(P 279) IMPACT OF PREOPERATIVE 5-DAY HYPOFRACTIONATED RADIOTHERAPY (HFRT) FOR SOFT TISSUE SARCOMA (STS) ON BARRIERS TO TREATMENT AT A HIGH-VOLUME SARCOMA CENTER (HV-SC)

Objective: Current guidelines for extremity/trunk STS recommend management by an experienced oncology team and preoperative radiotherapy (RT) (50Gy/25 fractions (fx), 5 wks) followed by limb sparing surgery. This study evaluated the feasibility of preoperative 5-Day HFRT (30Gy/5fx) at Holling Cancer Center (HCC), South Carolina’s only HV-SC. An exploratory analysis was performed comparing the sociodemographic profile and travel distance to HCC between the trial cohort and a historical cohort to inform the hypothesis that HFRT decreased barriers to radiotherapy (RT) at a HV-SC.

Methods: The primary endpoint of feasibility was protocol uptake rate, defined as the proportion of eligible patients (pts) who elected to participate in the trial. The trial cohort was defined as those enrolled and treated with at least 1 fx of RT (N=15). The historical cohort (N=8) was defined as those meeting trial criteria and receiving conventionally fractionated RT within the preceding 3 years. The differences in Social Vulnerability Index (SVI) and the geographic distance to HCC were analyzed between the two cohorts using Wilcoxon Rank Sum tests.

Results: Preoperative HFRT was deemed feasible with only one candidate declining the trial, uptake rate of 0.94 (90% CI; 0.77,1.00). Travel distance to HCC was higher in the trial cohort with a median (IQR) of 72.8 (34.6, 101.3) miles, compared to a median (IQR) of 13.2 (2.3, 24.8) miles in the historical cohort (p=0.008). SVI Theme 1 (higher score = more vulnerable) was higher in the historical cohort with a median (IQR) of 0.68 (0.56, 0.85) compared to a median of 0.38 (0.20, 0.46) in the trial cohort (p=0.04). Total SVI and SVI Themes 2-4 were not significantly different between the cohorts (p>0.15).

Conclusion: Preoperative HFRT as a trial treatment option was overwhelming accepted by the HCC STS population. The increased travel distance for the trial cohort suggests a shorter RT treatment option can decrease the geographic barriers to treatment at a HV-SC. The differences in the SVI Theme 1, which correlates with geocode, suggest the preoperative HFRT trial option diversified the sociodemographic profile of HCC STS population.