Objective: To determine clinical role of risk malignancy index to differentiate between benign and malignant ovarian masses.
Material and Methods: A prospective study was carried out in 40 women with ovarian mass in the Department of Gynecology, LTMMC, Maharashtra, India between February 2013 to October 2014. The profile of these patients was recorded in a predesigned proforma. Ultrasound, serum CA-125 level and menopausal scoring was done as a part of RMI calculation. Histopathology reports were later analyzed for final correlation with ultrasound findings, serum CA-125 level and menopausal status separately and RMI-1 and RMI-2 in combination.
Results: Both RMI-1 and RMI-2 have shown the ability of correctly identifying both benign and malignant ovarian mass with the arc under the curve in ROC 93.2% for RMI-1 and 90.99% for RMI-2. Both RMI-1 and RMI-2 value were significantly higher in malignant neoplasm than benign. RMI-1 had the highest sensitivity and specificity at the cut-off point 200. With the cut off value of >=200 used to diagnose malignant neoplasm, it had a sensitivity of 90.9%, specificity 94.4%,PPV 95.2% and NPV 89.5% in RMI-1 and sensitivity 90.9%, specificity 72.2%,PPV 80% and NPV 86.7% in RMI-2. Considering both RMI-1 and RMI-2 at the cut off value of 200, out of total 20 malignant cases, 2 cases of ovarian cancers were missed.
Conclusion: RMI is very useful in pre-operative diagnosis of ovarian malignancy. It overcomes the false positive result obtained while using a single parameter like serum CA-125 or USG alone.