5-fraction preoperative RT exhibits top-notch local control for soft tissue sarcoma

Patients with soft tissue sarcoma (STS) who underwent preoperative 5-fraction radiation therapy (RT) exhibit excellent 2-year local control with major wound complications (MWC) and experience toxicity akin to standard fractionation preoperative RT, a study has shown.

Researchers used Bayesian methods for this study-level meta-analysis, and they also performed statistical estimation for risk of outcomes rates by posterior mean and 95 percent highest posterior density (HPD) intervals.

Studies with available data on the primary outcomes of 2-year local control and descriptions of MWC per the CAN-NCIC-SR2 study were eligible. Other endpoints assessed were rates of acute and late toxicity. Ten studies were identified, of which seven were included in the meta-analysis. The research team also conducted subgroup analyses for ≥30 vs <30 Gy.

Eligible studies included a total of 209 patients. Five studies used ≥30 Gy (n=144), and the other two used <30 Gy (n=64). The median follow-up was 29 months.

The location of the primary tumour was in the lower extremity (68 percent), and a few were found in the upper extremity (22 percent). Most tumours were intermediate or high grade (n=160/169, 95 percent), and half of these (n=79/158, 50 percent) had a size of >10 cm.

The entire cohort had a 2-year local control rate of 96.9 percent and an MWC rate of 30.6 percent. A trend toward improved local control was noted with ≥30 Gy (95 percent HPD, 0.95‒0.99 vs 0.84‒0.99). No between-group difference was observed in either MWC (95 percent HPD, 0.18‒0.42 vs 0.17‒0.55) or late toxicity.

“Multi-institutional trials with a universal RT protocol are warranted,” the researchers said.