A Study on Evaluation of Diagnostic Accuracy of Risk of Malignancy Index in Preoperative Assessment of Ovarian Tumors in Tertiary Care Centre

INTRODUCTION: The discrimination between benign and malignant adnexal masses is central to decisions regarding clinical management and surgical planning for such patients. A standardized method for preoperative identification of probable malignant masses would allow optimization of first line of treatment for women with ovarian cancer. OBJECTIVE: The Aim of the study was to evaluate the diagnostic accuracy of Risk of Malignancy Index in preoperative discrimination between benign and malignant ovarian masses. Study Design: Prospective observational study. MATERIALS AND METHODS: This prospective observational study was conducted in the Department of Obstetrics and Gynaecology, Thanjavur Medical College and Hospital, Thanjavur from January 2019 – January 2020 with a sample size of 100 cases with clinical diagnosis of ovarian tumors admitted for surgery. Obtained data from patient details were age, gravidity, parity, menopause status, ultrasound findings and CA 125 levels. For all patients ultrasound scans were performed. For the assessment of Risk of Malignancy (RMI) Jacob’s model was used. Histopathological results of all patients were recorded postoperatively. Malignancy status of the surgically removed adnexal mass was the gold standard. RMI was calculated by combining USG score, CA 125 and Menopausal status (i.e.,) RMI=U×CA 125 ×M. Sensitivity, Specificity, Positive predictive value and Negative predictive value of individual parameters were calculated and compared with the validity of RMI to predict the effectiveness of the RMI. RESULTS: In our study one hundred women with adnexal masses were included. Eighty two women had benign ovarian masses while, malignant ovarian tumor were found in 18 women. Most common benign tumor was serous cyst adenoma and most common malignant tumor was serous cystadeno carcinoma. Analysing the diagnostic performance of RMI, we found that RMI performed better than individual parameters in differentiating benign and malignant tumors at the cut of score 250. The present study gives 250 as the best cut off point for RMI to differentiate benign and malignant ovarian masses with a sensitivity of 66.67% and specificity of 92.68%. CONCLUSION: RMI is highly reliable and valuable in differentiating benign and malignant tumors which can be used by the general gynaecologists at the periphery for referral of suspected ovarian tumors to oncology centers, thus improving the survival and prognosis of women undergoing surgery for ovarian tumors