Relation between 201Tl to 67Ga uptake ratio and histological type in primary lung cancer.

Quantitative 201Tl and 67Ga scans were performed on 44 patients with primary lung cancer to ascertain the differences in 201Tl and 67Ga uptake by tumors; especially the crude uptake ratio (CUR) of 201Tl to 67Ga was evaluated in relation to histological type. Adenocarcinomas showed a CUR of 2.00 +/- 1.55, the greatest value among all histological types. Epidermoid carcinomas and oat cell carcinomas had CURs of 0.47 +/- 0.30 and 0.37 +/- 0.05, respectively, both showing significantly lower values than adenocarcinomas (P less than 0.01). On the other hand, adenosquamous carcinomas indicated a CUR of 0.91 +/- 0.15, an intermediate value between adenocarcinomas and epidermoid carcinomas (P less than 0.05). These results indicated that 201Tl and 67Ga uptake by lung cancer was closely correlated with histological type, and also suggested that 201Tl and 67Ga scans enabled various histogeneses of lung cancer to be visualized.