Is Doppler ultrasound a feasible and accurate tool for screening of malignant soft tissue tumor? -Validation study of 189 pathologically proven cases
Objectives The utility of ultrasound imaging in the screening of soft-part tumours (SPTs) has been reported. We classified SPTs according to their blood flow pattern on Doppler ultrasound and re-evaluated the efficacy of this imaging modality as a screening method. Additionally, we combined Doppler ultrasound with several values to improve the diagnostic efficacy and establish a new diagnostic tool.
Methods This study included 189 cases of pathologically confirmed SPTs (122 cases of benign disease including SPTs and tumour-like lesions and 67 cases of malignant SPTs).Ultrasound imaging included evaluation of vascularity by colour Doppler. We established a scoring system to more effectively differentiate malignant from benign SPTs (ultrasound-based sarcoma screening [USS] score).
Results The mean scores in the benign and malignant groups were 1.47±0.93 and 3.42±1.30, respectively. Patients with malignant masses showed significantly higher USS scores than did those with benign masses (p<1×10-10). The area under the curve was 0.88 by receiver operating characteristic (ROC) analysis, which was larger than that of the Doppler classification described by Giovagnorio et al (0.77). Based on the cutoff value (3 points) calculated by ROC curve analysis, the sensitivity and specificity for a diagnosis of malignant SPT was 85.1% and 86.9%, respectively.
Conclusions Assessment of vascularity by Doppler ultrasound alone proved to be insufficient for differentiation between benign and malignant SPTs. Preoperative diagnosis of most SPTs is possible by combining our USS score with characteristic clinical findings and MRI findings.