The treatment of periarticular soft tissue sarcoma following neo-adjuvant radiotherapy: a cohort study.

Background: Optimising post-operative joint function is challenging when treating periarticular soft tissue sarcoma (STS). Radiotherapy reduces local recurrence rates but periarticular fibrosis may adversely affect joint function. Neo-adjuvant radiotherapy requires lower doses and smaller treatment volumes and therefore has potential benefits for the management of periarticular STS, but has previously been shown to be associated with an increased risk of post-operative wound complications. This study assesses initial outcome and complications after treatment with neo-adjuvant radiotherapy and surgery for patients with periarticular STS.

Methods: Seventeen patients (mean age 52.5 years) were treated using a standard protocol between January 2009 and June 2012 with three-dimensional conformal neo-adjuvant radiotherapy to a dose of 50 Gy in 25 fractions at a single centre, followed by limb salvage surgery. Patients were assessed weekly for adverse effects during radiotherapy. Surgery was planned for 6 weeks following completion of radiotherapy. Patients remain under follow-up with regular Toronto Extremity Salvage Scores (TESS) performed.

Results: No patients had a significant adverse effect during radiotherapy. Three patients (17.6%) suffered a wound complication following surgery, all treated conservatively. Magnetic resonance imaging (MRI) demonstrated a reduction in mean maximal tumour diameter from 7.56 to 5.24 cm (p = 0.017, 11 of 17 patients). Tumour necrosis was measured between 50% and 100% in 10 of 11 resections where accurate assessment was possible. One patient had further surgery due to incomplete margins. No patients required post-operative radiotherapy. No local recurrences have occurred after a mean follow-up of 32 months (range 19 to 59 months). Two patients have developed metastatic disease. Mean TESS scores for upper and lower limb patients were 98.5 and 85.5, respectively, at latest follow-up.

Conclusions: We have demonstrated improved wound complication rates compared to the existing literature on the use of neo-adjuvant radiotherapy. This may relate to modification of the technique and patient selection compared to previous series. Excellent functional outcomes can be obtained with this treatment strategy.