Comparison of 90Y ferric hydroxide colloid with the citrate and resin colloids. A preliminary animal study.

This was a preliminary evaluation of 90Y ferric hydroxide colloid for the Radiochemical Centre before using it in patients. Autoradiographs of rabbit knees, both inflamed and non-inflamed, showed that the material was evenly distributed in the synovium, and that there was no evidence of aggregation in vivo. Table I shows the retention of ferric hydroxide colloid in the knees of nine rabbits killed at different intervals, compared to a standard aliquot dispensed at the same time. Three separate batches of ferric hydroxide colloid were used. After the animals had been killed, the knees, liver, and popliteal and inguinal lymph nodes were removed and the radioactivity counted. One batch of resin colloid and one batch of citrate colloid were similarly studied. We