MRI surveillance for local recurrence in extremity soft tissue sarcoma

Introduction: The role of MRI in surveillance for local recurrence (LR) remains uncertain in extremity soft tissue sarcoma (STS). The aims of this study were 1) to examine the usefulness of MRI in detecting LR, 2) to identify the characteristics of LR detected by MRI, and 3) to examine whether MRI surveillance is associated with oncologic outcome. Materials and Methods: 477 patients who had regular surveillance for LR after surgery for extremity STS were reviewed. Surveillance was performed by routine MRI in 325 patients or other imaging modalities in 152 patients. Results: The rate of MRI-detected LR, defined as clinically undetectable LR identified on MRI, was 10.5% in the MRI surveillance cohort. The detection rates of MRI-detected LR were significantly higher in the patients with high risk of LR. MRI-detected LRs were more commonly located in the thigh or buttock (p = 0.005), were smaller (p = 0.001) and had LRs without mass formation (p = 0.007) than non-MRI-detected LRs. On Kaplan-Meier analysis, patients with MRI-detected LR tended to have better post-LR survival (p = 0.104). Conclusion: Routine MRI surveillance can detect a significant number of clinically undetectable LRs in extremity STS especially for LRs in the thigh or buttock, small LRs or LRs without mass formation. (C) 2018 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.