# Preoperative Chemoradiation (Modified Eilber Protocol) Versus Preoperative/Postoperative Radiotherapy for Soft Tissue Sarcomas: A Population-Based Analysis

## TL;DR

This study compares a modified preoperative chemoradiation protocol to standard radiation treatments for soft tissue sarcomas and finds similar outcomes in terms of survival and recurrence.

## Contribution

The study provides population-based evidence that a modified preoperative chemoradiation protocol is non-inferior to standard radiation treatments for soft tissue sarcomas.

## Key findings

- The modified Eilber protocol showed no significant differences in local recurrence compared to standard preoperative or postoperative radiotherapy.
- There were no significant differences in overall survival or recurrence-free survival between the treatment groups.
- The modified protocol uses lower radiation doses and chemotherapy, potentially reducing side effects.

## Abstract

Soft tissue sarcomas are rare cancers that can occur in the extremities or trunk and are usually treated with limb sparing surgery. Treatments often includes radiation therapy to lower risk of recurrence after a surgery. However, standard preoperative or postoperative radiation can cause significant side effects, and it is unclear which method is best. This study looked at how a well a shorter, lower-dose of preoperative radiation combined with a small dose radio-sensitizing chemotherapy compared to standard treatments. Using data from all sarcoma patients treated in our province over the span of 12 years, we found that this approach may provide similar outcomes in terms of survival and recurrence. These findings could help guide future studies on this approach and potentially offer an alternative to current treatment approaches.

Background: Local recurrence for high-risk extremities/trunk soft tissue sarcoma (STS) after treatment can range from 15 to 30%. The modified Eilber protocol (MEP) using low-dose intravenous chemotherapy with a reduced dosage of radiation in the preoperative setting has demonstrated excellent local control and reduced wound complications in these patients. The aim of the current study was to assess long-term local control and overall survival in patients with STS treated with the MEP versus standard preoperative or postoperative radiotherapy. Methods: Patients diagnosed with STS from 2004 to 2016 were identified using the Alberta Cancer Registry. Patients with STS treated with the MEP, preoperative or postoperative radiotherapy, were included. Patient and tumor characteristics, treatments and outcomes were abstracted from the registry and primary chart review. Characteristics were compared using one-way ANOVA for continuous variable and chi-square test and Fisher test for the categorical outcomes. Local recurrence-free survival and overall survival were analyzed using Kaplan–Meier Analysis with Log-rank test. Results: A total of 242 patients with STS were included, among which 100 (41.3%) received the MEP prior to surgery, 91 (37.6%) had preoperative radiation, and 51 (21.1%) had postoperative radiation. After a median follow up of 4.9 years, there were no significant differences in local recurrence or local recurrence-free survival between patients treated with the MEP vs. preoperative or postoperative radiotherapy (10 vs. 6.6% and 7.8%, respectively, p-value NS). There were also no significant differences between groups for recurrence-free survival and overall survival. Conclusions: This study demonstrates that the use of the MEP has non-inferior oncologic outcomes compared to standard preoperative or postoperative radiation in a population-based analysis despite reducing the overall dosage of radiation administered. The modified Eilber preoperative chemoradiation protocol may be considered as an additional option for patients with STS.