Top Line: Does hypofractionated neoadjuvant radiation for soft tissue sarcoma increase the risk of wound complications?
The Study: The standard regimen for neoadjuvant radiation for STS is 50 Gy in 25 fractions. Could 3 weeks of hypofractionated radiation be just as effective without increasing toxicity? HYPORT-STS was a single center, single arm, phase 2 trial where 120 patients receiving neoadjuvant radiation for extremity STS received 42.75Gy in 15 fractions. The CTV was a standard 3-4 cm craniocaudal and 1.5 cm radial expansion of the MRI-defined GTV. For subcutaneous tumors, the CTV was a 3-4 cm radial expansion with a 0.5-1 cm expansion into the deep, uninvolved muscle compartment. Treatment planning objectives included bone V35Gy <65%, bone mean dose <30.5 Gy, joint V42.75Gy <50%, and femoral head V38Gy <50%. Circumferential prescription dose to the bone was also avoided. There was no acute grade 3+ toxicity, and 3% had late grade 3+ events including two fractures, lymphedema, and a chronic wound. Resection was done a median of 5.7 weeks after radiation, 90% of patients had margin negative resection, and 79% had a plastic/reconstructive surgery wound closure. Major wound complications occurred in 31%, and 76% of those involved the lower extremity. This rate of wound complications is similar to that seen in a randomized trial of pre- versus post-operative RT. The rate of local recurrence was 5%, but median follow up was just 16 months.
TBL: This nonrandomized trial found that toxicity and wound complication risk from moderately hypofractionated, neoadjuvant RT for STS is comparable to historical rates seen with conventional fractionation. | Guadagnolo, Lancet Oncol 2022