Initial experience with intra-articular ¹⁸⁸Re-tin colloid as a "radiation synovectomy" agent in various joints

Radiation synovectomy has been proposed as a promising palliative therapy for recurrent joint effusions for the last two or three decades. Ionizing radiations emitted by intrarticularly administered radiolabelled colloids. The aim of this study was to assess the effectiveness of radiation synovectomy (RSV) using $^{188}Re$-tin colloid in the treatment of recurrent joint effusions and chronic synovitis of knee joints. Three phase bone scan was acquired for the concerned joint prior to radiosynovectomy. $^{188}Re$-tin colloid was prepared as per the reported protocol. 9 patients, diagnosed with rheumatoid arthritis and suffering from chronic resistant synovitis of the knee, ankle or elbow joints were administered the radiopharmaceuticals, checked for radiochemical purity >95% by intraarticular route. A whole body scan was acquired 2 h post-radiosynovectomy. In all the 9 treatments, no leakage to non-target organs was visible in the whole body scan. Static scans of the joint revealed complete retention of $^{188}Re$-tin colloid in the joints post administration of the agent. Clinically all patients exhibited a complete or partial response. RSV with $^{188}Re$-tin colloid was safe and effective in patients with chronic synovitis of rheumatoid origin.