The efficacy of diagnostic imaging for superficial soft tissue masses on a community level.

Abstract

e23547 Background: Ultrasound and magnetic resonance imaging (MRI) have both demonstrated high sensitivity and specificity in the diagnosis of soft tissue masses in previous studies. However, there may be a lack of generalizability of these findings to community healthcare settings. We seek to identify the efficacy of two of the most common forms of diagnostics in cases of superficial soft tissue masses, ultrasound and MRI, as well as report the rate of implementation of diagnostic imaging at a community level. Methods: A retrospective chart review was conducted with 343 patients meeting inclusion criteria over a period of 2 years. Data was collected and organized into the various forms of diagnostic workups performed. Diagnostic accuracy was assessed by comparing ultrasound and MRI findings to pathology results, the established gold standard. Results: 56.9% (n=195) of all masses were operated on without ultrasound or MRI, with 6.2%(n=12) being malignant. Of these malignant cases, 58.3% (n=7) of them underwent surgical excision without other forms of diagnostic workup (e.g. CT, pre-surgical biopsy). Among 22 malignant masses evaluated by ultrasound, only 4.5% (n=1) was correctly identified as malignant, while 45.5% (n=10) were incorrectly characterized, and 45.5% (n=10) yielded inconclusive results. In contrast, of 88 benign masses assessed by ultrasound, 81.2% (n=72) were correctly identified, 6.8% (n=6) were incorrectly characterized, and 10.2% (n=9) had inconclusive findings. 8.8% (n=10) went on to be confirmed by MRI despite a correct diagnosis. MRI demonstrated superior accuracy in malignant mass detection, correctly identifying 67.7% (n=21) of 31 malignant cases, with 12.9% (n=4) incorrect characterizations and 19.4% (n=6) inconclusive results. For benign masses, MRI correctly identified 79.4% (n=27) of 34 cases, with 5.9% (n=2) incorrect characterizations and 14.7% (n=5) inconclusive findings. See table for diagnostic performance results. Conclusions: These findings reveal a discrepancy between the ultrasound performance demonstrated in recent studies and its performance at a community level, especially its sensitivity for malignant masses. Due to its low screening ability, 40.9% (n=45) being unable to replace the need for MRI, and the heterogeneity of diagnostic workups performed, there is a need for development of a uniform protocol in the work-up for community healthcare systems. Diagnostic performance of ultrasound and MRI for superficial soft tissue masses. Ultrasound MRI Benign Sensitivity 92.3% (CI 84.0-97.1%) 93.1% (CI 77.2-99.15%) Specificity 9.1% (CI 0.2-41.28%) 84% (CI 63.9-95.5%) Malignant Sensitivity 9.1% (CI 0.2-41.28%) 84% (CI 63.9-95.5%) Specificity 100% (CI 95.1-100%) 96.4% (CI 81.7-99.9%)