Introduction/Background To externally validate the Assessment of Different NEoplasias in the adneXa (ADNEX) model and evaluate its performance in differentiating benign from malignant adnexal masses. This study aimed to assess the diagnostic accuracy of the ADNEX model in a tertiary center in Greece.

Methodology A retrospective analysis of prospectively collected single-center university hospital data was performed from 2019 to 2022 by non-expert, although IOTA (International Ovarian Tumor Analysis Group) certified, sonographers. All patients were examined by transvaginal and transabdominal ultrasonography. Serum CA125 levels were measured and the diagnostic performance of the ADNEX model was assessed with CA125 as a predictor.

Results We retrieved data from 95 patients with 97 adnexal masses, of which 29 were excluded based on IOTA Simple Descriptors (SD) and Simple Rules (SR). Of the 66 inconclusive cases with 68 adnexal masses referred to the gynecologic oncology center, 11/66 (16.7%) were benign and 55/66 (83.3%) were malignant tumors. Postoperative histopathology confirmed 9/11 (81.8%) benign adnexal masses, whereas 2/11 (17.2%), following extensive consultation, were assigned to long-term follow-up. The Area Under the ROC (receiver operating characteristic) curve (AUC) for the distinction between benign and malignant tumors was 0.76, sensitivity was 100% (95% CI: 92.1–100) and specificity was 52.4% (95%CI: 29.8–74.3). False positive rate (FPR) was 47.6% and negative predictive value (NPV) was 100%. The most accurate staging of malignancy was observed for Stage II-IV ovarian cancer (29 histopathology vs. 31 ADNEX), whereas the less accurate staging was observed for borderline (2 histopathology vs. 15 ADNEX) and Stage I ovarian cancer (0 histologypathology vs. 3 ADNEX).

Conclusion Our findings suggest that, when used by non-experts, IOTA certified sonographers, the ADNEX model tends to overestimate the probability of borderline and stage I malignant adnexal masses. The aforementioned accurately reflect the weaknesses of medical training and health care system in Greece.

Disclosures None.