title: Radiation synovectomy with (166)Ho-ferric hydroxide: a first experience.
abstract: Radiation synovectomy (RS) is indicated when conventional pharmacologic treatment of chronic synovitis has not relieved its symptoms. The use of radionuclides that are bound to ferric hydroxide (FH) particles has been shown to be effective and safe for this procedure. (166)Ho-FH macroaggregates offer promising properties for RS but there is a lack of clinical data. We investigated the efficacy and safety of (166)Ho-FH in a prospective clinical trial in patients suffering from chronic synovitis.
  
  
  METHODS
  Twenty-four intraarticular injections were performed in 22 patients receiving a mean activity of 1.11 GBq (range, 0.77-1.24 GBq) (166)Ho-FH. Blood activity measurements and monitoring of activity distribution were performed by whole-body gamma-camera imaging for control of leakage 3 and 24 h after injection of (166)Ho-FH. The patients were evaluated clinically before RS, 1 wk and 1 mo after the treatment, and thereafter in 3-mo intervals by assessing joint effusion, pannus, local pain, range of motion, and the patient's satisfaction.
  
  
  RESULTS
  In 18 of 24 treatments, no leakage to nontarget organs was visible, whereas small amounts of activity could be detected in the local inguinal lymph nodes in 6 patients and to the lungs and to the liver in 1 patient (<0.1%). In all cases leakage to the lymph nodes was <1%. Leakage to the blood was negligible. Clinically, 17 patients (71%) exhibited a complete or partial response.
  
  
  CONCLUSIONS
  RS with (166)Ho-FH was safe and effective in patients with chronic synovitis of different origin. Controlled clinical trials are necessary to evaluate the therapeutic efficacy and safety compared with the treatment with other radionuclides and glucocorticosteroids.
authors.affiliation: Department of Nuclear Medicine, University of Vienna, Austria.
authors.forename: Sedat
authors.initials: S
authors.lastname: Ofluoglu
authors.forename: Eva
authors.initials: E
authors.lastname: Schwameis
authors.forename: Harald
authors.initials: H
authors.lastname: Zehetgruber
authors.forename: Ernst
authors.initials: E
authors.lastname: Havlik
authors.forename: Axel
authors.initials: A
authors.lastname: Wanivenhaus
authors.forename: Ingrid
authors.initials: I
authors.lastname: Schweeger
authors.forename: Konrad
authors.initials: K
authors.lastname: Weiss
authors.forename: Helmut
authors.initials: H
authors.lastname: Sinzinger
authors.forename: Christian
authors.initials: C
authors.lastname: Pirich
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D005290:Ferric Compounds / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D006695:Holmium / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D006801:Humans; D007270:Injections, Intra-Articular; D007719:Knee Joint / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011868:Radioisotopes / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D013583:Synovial Membrane / Q000528:radiation effects*; D013585:Synovitis / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D014018:Tissue Distribution
chemical_list: D005290:Ferric Compounds; D011868:Radioisotopes; C021024:ferric hydroxide; D006695:Holmium