Does fluid collection impact radiotherapy outcomes after wide excision of lower extremity soft tissue sarcoma?

Fluid collection (FC) of lymph or blood may accumulate at the site of excision after surgery for soft tissue sarcoma, with reported incidence rates from 10% to 36%. The purpose of this study is to analyze the impact of FC on local recurrence (LR) and wound complication rates after adjuvant postoperative radiotherapy (PORT) in lower extremity soft tissue sarcoma (LE-STS).

Eighty-eight patients diagnosed with LE-STS were curatively treated with wide excision and PORT. FC developed in 51.1% of patients. Full FC volumes were included in the irradiation field throughout the full course of PORT for 36 patients (80.0%). A median of 61.2 and 63 Gy was prescribed for patients with and without FC, respectively.

After a median follow-up of 4.3 years, patients with and without FC had 5-year local control rates of 77.7% and 90.8% (P = 0.105). Eight patients with FC had LR, of which six patients had recurrent tumors at or within 4 cm of the FC wall and three of these patients had out-of-field LR. Wound complication occurred after RT in 3 (6.7%) of 45 patients with FC and 1 (2.3%) of 43 patients without FC.

FC presents a potential risk for increased LR, particularly near the FC wall. Based on reasonable wound complication rates, we suggest the need and feasibility of fully including FC volumes in the irradiation field.