TO STUDY AND ASSESS THE VALIDITY OF THE RISK OF MALIGNANCY INDEX(RMI-4) IN DISCRIMINATING BETWEEN BENIGN AND MALIGNANT OVARIAN MASSES
Authors: Keerthi B. , Parthasarathi Reddy G. , Bhuvaneswari S. , Pavani N. 
Published: April 2023

Introduction:The most fatal of all gynecological cancers is ovarian cancer. Of all gynecological cancers, it has the greatest fatality-to-case ratio. It is the 4th most prevalent cancer among women. The lifetime risk of being diagnosed with ovarian carcinoma is 1% to 1.5 %, with a nearly 0.5% chance of dying from it. Suboptimal primary cytoreductive surgery has great prognostic significance. The reason was because of inappropriate preoperative evaluation, which decides the kind of surgery being performed and the surgeons expertise of the surgeon in performing staging laparotomy if indicated. Hence, a gynecologist must be able to differentiate benign from the malignant ovarian mass. Several studies have revealed that the diagnosis of ovarian mass by investigations like Ultrasonogram, Doppler, MRI, CT has been proved to be uncertain despite the need for expertise. The goal of this study was to assess the ability of the Risk of Malignancy Index Scoring System (RMI- 4) in differentiating benign from malignant ovarian masses and to compare the scoring patterns to histopathological findings. Objectives: To validate the efficiency of the Risk of Malignancy Index(RMI-4) in discriminating benign and malignant ovarian tumors.To correlate the calculated value of the Risk of Malignancy Index(RMI-4) to the histopathological report.To evaluate the performance of individual parameters and the Risk of Malignancy Index(RMI-4) in differentiating benign and malignant ovarian tumors. Materials and methods: A prospective observational study in one year from date of approval from institutional ethical committee i. e from 2019 to 2021on women attending Gynecology outpatient and inpatient department diagnosed with an ovarian mass at Government Maternity Hospital, Tirupati. Results : 50 women with ovarian mass were selected for the study. Patients with endometriosis, fibroid uterus, Pelvic inflammatory disease, menstruation, pregnancy, ectopic pregnancy, and other non-gynecological conditions like peritonitis, diverticulitis, inflammatory bowel disease, tuberculosis, liver disease, recent surgery, are excluded. General and gynecological examinations were done for all cases. Ultrasound pelvis was done for all the patients and the presence of bilateral ovarian mass, multiloculated tumor, presence of solid areas, ascites, and extra ovarian metastasis was noted. An ultrasound score (U) of 1 was given if none or one of the features are found, and a score of 4 was given if two or more of these features were noted. Size of the tumor measured. A score of 1 was given for a tumor less than 7 cm and a score of 2 for a tumor size more than or equal to 7 cm size. Postmenopausal status was defined as more than one year of amenorrhea or age older than 50 years for women who had undergone hysterectomy they were scored as M=4. All other patients who did not meet these criteria were defined in a premenopausal status which scored M=1. The Risk of Malignancy Index (RMI-4) was calculated by using the formula: RMI-4 = U x M x S x CA 125. Laparotomy was done for all cases and the specimen was sent for histopathological examination which is the gold standard.90% of the tumors were benign and 10% were malignant.Prediction of malignancy by CA 125, ultrasound, and RMI-4 was analyzed.The optimal cut-off value of RMI-4 was 450 with a sensitivity of 95.56%, specificity of 100%, PPV of 100%, and NPV of 71.43%.Though the Specificity and PPV of CA125 were high, Sensitivity was less (86.67%).This study showed that RMI-4 had better performance than CA 125, USG score, and menopausal score in predicting malignancy. Conclusion:RMI-4 is a multimodal approach that is simple and easily applicable in the preoperative evaluation of a patient with an ovarian mass.Risk of Malignancy Index -4 (RMI-4) is a reliable method in discriminating benign and malignant ovarian mass preoperatively.Risk of Malignancy Index -4 (RMI-4) is a better scoring index in differentiating benign and malignant ovarian mass when compared to individual tests of ultrasonogram or CA125 level.The optimal cut-off point of Risk of Malignancy Index -4 (RMI-4) at which benign and malignant tumors can be discriminated was 450 in the present study.RMI-4 is the most useful scoring system in the proper selection of patient.Since the specificity of Risk of Malignancy Index -4 (RMI-4) was high, there is a potential role for this index in the selection of cases for conservative management or minimally invasive surgery in case of benign ovarian masses.