ON THE SAFETY OF 5-[I-125]IODO-2-'-DEOXYURIDINE - PRECLINICAL EVALUATION IN SWINE

To increase tumor incorporation and minimize hepatic degradation of ra dio-IUdR, compartmental administration routes are being considered as an alternative to intravenous (i.v.) injections, Although there are si gnificant data on the biodistribution and some reports on radiotoxicit y of i.v.-administered (125)IUdR, similar results for other routes of delivery are not available, We have undertaken a series of experiments intended to examine radiation effects of (125)IUdR after intravesical (3 swine; eight 3 mCi doses at 4-day intervals), intracarotid (3 swin e; two 10 mCi doses at 2-week intervals), and intra-aortic (5 swine, s ingle dose of 10 mCi) administration in a swine model, Liver, renal fu nctions, and complete blood counts were monitored throughout the durat ion of the experiment, Pharmacokinetics, systemic distribution of radi oactivity and metabolites were measured, The normal tissue (125)IUdR u ptake and histology were determined after necropsy, No adverse systemi c effects were identified, Clinical observations, laboratory data, and necropsy results were within normal range.