Uptake of radioactive phosphorus in experimental tumors. I. Comparison of radioactivity in neoplastic and normal ocular tissue.

For several years we have been pursuing clini cal investigations relating to uptake of radioactive phosphorus (P32) by neoplastia and inflammatory lesions within the eye, and to the development of criteria for diagnostic interpretation and evalua tion of differential radioactive counts in normal and diseased tissues. This method of diagnostic study of eye lesions was suggested by previous ex perimental and clinical studies (2, 9, 12, 13-16) on uptake of radioactive material by malignant tis sue, particularly the work by Selverstone and his associates (16), who, in 1949, demonstrated the usefulness of P32 in the localization of brain tu mors. The close relationship, both embryologically and histologically, between the central nervous system and the structures of the eye made ophthalmologic investigations in this area logical and in evitable. In our first studies (18), our immediate aim was to develop a reliable diagnostic test for malignancy in questionable cases presenting reti nal detachment. During the past 3 years, data have been accumulated in approximately 100 cases of intraocular lesions of various types (10, 11, 19). The technic has been modified and improved, par ticularly by the development of special ocular Geiger counter probes, which made possible more accurate radioactive counts over posterior ocular lesions (17). As this work continued, it became increasingly desirable to build a firmer foundation for these empirical clinical observations by means of con trolled experiments in animals. In planning such investigations, it was possible to take advantage of what had already been learned in two areas of experimentation in which a great volume of work had previously been done.