Optimal post-operative radiation after soft-tissue sarcoma resection is achieved in less than two thirds of cases.

Purpose: Local control of soft tissue sarcomas frequently involves adjuvant radiation to the surgical resection. When opting for post-operative radiation, care should be taken that radiation is started within some reasonable time after the surgery. We were interested to the proportion of patients who did not recieve optimal post-operative radiation and the variables associated.

Methods: We retrospectively analyzed a series of 77 patients operated on for an extremity soft-tissue sarcoma and due for post-operative radiotherapy. Patients were considered to have received radiation optimally if radiation was started within 12 weeks of surgery. Variables associated with not receiving radiation optimally were looked for using univariable and multivariable regression models.

Results: Overall, 26 patients (34%; 95% CI: 23-45%) did not receive radiation optimally. Twenty (26%) did not start radiation within the 12-weeks mark and six (8%) could not have radiation at all. The main reason identified for not receiving radiation on time was the occurrence of a wound complication (14 (54%) patients). An increased body mass index (OR: 1.14; 95% CI: 1.02-1.26; p = 0.02) and an older age (OR: 1.55; 95% CI: 1.18-2.14; p = 0.04; of note, the OR are for a 10 year change) were significantly associated with not receiving radiation optimally. Patients with a social fragility (p = 0.04), metastatic spread at presentation (p = 0.04), and increased duration of surgery (p = 0.02) were more likely to develop a wound complication.

Conclusions: About 34% of patients do not receive optimal post-operative radiation treatment. Older and obese patients have a higher risk of not receiving radiation optimally. The decision for pre- or post-operative radiation should account for these findings.