Abstract
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Introduction: The study aimed at evaluating the therapeutic utility of radiosynovectomy (RSV) procedure using in-house prepared 188Rhenium labelled tin colloid in patients with symptomatic inflammatory arthropathy intractable to standard medical/surgical therapies.
Methods: Twenty two patients (mean age: 34.8±14.3 years; male/female: 16/6) underwent RSV in a total of 24 joints (single knee in 21 patients, both knees and right ankle in one patient) using intra-articular injection of in-house prepared 188Re-tin colloid (mean activity 521.7 MBq in knee and 333 MBq in ankle). The indications of therapy were synovitis (not otherwise specified) in 10 joints, pigmented villo-nodular synovitis in 9, rheumatoid arthritis in 3 and primary synovial chondromatosis in 2 joints, either diagnosed on arthroscopic sampling and histopathology (in 13 joints) or clinical/radiological assessment in rest of the joints. All the patients who underwent RSV procedure had active arthropathies intractable to conventional medical or surgical (arthroscopic debridement) procedures. All patients had three-phase bone scan showing active bony inflammation prior to the procedure and assessment of symptom scoring for pain (0=10, 0=no pain, 10=extreme pain), range of motion (1-135º, 135º as full flexion for knee), effusion (joint girth in cm at mid patellar level) were done. A post-therapeutic one-hour as well as 48-hour planar imaging confirmed localization and uniform distribution of tracer activity within the synovial cavity. Follow-up was done at 3, 6 months post therapy with clinical assessment/three-phase bone scan at 6 months and long-term median follow-up duration was 40.0 (range 1-72 months).
Results: The procedure was tolerated well by all patients and no procedure related complication was noted in any patient. Reduction in pain (mean % reduction of 55.2) and effusion was noted in 18/24 joints (with complete resolution of pain and analgesic free in 5) and additional increase in range of flexion in 7 out of these 18 joints (mean increase of 27.1º), at 3 months follow up. No reduction in pain score was reported in 5 joints (stable disease) and increase in the pain score were noted in one joint despite therapy. Adjuvant therapy in the form of arthroscopic debridement post-radiosynovectomy was possible in 3 patients. We observed substantial radiation induced dense hyalinization in the treated joints (with RSV) which facilitated en-bloc resection of the involved synovium, unlike the cumbersome piecemeal technique in synovial chondromatosis, highlighting the potential ‘neo-adjuvant’ role of this technique prior to definitive surgery1. Four patients had recurrence/increase of symptoms for which redo therapy (RSV was done in the same joints after six months) was done. 12/22 patients (54.5%) reported reduction/stabilization in symptoms at the long-term follow up.
Conclusions: Radiosynovectomy in large joints using in-house 188Re-tin colloid is feasible, safe and effective therapy in patients with refractory arthropathies2 and the present study result showed good clinical utility as well as potential adjuvant role to arthroscopic debridement.