Improving the performance of IOTA simple rules: sonographic assessment of adnexal masses with resource-effective use of a magnetic resonance scoring (ADNEX MR scoring system)

Purpose To compare the International Ovarian Tumor Analysis (IOTA) simple rules, simple rules risk ultrasound models, alone or in combination with magnetic resonance (MR) score to predict malignancy in women with adnexal masses. Methods 171 women with adnexal masses were included from February 2014 to February 2016. 120 women had histopathological diagnosis obtained from surgery or percutaneous biopsy. The other 51 women were submitted to surveillance with ultrasound (US) for at least 1 year. Patients were examined with US and MR. US reports were rendered using IOTA systems. We compared five diagnostic approaches, aimed at diagnosing women with malignant tumors among those with adnexal masses: We calculated the performance and net benefits (decision curve analysis) for five distinct diagnostic approaches: (1) US simple rules (SR), (2) simple rules risk score (SRRisk), (3) US SR followed by subjective assessment (SA) of indeterminate cases, (4) SR followed by MR score for the indeterminate cases, and (5) MR score for all women. Results The MR score for all patients was the approach that yielded the best-standardized net benefit regardless of the risk threshold. However, referring women with indeterminate masses on SR to MR score yielded the second-best net benefit. Conclusion Although this study leaves no doubt about the superiority of MR score over US-based methods for the discrimination of malignant tumors in women with adnexal masses, restricting the use of MR score only to women with indeterminate masses on US SR is a safe, appropriate way to triage women with adnexal masses.