Identification of predictors for wound complications following preoperative or postoperative radiotherapy in extremity soft tissue sarcoma.

Introduction: In extremity soft tissue sarcoma (ESTS), external beam radiotherapy (EBRT) has been used in addition to limb-sparing surgery (LSS). This study aims to identify predictors for major wound complication (MWC) development following EBRT and LSS in ESTS.

Methods: This retrospective study includes ESTS patients treated with EBRT and LSS between 2005 and 2017. Two groups were formed; Group I included preoperatively irradiated patients, whereas Group II included patients who underwent postoperative EBRT. Multivariate logistic regression analyses were performed to create a prediction model for MWC development.

Results: One hundred twenty-seven patients were included, 58 patients (45.7%) in Group I and 69 patients (54.3%) in Group II. Some differences in baseline characteristics were found between the groups, e.g. in tumor size and grade, histological subtype and total RT dose. Twenty-three patients (39.7%) in Group I and 14 patients (20.3%) in Group II developed a MWC (p = 0.02). Preoperative EBRT was identified as independent predictor for MWC development, OR 2.75 (95%CI 1.21-6.26), p = 0.02. Furthermore, a trend towards an increased MWC risk was shown for patients' age (OR 1.02 (0.99-1.04)), delayed wound closure (OR 3.20 (0.64-16.02)) and negative surgical margins (OR 2.26 (0.72-7.11)). The area under the curve (AUC) of the model was 0.68 (0.57-0.79).

Conclusions: This study corroborates the increased MWC risk following preoperative EBRT in ESTS. It remains important to carefully weigh the MWC risk against the expected long-term functional outcome, and to consider the liberal use of primary plastic surgical reconstructions in an individualized multidisciplinary tumor board prior to treatment.