The standard preoperative radiotherapy regimen of 50 Gy delivered in 25 fractions over 5 weeks for soft tissue sarcomas provides excellent local control, with major wound complications occurring in approximately 35% of patients. Our aim was to investigate the safety of a moderately hypofractionated, shorter radiotherapy regimen, which may be more convenient for patients.
Between December 18, 2018 and January 6, 2021, we assessed the eligibility of 157 patients, of whom 120 were recruited and received preoperative hypofractionated radiotherapy. At no time did the calculation of the stopping rule indicate that the trial had to be stopped prematurely for lack of safety. The median postoperative follow-up was 24 months (IQR 17–30). Of 120 patients, 37 (31%, 95% CI 24–40) developed a major wound complication within a median of 37 days (IQR 25–59) after surgery. No patient experienced acute radiotoxicity (during radiotherapy or within 4 weeks of the end date of radiotherapy) grade 3 or worse (Common Terminology Criteria for Adverse Events [CTCAE] version 4.0) or a serious adverse event during treatment. Four (3%) of the 115 patients had late radiotoxicity (≥ 6 months after surgery) of at least grade 3 (CTCAE or Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme): femur fractures (n=2), lymphedema (n=1) and skin ulceration (n=1). There were no treatment-related deaths.
Moderately hypofractionated preoperative radiotherapy delivered to patients with soft tissue sarcomas was safe and therefore may be a more practical alternative to conventional fractionated radiotherapy. Patients can be advised on these results and possibly be offered this regimen, especially if it facilitates management in a specialty center for sarcomas. Results on long-term oncological outcomes, late toxicity and functional outcomes are awaited.
The National Cancer Institute.