Intra-articular yttrium 90 in rabbits. Comparison of behaviour of various radiocolloids in rabbits and in man.

Abstract

SUMMARY Comparative studies of the retention of various yttrium 90 radiocolloids and of noncolloidal yttrium 90 chloride were performed in rabbits with arthritis induced in one knee. Two colloids, the citrate and resin forms, showed a statistically significant difference in retention between inflamed and normal knees, isotope being retained better in the normal knee. Marked djlerences were found in the handling of the various yttrium preparations in rabbits compared with previously reported results in man. These al., 1973a;Bayly et al., 1973). These initial experiments were extended to see whether more could be learnt about the role of particle size and colloidal form in the handling of radiocolloids by the synovium.Marked differences in the handling of the various colloids were found between rabbits and man. An interesting difference between normal and inflamed knees in rabbits was noted in terms of retention of two of the four radiocolloids used. Materials and methodsCertain characteristics of the radiocolloids are shown in the Table. A part of routine batches of 90Y citrate, ferric hydroxide, and silicate ordered for human use was used in rabbits. 90Y resin colloid is no longer manufactured and a special consignment was supplied for this experiment. Additionally, 90Y chloride, the raw material from which some of these colloids are made, was also used.Accepted for publication July 21, 1977 A Dumonde-Glynn form of chronic synovitis was induced in the right knee of each rabbit by intraarticular injection of gammaglobulin after sensitisation with gammaglobulin. Rabbits were immunised in batches of 6 and then challenged so that animals of one batch could be used for more than one radiocolloid. 100 ,uCi 90Y was injected into each knee of 3 rabbits at one time; one rabbit would be sacrificed at intervals of 24 hours, 48 hours, and 16&6hours. Both knees, regional lymph nodes, and liver were separately removed and counted. Immediately after counting, some synovium was processed for autoradiography.The 90Y content (Ti = 64 hours; maximum beta energy = 2.27 MeV) of each sample was determined by measurement of the bremsstrahlung using two

Pretreatment macrophage infiltration of the synovium predicts the clinical effect of both radiation synovectomy and intra-articular glucocorticoids

“…The size of the colloidal particles is important for their retention in the synovial membrane; 90 Y citrate used in our study has small colloids and seems to be associated with more leakage from the joint, with subsequently more extra-articular spread than larger colloids such as 90 Y silicate. 42 RSO may result in coagulation necrosis of the superficial layer of the synovium within 2 weeks after treatment with 90 Y, as has been shown both in animal models 41 43-45 and in patients. 46 Severe damage of the cytoplasmic ultrastructure of the synovial lining cells has been reported 3 days after RSO.…”

Treatment of Antigen-Induced Arthritis in Rabbits by the Intra-articular Injection of Methylprednisolone, 90Y or Chlorambucil

“…Alternatively, a synovectomy can be effected by injecting a radionucleotide into arthritic joints to irradiate and destroy the diseased synovium. Irradiation synovectomy was first performed using colloidal I9*Au (Ansell et a1 1963), but 90Y is now the radionucleotide most commonly used because of its more penetrating j-radiation (Gumpel 1978;Menkes 1979).…”