The accuracy of a novel sonographic scanning and reporting protocol to survey for soft tissue sarcoma local recurrence.

ABSTRACT

OBJECTIVE: This study aims to determine the accuracy of a novel ultrasonography (US) scanning and reporting protocol to detect recurrences. The secondary aim is to compare US and MRI accuracy and agreement. MATERIALS AND METHODS: In this IRB-approved prospective study, consecutive patients presenting for MRI surveillance after resection were enrolled and underwent same-day US. Blinded to clinical information and the MRI, the US scanner characterized lesions using a proposed novel lexicon. Outcome was defined either by histology or a subsequent MRI scan confirming the presence or absence of recurrence. Fisher's exact test and Kappa test were performed to assess of the significance and agreement between US, MRI, and outcome. RESULTS: A total of 68 US scans were performed on 55 patients. The overall accuracy to diagnose recurrence was the same for US and MRI (92.6%) while US was less sensitive (75.0% vs. 91.7%) but more specific (97.6% vs. 92.9%) than MRI. The two lesions missed by US but not MRI were an entirely intraosseous metastasis and a subcentimeter skin nodule. There was strong agreement between US and MRI with outcome (k = 0.787 and 0.801, respectively). CONCLUSIONS: These pilot data suggest the accuracy of this novel US local recurrence surveillance method is comparable to MRI. A multi-institutional prospective trial would increase power and determine reproducibility.