Surveillance Imaging Patterns and Outcomes Following Radiation Therapy and Radical Resection for Localized Extremity and Trunk Soft Tissue Sarcoma.

Background: Optimal surveillance imaging (SI) regimens following radiation therapy (RT) and radical resection for localized soft tissue sarcoma (STS) are unknown and practice patterns vary.

Methods: Between 2006 and 2014, 94 patients with localized STS of the extremity/trunk treated with preoperative RT and radical resection were identified. Timing of local recurrence (LR), distant recurrence (DR), and SI were evaluated. The Kaplan-Meier method was used to determine recurrence-free and overall survival (OS), and the method of recurrence detection (SI or due to signs/symptoms) was determined.

Results: Median tumor size was 7.5 cm, and 92% were intermediate/high grade. After a median follow-up of 60 months for surviving patients, 30 patients (32%) recurred, including 5 LRs and 26 DRs. The median time to LR and DR was 36.2 months (range 14.4-65.7) and 10.4 months (range 5.2-76.9), respectively, and the 5-year local recurrence-free survival (RFS), distant RFS, and OS was 95, 71, and 76%, respectively. Local SI was performed for 90% of patients, mostly by magnetic resonance imaging (MRI; 91%). Of the five LRs, two were detected by SI and three had signs/symptoms preceding imaging. All patients underwent distant SI. Of the 26 DRs, 23 (88%) were in the lung. SI detected 22 (85%) DRs, and only 4 of 26 had signs/symptoms prompting imaging.

Conclusion: Given excellent local control with RT and radical resection for intermediate/high-grade STS of the extremity/trunk, SI of the primary site should be reserved for select patients at high risk of LR. Conversely, due to frequent occurrence of asymptomatic DR in the lungs, periodic lung SI is appropriate. Routine abdominopelvic SI may not be indicated for most histologies.