Comparison of Gallium-67 Citrate and Technetium-99m Glucoheptonate in the Evaluation of Pulmonary Malignancies

Sixty-five patients with suspected or proven pulmonary malignancy were examined with (/sup 67/Ga)citrate and (/sup 99m/Tc)glucoheptonate ((/sup 99m/Tc)GH) scintigraphy. In the final diagnosis 39 had primary lung carcinoma, four metastases in lung, mediastinum, and pleura from carcinomas elsewhere, and 22 benign pulmonary diseases. The sensitivity in the detection of pulmonary malignancies was 91% with /sup 67/Ga and 95% with (/sup 99m/Tc)GH. The intensity of uptake was somewhat greater with /sup 67/Ga than with (/sup 99m/Tc)GH in almost all malignant lung tumor groups. The specificity to detect malignant tumors was 82% with both radiopharmaceuticals. Irradiation and chemotherapy seemed to decrease /sup 67/Ga uptake but not (/sup 99m/Tc)GH uptake. Only four of 22 benign diseases showed accumulation of both /sup 67/Ga and (/sup 99m/Tc)GH. The intensity of uptake in benign processes was almost equal with that in malignant diseases, but most malignant processes were better delineated than the benign lesions. There were many differences between /sup 67/Ga and (/sup 99m/Tc)GH uptake, which suggest different mechanisms of accumulation of these agents. It is concluded that some /sup 67/Ga studies could be replaced by cheaper and more practical (/sup 99m/Tc)GH.