Radiotherapy for Intraarticular Venous Malformations of the Knee

Intraarticular venous malformation (IAVM) of the knee is a rare vascular disease that manifests with pain, swelling, and hemarthrosis. A young man with left knee pain and swelling was admitted to our institution for the treatment of the IAVM of the left knee which was diagnosed by a local orthopedic doctor via arthroscopy. A total dose of 40 Gy of radiotherapy was delivered with a daily dose of 2.0 Gy using 6 MV X-ray beams and a linear accelerator through anteroposterior portals. Fifteen months after radiotherapy, follow-up examination using radiologic imaging showed distinct shrinkage of the venous malformations. Swelling and pain of the left knee had decreased, and range of motion of the left knee was maintained. This report describes a case involving a 38-year-old man with IAVM of the left knee in whom favorable outcomes were obtained in response to radiotherapy.