between 67Ga accumulation and tumor diameter was recognized within the range of tumor diameter from 30 mm to 100mm. In small cell carcinomas and well differentiated adenocarcinomas, the cases that showed high 67Ga accumulation tended to decrease according to increase of radiation dose. But there were many cases that showed high 67Ga accumulation when radiation dose increased in other histologic types. In 86% of cases with atelectasis or pleural effusion or inflammatory change, 67Ga scintigraphy was useful for differentiating the extent of tumor from these changes. 67Ga scintigraphy appeared to assist the differential diagnosis of histologic types of lung cancer, and to be useful for evaluation of the extent of tumor.