Effectiveness Of Risk Of Malignancy Index (Rmi) To Differentiate Benign From Malignant Ovarian Masses – A Cross Sectional Study

Abstract

Introduction: Diagnostic dilemma exists in differentiating benign from malignant ovarian lesions making treatment difficult. CA125, USG scoring have been used for differentiating these lesions, however significant overlap exist in these test. RMI is a simple, cost-effective method that can be used by gynecologist even at less specialized center to differentiate malignant from benign ovarian masses. Material& Methods: One year cross sectional study involving ovarian lesions on sonography were analysed in KLE’s Dr P.K hospital & MRC in Belgaum. During the study 74 women satisfied the selection criteria, however 10 women were not operated hence only 64 cases were finally analysed . RMI was calculated by combining USG score, CA125 and Menopausal status i.e. (RMI = U×CA125 ×M) where cut-off value of ≥200 as malignant and finally compared with gold standard HPR . Statistical analysis: Sensitivity, specificity, positive and negative predictive value was calculated to predict the effectiveness of the RMI. Results: Out of 64 cases analysed 20 had RMI of ≥200 of which 14 cases were malignant and 6 were benign on HPR. And 44 cases who had RMI <200 out of which only 1 turned out to malignant on HPR. The sensitivity is 93.3%, specificity is 87.7%, PPV is 70%, and NPV is 97.7%. Conclusions: The RMI was accurate in differentiating benign from malignant ovarian lesions in majority of the cases. Since the RMI is high there is also a potential role in selection of cases for conservative management or minimal invasive surgery.