INTRA-ARTICULAR YTTRIUM 90 INJECTION AS AN ADJUVANT FOLLOWING RESECTION OF DIFFUSED PIGMENTED VILLONODULAR SYNOVITIS

Introduction: Diffused pigmented villonodular synovitis (PVNS) is a locally aggressive lesion for which surgery provides only marginal resection. An adjuvant treatment modality is therefore required to prevent local tumor recurrence. The authors describe their experience with intra-articular injection of Yttrium 90 (Y 90 ), a radioisotope, as an adjuvant for tumor resection. Materials and Methods: Between 1989 and 2002, 20 patients with diffuse PVNS were treated with post-operative, intraarticular injection of Y 90 . There were 15 male and 5 female patients who ranged in age from 13 to 67 years (mean, 35 years). Anatomic locations of the affected joints included: knee – 15, ankle – 4, hip – 1. Tumor resection was initially done in all patients: 13 patients required open arthrotomy, the remaining 7 underwent arthroscopic tumor resection. Ten patients were referred for treatment after having operation for a local tumor recurrence: 6 patients had one, 2 had two, 1 had three, and the remaining one had five local recurrences. Six to eight weeks after surgery, intraarticular injection of 15–25 mCi of Y 90 was done. These procedures were conducted in the operating room under local anesthesia and fluoroscopic guidance. All patients were followed for a minimum of two years (range, 25–168 months; mean, 65 months). Results: Following Y 90 injection, all patients reported mild pain around the affected joint. This pain was well controlled with the use of NSAID’s and typically resolved within a few days or weeks. Three patients had superficial skin inflammation and associated blisters around the site of injection, probably the result of Y 90 effect on the soft-tissues. All were treated conservatively with complete resolution of their symptoms. All patients gained their pre-injection range-of-motion within 4–6 weeks. At the most recent follow-up, five patients had transient post-radiation skin changes (discoloration of the skin and dry and scaly skin) and local recurrence occurred in only one patient (5%) with PVNS around the knee; additional Y 90 injections were unsuccessful and he eventually underwent knee arthrodesis. Conclusion: Y 90 injection is a reliable adjuvant for surgery in the management of diffused PVNS. Local tumor control and good function, associated with only mild morbidity are achieved in the majority of the patients.