Differential diagnosis of adnexal masses : A sequential use of the Risk of Malignancy Index and a novel computer aided diagnostic tool.

BACKGROUND: Accurate preoperative assessment of adnexal masses permits appropriate triage of malignant tumours to gynaecological oncologists in cancer centres while allowing benign lesions to be managed by general gynaecologists. The Risk of Malignancy Index (RMI) is routinely used for triaging women with adnexal masses. OBJECTIVES: This paper evaluates the value of Ovarian HistoScanning, a novel computerised technique to interpret ultrasound data, in improving triage of women with adnexal masses. METHODS: RMI indices were assessed in 199 women enrolled in a prospective HistoScanning study. Ultrasound scores were obtained by blinded analysis of archived images. The following sequential test was developed: HistoScanning was modelled as a second-line test for RMI between a lower cut-off and an upper cut-off. The optimal combination of these cut-offs that together maximized the Youden index (Sensitivity + Specificity -1) was determined. RESULTS: Using RMI at the standard cut-off value of 250 resulted in a sensitivity of 74% and a specificity of 86%. When RMI was combined with HistoScanning, the highest accuracy was achieved by using HistoScanning as a sequential second-line test for patients with RMI values between 105 and 2100. At these cut-off values, sequential use of RMI and HistoScanning resulted in mean sensitivity and specificity estimates of 88% and 95%, respectively. CONCLUSIONS: Our data suggest that HistoScanning may have the potential to improve the diagnostic accuracy of RMI, which could result in a better triage of women with adnexal masses. Further prospective validation is warranted. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.