Persistent synovitis treated with radiation synovectomy using yttrium-90: a retrospective evaluation of 83 procedures for 45 patients.

The objectives were to investigate the efficacy and safety of yttrium-90 colloid (Y-90) synovectomy in joints with persistent synovitis and to examine the effect of a second synovectomy using a double dose after an initial inadequate response. Of the 45 patients at the University Hospital Utrecht who underwent Y-90 synovectomy between July 1987 and October 1995, the effectiveness and side-effects of all yttrium procedures (n = 83) were assessed retrospectively. Glucocorticoids were administered together with the yttrium, except in 1987. Radiation synovectomy had an overall success rate of 75% (complete or almost complete remission of synovitis) initially, i.e. within 1 month of the procedure, partly due to co-administration of glucocorticoids. However, in October 1995, only 17 joints (22%) were still in remission with a mean (S.D.) duration of remission of 20.8 months (22.0), range 1-95 months (median 16 months). In 60 joints (78%), synovitis was present at that time because of an unsatisfactory initial response to the Y-90 injection (19 joints) or recurrent synovitis during follow-up (41 joints); the mean (S.D.) duration of remission of these 60 joints was 3.3 months (5.9), range 0-22 months. A second injection of a double dose of Y-90 after an initial inadequate response (n = 8) did not contribute significantly to a better result. Short-term side-effects occurred in two cases after two Y-90 injections (2%) without glucocorticoid co-administration: a post-injection flare-up of synovitis and a local skin burn lesion. Persistent synovitis can be treated by Y-90 synovectomy with an overall success rate of 75% within 1 month. However, prolonged remission of synovitis is only achieved in 29% of joints with a good initial response. It does not appear worthwhile to perform a second synovectomy with a double dose if the initial response was inadequate. Y-90 synovectomy leads to only minor short-term side-effects (2%).