Efficacy of radiosynovectomy of the knee in rheumatoid arthritis: Evaluation with magnetic resonance imaging

Abstract

The intra-articular injection of a radiopharmaceutical agent (radiosynovectomy) produces a reduction of the synovial inflammatory process. The inflammed synovial membrane can be identified with magnetic resonance imaging after the intravenous administration of gadolinium (MRI-Gd). A 6-month prospective study was carried out in 10 patients with rheumatoid arthritis after radiosynovectomy of the knee. The efficacy was evaluated with clinical parameters and MRI-Gd. A progressive amelioration of synovial effusion, pain, articular range of mobility, total leucocytes count in synovial fluid and synovial membrane thickness through MRI-Gd was observed. The global efficacy was considered to be good in six patients, fair in three and bad in one. The study shows for the first time that MRI-Gd allows the evaluation of the response of the synovial membrane to radiosynovectomy.

Radiation Synovectomy With Holmium‐166 Ferric Hydroxide Macroaggregate in Equine Metacarpophalangeal and Metatarsophalangeal Joints

“…The proliferation of synoviocytes characteristic in control joints was replaced by synovial necrosis in RSYN joints. This reduction in synovial thickness has been associated with a positive clinical response in people with rheumatoid arthritis 39,40 …”

MR Evaluation of Radiation Synovectomy of the Knee by Means of Intra-articular Injection of Holmium-166-Chitosan Complex in Patients with Rheumatoid Arthritis: Results at 4-month Follow-up

“…As a means of evaluating the outcome of radiation synovectomy, investigators have used MR imaging to measure synovial thickness (14, 34). Thickness was found to be reduced by 4.4-7.7 mm at one-year follow-up after 165 Dy treatment (34), and by 1.0-2.3 mm at six-month followup after 90 Y treatment (14).…”

“…Thickness was found to be reduced by 4.4-7.7 mm at one-year follow-up after 165 Dy treatment (34), and by 1.0-2.3 mm at six-month followup after 90 Y treatment (14). However, our results demonstrated no significant change in synovial thickness, which had decreased from 3.8 mm to 3.7 mm at follow-up four months after treatment.…”

“…Joint effusion has been thought to be a therapeutic response indicator (14); as measured by joint aspiration (14) or MRI (10, 11), it has shown reductions after radiation synovectomy ; good correlation was found between the aspirated volume of synovial fluid and the volume of fluid calculated after MRI (11). In our study, the volume of effusion measured by MRI was significantly lower after therapy, and, as was expected, correlated well with the circumference of the knee, an indirect indicator of joint swelling.…”

“…Certain investigators have reported the usefulness of MR perfusion studies in the evaluation of RA, analysing synovial enhancement in terms of its degree and the maximal gradient of increased signal intensity (11), the maximal enhancement ratio (14), the intensity of enhancement (34), the time to maximum synovial lining signal ratio, and the maximum synovial lining signal ratio (13). To determine the usefulness of the quantification of synovial enhancement, further investigation is required.…”