The Influence of Tumor Stage and Metastasis on the Biodistribution of Gallium-67 Citrate in the Murine Lewis Lung Carcinoma Model

which the primary tumor was amputated along with adjacent fragments of the tail tissue. Gamma camera scintigraphy and dissection/radiometric biodistribution studies indicated that: (a) tumors and mA©tastasestook up 5-6% of the injected dose/g except when large necrotic areas were present in the primary tumor; (b) blood levels of 67Gaincreased in all tumorbearing animals, with up to tenfold increases in the i.m. tumor model at later stages of the growth; (c) hepatic uptake increased as a function of tumor size/age, and (d) all tissue:blood ratios declined as the neoplastia tissues progressed. The results are discussed with respect to tumor progression and metastatic disease.