Role of rhenium-188 tin colloid radiosynovectomy in patients with inflammatory knee joint conditions refractory to conventional therapy.

AIM

To evaluate the treatment response of rhenium-188 (¹⁸⁸Re) tin colloid radiosynovectomy (¹⁸⁸Re-RSV) in patients with inflammatory knee joint conditions refractory to conventional treatment.

MATERIALS AND METHODS

Sixty-one knee joints in 48 patients with chronic synovitis caused by various inflammatory knee joint diseases refractory to conventional therapy were included in this prospective study. All patients were assessed clinically for pain, tenderness, joint swelling, mobility, analgesic intake, and blood pool activity on bone scan. Different scores were assigned to all these parameters. RSV of knee joint was done using intra-articular injection of 555 MBq of ¹⁸⁸Re tin colloid. Response was assessed at 3, 6, and 12 months using various clinical parameter scores and blood pool bone scan mentioned above and categorized as responders and nonresponders on the basis of change in percentage of cumulative scores.

RESULTS

Of the 61 joints, 57 were responder and four were nonresponder at 3-month post-RSV. Out of 57 responders, seven had recurrence on further follow-up (three at 6 months and four at 12 months). There was a statistically significant reduction in clinical parameters cumulative scores at 3, 6, and 12 months when compared with baseline (P<0.0001) in responder group. Blood pool scinitgraphy also showed decrease in blood pool activity compared with the baseline. There was statistically significant association between the responder group and shorter duration of disease (P=0.011). Patients having normal or minor X-ray changes, little or no swelling, mild tenderness, and better mobility were independently associated with good response.

CONCLUSION

¹⁸⁸Re tin colloid synovectomy is a useful treatment modality in patients with chronic inflammatory knee joint conditions refractory to conventional treatment. Patients with shorter duration of disease, normal or minor X-ray findings, little or no swelling, mild tenderness, and better mobility are better candidates for RSV.