A new classification of lung cancer from a nucleomedical viewpoint using quantitative 201Tl and 67Ga scans in relation to histological type

The possibility of nucleomedically classifying lung cancer was studied with quantitative 201Tl and 67Ga scans. Fundamental experiments with phantoms were performed to correct 201Tl and 67Ga uptake by tumors, and a clinical study based on these experiments was carried out on 31 patients with lung cancer. The classification of lung cancer was impossible by measuring either 201Tl uptake or 67Ga uptake alone, but was possible by calculating the Crude Uptake Ratio (CUR), the ratio of 201Tl uptake to 67Ga uptake by tumors on the same patients. Fifteen adenocarcinomas had a high CUR of 1.45 +- 0.77, many of them taking up more 201Tl than 67Ga. Nine epidermoid carcinomas had a CUR of 0.34 +- 0.25, significantly lower than adenocarcinomas (p<0.001), and they took up more 67Ga than 201Tl. Two adenosquamous carcinomas had a CUR of 0.95 +- 0.19, intermediate between adenocarcinomas and epidermoid carcinomas. CURs varied greatly ranging from 0.03 to 4.31 and the 31 patients showed a continuous arrangement from low-CUR epidermoid carcinoma to high-CUR adenocarcinoma. The measurement of 201Tl and 67Ga uptake by the tumors was found to enable not only the nucleomedical classification but the presumption of various histogeneses in lung cancer. (author)