What are the surgical and oncologic outcomes, as well as the complications, associated with pre-operative radiotherapy in patients with low-grade soft-tissue sarcoma?

BACKGROUND

Surgery with radiotherapy is a standard choice for high-grade soft-tissue sarcoma; however, the indication of radiotherapy for low-grade soft-tissue sarcoma remains controversial due to an inherent low risk of distant metastasis and recurrence after surgery, as well as potential complications after surgery.

METHODS

Between 2007 and 2020, a total of 132 patients with low-grade soft-tissue sarcoma treated with pre-operative radiotherapy followed by surgical resection were examined. Pre-operative radiotherapy was administered with 50.4 Gy in 1.8 Gy fractions, with definitive surgery performed 4-8 weeks after completing pre-operative radiotherapy to allow inflammation to subside. Optimal methods for wound closure were performed by plastic surgeons, with the selective use of flap reconstructions (pedicled or free), skin grafts or direct closure.

RESULTS

Diagnoses included well-differentiated liposarcoma/atypical lipomatous tumors (n = 66), myxoid liposarcoma (n = 31), leiomyosarcoma (n = 22), and others. After en-bloc (wide) resections, 78.8% (104/132) underwent plastic reconstruction, including free flaps (51.5%), pedicled flaps (25.8%), and skin grafts (1.5%). The resection margins were R0 in 93.2% (123/132), R1 or R2 in 6.8% (9/132). The 5-year local recurrence-free rate was 99.1%, and distant metastasis-free survival was 90.6%, with nine metastases observed, mainly in myxoid liposarcoma. The disease-specific survival at 5 years was 99.2%. Wound complication-related reoperations occurred in 21.2% (28/132), with similar rates between direct closure (21.4%, 6/28) and plastic reconstruction (21.2%, 22/104, p = 0.705).

CONCLUSION

Although surgical and oncological outcomes were favourable, the efficacy and invasiveness of pre-operative radiotherapy should be carefully balanced based on the patients' individual background, due to the potential post-operative complications.