Low-dose external beam radiotherapy as a postoperative treatment for patients with diffuse pigmented villonodular synovitis of the knee

Abstract

Background and purposePigmented villonodular synovitis (PVNS) is a rare proliferative disorder involving synovial membranes, and patients with PVNS have a variable prognosis. We retrospectively analyzed clinical outcomes after synovectomy plus low-dose external beam radiotherapy for diffuse PVNS of the knee.MethodsWe reviewed the medical records of 23 patients who underwent postoperative radiotherapy between 1998 and 2007. 19 patients had primary disease and 4 had recurrent disease with an average of 2.5 prior surgeries. After synovectomy (17 arthroscopic surgeries; 6 open), all 23 patients received 4-MV or 6-MV external beam radiotherapy with a median dose of 20 (12–34) Gy in 10 fractions.ResultsAt a median follow-up of 9 (0.8–12) years, 4 patients had recurrent disease, with a median disease-free interval of 5 years. Of these 4 patients, 3 received salvage synovectomy and regained local control. Univariate analysis showed that age, sex, history of trauma, and total dose of radiation were not predictive of local control. 22 patients reported excellent or good joint function, and 1 who refused salvage synovectomy had poor joint function. None of the patients experienced grade 3 or higher radiation-related toxicity or radiation-induced secondary malignancies.InterpretationPostoperative external beam radiotherapy is an effective and acceptable modality to prevent local recurrence and preserve joint function in patients with diffuse PVNS of the knee. Low-dose (20 Gy) radiotherapy appears to be as effective as moderate-dose treatment (around 35 Gy).

Pigmented Villonodular Synovitis for Combined Therapy

“…None of the patient experienced significant radiation toxicity or secondary malignancy in a median F/U of 9 years. Low-dose (20 Gy) RT appears to be as effective as moderate-dose RT (35 Gy) [29].…”

“…One more recent trial describes review of 23 patients after postoperative RT for PVNS [29]. Nineteen patients had primary disease and 4 had recurrent disease with an average of 2.5 prior surgeries.…”

“…Several recent publications showed favorable effect of external beam RT as a postoperative treatment [11,12,18,[28][29][30][31]. The GCG-BD group conducted a pattern-of-care study to analyze the RT for PVNS [12].…”

Arthroscopic synovectomy in pigmented villonodular synovitis of the knee: clinical series and outcome

“…The majority of patients have vague signs and symptoms so arthroscopy is both diagnostic and therapeutic. Diagnosis based on synovial fluid examination has been proposed by [13], synovectomy and arthroplasty [14], low-dose external beam radiotherapy [15] and imatinib therapy [16] etc. Synovectomy is the mainstay of the treatment.…”

Evaluation of patients with diffuse pigmented villonodular synovitis of knee with functional scoring systems after surgery and radiosynovectomy

“…In the advanced stages, a synovial mass may invade the chondro-osseous junction with joint destruction [5]. PVNS of the knee has been reported to have a higher recurrence rate when compared with PVNS of other joints [6]. Surgical excision is the treatment of choice with wide excision in localised disease and total synovectomy in the diffuse form [7].…”