Long-term chromosomal effects of radiation synovectomy in rheumatoid arthritis patients

Micronucleus tests and chromosomal aberration assays were performed to evaluate long-term chromosomal damage in rheumatoid arthritis patients treated by intraarticular injection of a commercially prepared colloid of the β-emittent yttrium-90 radioisotope. We conducted a long-term follow-up study (24 months) of a group of seven patients undergoing radiosynoviorthesis. At 24 months there was still a significant increase in micronucleus values as compared to basal levels. On the other hand, chromosomal aberrations diminished, becoming non-significant as compared to basal values. The persistent significance of micronucleus values after 24 months indicated lasting chromosomal damage 24 months after yttrium-90 intra-articular injection. For this reason, the treatment is not recommended as the therapy of choice in young patients.