(P 295) FROM HISTORICAL REFERENCE TO MODERN PRACTICE: WOUND COMPLICATION RATES IN SOFT TISSUE SARCOMA TREATED WITH RADIOTHERAPY ACROSS ERAS

Objective: Conventional preoperative radiotherapy for soft tissue sarcomas (STS) has historically been associated with a 35% wound complication rate, as reported in the Canadian SR-2 trial in 2002. However, over the past two decades, more recent studies with further advanced radiation techniques suggest a decrease in wound complications with this treatment approach. This study aims to investigate whether the incidence of major wound complications has changed in recent years.

Methods: Patients were included if they were treated with preoperative radiotherapy with a regimen of 25 x 2 Gy between May 2003 and September 2024 in a curative setting. Data was collected on major wound complications within 120 days post-surgery and factors potentially influencing these wound complications. To assess changes in the percentage of wound complications in recent years, patients were stratified into two groups based on treatment date: before 2015 and from 2015 onwards, reflecting the broader adoption of image guided radiotherapy and intensity modulated radiotherapy. To assess differences in wound complications between these time periods, a multivariable logistic regression model was estimated, to adjust for potential confounders. Statistical analyses were performed in SPSS (30.0.0.0).

Results: In total, 155 patients were included, 84 (54.2%) and 71 (45.8%) patients were treated before 2015 and after 2015 respectively. Overall, 41 Patients experienced a major wound complication. The complication rate was 28.6% in the group treated before 2015 and 23.9% from 2015 onwards. Adjusted odds ratio (OR) with 95% confidence interval (CI) for the period was not significant (OR: 1.59 (95% CI 0.62–4.09). Confounding incorporated in the model were sex, age, smoking status, hypertension, adiposity, diabetes mellitus, tumor grade and histology, tumor location and size, and the interval between the last fraction of radiotherapy and surgery.

Conclusion: Our results shows no significant difference in major wound complications following preoperative conventional radiotherapy for STS since 2015. More studies are now focusing on hypofractionation to assess oncological outcomes and treatment-related toxicities. To allow a more accurate comparison between conventional and hypofractionated radiotherapy in terms of wound complications, a head-to-head comparison in a randomized phase II trial is needed to clarify the impact of modern radiotherapy and surgical techniques on wound complication rates.