Radioactive nucleic acids-precursors: their potential value as tumor-localizing agents.

The distribution of 125I-uracil and 125I-deoxyuridine in tumor-bearing animals has been studied. 125I-deoxyuridine shows the characteristics of a tumor-scanning agent. The metabolic incorporation by tumors of this DNA-precursor indicates a potential value of this radiocompound for their detection, differentiation and follow-up of their evolution after therapy.