FRI0089 SAFETY AND EFFICACY OF RADIONUCLIDE SYNOVECTOMY IN PATIENTS WITH PERSISTENT INFLAMMATORY OF SINGLE JOINT IN THE COURSE OF BIOLOGICAL THERAPY

Background: Radionuclide synovectomy (RSV) is a form of minimally invasive treatment of persistent joint inflammation. Primary indication for RSV is hypertrophic synovitis refractory to disease-modifying anti-rheumatic drugs (DMARDs), whether synthetic or biological, and intraarticular steroid injections. This procedure has a high rate of success with a low rate of adverse events and complications in properly selected patients. Moreover, due to bactericidal properties of the radiocolloids, the risk of infection after RSV is insignificant, and incidence of post-injection septic arthritis is extremely low. Objectives: To assess safety and efficacy of RSV in patients with inflammatory rheumatic diseases treated with biological disease-modifying anti-rheumatic drugs (bDMARDs). Methods: We analyzed outcomes of 76 radionuclide synovectomy interventions in 47 patients (37 female and 10 male) ongoing biological therapy. The patients were diagnosed as follows: rheumatoid arthritis (RA) – 37, ankylosing spondylitis (AS) – 7, psoriatic arthritis (PsA) – 2 and juvenile idiopathic arthritis (JIA) – 1 patient. The majority of the patients were treated with TNF-alpha inhibitors (79%), which included: adalimumab (31.6%), etanercept (25%), golimumab (14.5%) and certolizumab (7.9%). The other patients were treated with interleukin-6 receptor antagonist tocilizumab (19,7%) and anti-CD20 monoclonal antibody rituximab (1.3%). Patients with overall good response to biologics and persistent inflammation of single joint confirmed by ultrasound PD examination, in case of no contraindications were qualified for RSV procedure. For the RSV following radiopharmaceuticals were used: rhenium-186 sulphide in 41 cases for shoulder (2), elbow (13), wrist (22), hip (2) and ankle (2) joints; yttrium-90 citrate in 27 cases for knee joints; erbium-169 citrate in 8 cases for small joints of hand and feet. All patients had a follow-up visit 3 and 6 months after RSV, during which a clinical and ultrasound examination of the treated joints were performed. Continuous adverse events collection was conducted. Results: The most common indication for RSV was RA – 60 procedures (78.9%), followed by AS – 10 (13.2%), PsA – 4 (5.3%) and JIA – 1 procedure (2.6%). 27 patients had RSV intervention in one joint. 17 patients with satisfactory response to RSV in one joint required radioisotope treatment in another joint (between 2 and 4 different joints were treated in each patient – 13 patients in 2 joints, 5/3 and 2/4). Median patient age was 50 years (21 – 72). Duration of continuous bDMARD treatment preceding RSV was between 1 and 72 months. The intervals between bDMARD administration and RSV ranged from below 24 hours to 4 weeks. Satisfactory effects of RSV, defined as absence of clinical and ultrasound symptoms of inflammation, were observed after 55 (72.4%) interventions. In 11 (14.4%) cases after initial improvement, the inflammation symptoms recurred less than 6 months after RSV. In 10 (13.2%) cases RSV had no effect. No side effects or adverse events occurred after RSV and, most importantly, there were no local or systemic infections observed up to 6 months after the procedure. Conclusion: RSV seems to be an effective single joint treatment method in patients with active synovitis refractory to bDMARDs. Despite increased susceptibility to infection in patients partially immunocompromised and biological treatment, no septic complications were observed after RSV. RSV does not require discontinuation of biological treatment, unlike surgical synovectomy. Disclosure of Interests: Anna Felis-Giemza: None declared, Marek Chojnowski: None declared, Julita Rejmer: None declared, Leszek Krolicki: None declared, Marzena Olesinska Consultant for: F. Hoffmann-La Roche