A COMPARATIVE-STUDY OF THE SAFETY AND EFFICACY OF DYSPOSIUM-165 HYDROXIDE MACRO-AGGREGATE AND Y-90 SILICATE COLLOID IN RADIATION SYNOVECTOMY A MULTICENTER DOUBLE-BLIND CLINICAL-TRIAL

The aim of our study was to compare the safety and efficacy of a new p reparation, Dysprosium-165 Hydroxide Macro-aggregate (Dy-165) with Ytt rium-90 Silicate (Y-90) for radiation synovectomy of the knee in patie nts with RA and OA. A multicentre double blind clinical trial with sub jects randomized to receive Dy-165 or Y-90 was undertaken in Sydney, M elbourne and Perth. Seventy knees of 59 patients were studied, using a s clinical end point measurements, pain in the knee on walking, pain i n the knee at rest and stiffness in the knee after rest. Cytogenetic d amage, knee retention and extra-articular spread of the radionuclide t o regional lymph nodes, liver, urine and blood were evaluated. There w as no significant difference in clinical response in the two treatment groups for either RA or OA. Chromosomal changes occurred with equal f requency and the knee retention and extra-articular leakage of radioco lloids to regional lymph nodes and liver were comparable in the two gr oups. For radiation synovectomy of the knee, Dy-165 is at least as saf e and as effective as Y-90 and has the advantage of a short half-life (2.334 h) and hence requires a shorter period of post-injection immobi lization and hospitalization.