Comparison of 4 Risk-of-Malignancy Indexes in the Preoperative Evaluation of Patients With Pelvic Masses: A Prospective Study

BackgroundThe aim of this study was to validate the risk-of-malignancy index (RMI) incorporating menopausal status, serum CA 125 levels, and imaging findings for discriminating benign from malignant pelvic masses and to evaluate the ability of 4 different RMIs.Patients and MethodsThis is a prospective study of 296 women admitted to the Department of Obstetrics and Gynecology of Kochi Health Sciences Center, between September 2011 and April 2014, for surgical exploration of pelvic masses. The RMI 1, 2, 3, and 4 methods were calculated for all patients together with the sensitivity, specificity, positive predictive value, and negative predictive value.ResultsThe sensitivity of RMIs 1, 2, 3, and 4 was 73.0%, 81.1%, 73.0%, and 77.0%, respectively, and the specificity was 93.7%, 89.6%, 93.7%, and 92.3%, respectively. The RMI 2 was significantly better at predicting malignancy than RMIs 1 3; however, there was no statistically significant difference in performance of RMIs 2 4.ConclusionThe RMI method is a valuable and applicable method in diagnosing pelvic masses with high risk of malignancy and a simple technique that can be used in gynecology clinics and less-specialized centers.