90Yttrium‐hydroxyapatite: a new therapeutic option for radioactive synovectomy in haemophilic synovitis

Summary.  Recurrent haemarthroses often lead to chronic synovitis in patients with haemophilia and von Willebrand disease. Radioactive synovectomy with yttrium‐90 (90Y) citrate is frequently used to treat this complication, usually with good results. Since 2006, the Nuclear Energy Research Institute (IPEN, Sao Paulo, Brazil) has produced hydroxyapatite particles labelled with 90Y for radioactive synovectomy. The aim of this study was to compare the results achieved by both forms of 90Y in the treatment of haemophilic synovitis. We included 221 joints from 136 patients (age range: 6–20 years), treated by one of the two radiopharmaceuticals, at the Hemocenter of Mato Grosso, Brazil. The outcomes analysed were the annual frequency of haemarthrosis, articular pain and joint range of motion before and 1 year after RS. Similar results were achieved regardless of whether 90Y hydroxyapatite or 90Y citrate was used, and results were independent of the joint type, age, gender, radiologic stage and presence of inhibitors. 90Y hydroxyapatite appears to be equivalent to the reference product 90Y citrate in the treatment of chronic synovitis associated with bleeding disorders.