title: Treatment of pigmented villonodular synovitis with yttrium-90: changes in immunologic features, Tc-99m uptake measurements, and MR imaging of one case.
abstract: Pigmented villonodular synovitis (PVNS) is an uncommon proliferative disease of synovium. We report a 35-year-old male with diffuse form of PVNS of left knee, treated with intraarticular injection of 5 mCi of yttrium-90 (Y-90) silicate colloid consisting of two doses with a 3-month interval between them. During follow-up, the affected knee showed clinical improvement and was accompanied by a decrease of the levels of soluble interleukin-2 receptor in sera and synovial fluids (SF). When compared to osteoarthritis subjects, SF lymphocyte subsets of this case before Y-90 therapy showed a lower CD4:CD8 cell ratio and absence of suppressor inducer cells (CD4+ 2H4+). The Tc-99m pertechnetate knee uptake indexes correlated well with clinical improvement. Serial magnetic resonance imaging revealed significant change one year after Y-90 therapy. The findings of immunological assessment suggested that immunoregulatory dysfunction may be related to the pathogenesis of PVNS.
authors.affiliation: Department of Allergy, Immunology and Rheumatology, Taichung Veterans General Hospital, Taiwan.
authors.forename: D Y
authors.initials: DY
authors.lastname: Chen
authors.forename: J L
authors.initials: JL
authors.lastname: Lan
authors.forename: S J
authors.initials: SJ
authors.lastname: Chou
mesh_terms: D000328:Adult; D006801:Humans; D016131:Lymphocyte Subsets / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D013670:Sodium Pertechnetate Tc 99m / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism; D013586:Synovitis, Pigmented Villonodular / Q000276:immunology / Q000532:radiotherapy*; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
chemical_list: D015021:Yttrium Radioisotopes; D013670:Sodium Pertechnetate Tc 99m