[The indication for radiosynoviorthesis. From the perspective of the nuclear medicine expert, rheumatic orthopedist and internist].

Radiosynovectomy or radiosynoviorthesis (RSO), the intra-articular injection of beta-emitting radionuclides (e.g. colloidal preparations of 90-Yttrium, 186-Rhenium or 169-Erbium), is an approved, reliable and easily performed therapy for the treatment of chronic synovitis without harmful side effects. The best clinical results have been obtained in patients with predominantly inflammatory joint disease such as rheumatoid arthritis or reactive arthritis. But RSO is also established to treat pain and persistent effusions after total knee replacement. It also represents an adjuvant therapy in patients with pigmented villonodular synovitis to protect against recurrence following synovectomy. In patients with hemophilia and arthropathy a reduction in joint bleeding is seen and the use of coagulation factor is reduced. The indication for RSO should be made in close cooperation between the referring physician, the rheumatologist and the nuclear medicine expert in the context of a multimodal therapy concept. In this way, success rates of over 80%, with only few side effects, can be achieved, particularly in rheumatoid arthritis, reactive arthritis and hemophilic arthropathy.