Multicentre external validation of IOTA prediction models and RMI by operators with varied training

Abstract

Background:Correct characterisation of ovarian tumours is critical to optimise patient care. The purpose of this study is to evaluate the diagnostic performance of the International Ovarian Tumour Analysis (IOTA) logistic regression model (LR2), ultrasound Simple Rules (SR), the Risk of Malignancy Index (RMI) and subjective assessment (SA) for preoperative characterisation of adnexal masses, when ultrasonography is performed by examiners with different background training and experience.Methods:A 2-year prospective multicentre cross-sectional study. Thirty-five level II ultrasound examiners contributed in three UK hospitals. Transvaginal ultrasonography was performed using a standardised approach. The final outcome was the surgical findings and histological diagnosis. To characterise the adnexal masses, the six-variable prediction model (LR2) with a cutoff of 0.1, the RMI with cutoff of 200, ten SR (five rules for malignancy and five rules for benignity) and SA were applied. The area under the curves (AUCs) for performance of LR2 and RMI were calculated. Diagnostic performance measures for all models assessed were sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR−), and the diagnostic odds ratio (DOR).Results:Nine-hundred and sixty-two women with adnexal masses underwent transvaginal ultrasonography, whereas 255 had surgery. Prevalence of malignancy was 29% (49 primary invasive epithelial ovarian cancers, 18 borderline ovarian tumours, and 7 metastatic tumours). The AUCs for LR2 and RMI for all masses were 0.94 (95% confidence interval (CI): 0.89–0.97) and 0.90 (95% CI: 0.83–0.94), respectively. In premenopausal women, LR2−RMI difference was 0.09 (95% CI: 0.03–0.15) compared with −0.02 (95% CI: −0.08 to 0.04) in postmenopausal women. For all masses, the DORs for LR2, RMI, SR+SA (using SA when SR inapplicable), SR+MA (assuming malignancy when SR inapplicable), and SA were 62 (95% CI: 27–142), 43 (95% CI: 19–97), 109 (95% CI: 44–274), 66 (95% CI: 27–158), and 70 (95% CI: 30–163), respectively.Conclusion:Overall, the test performance of IOTA prediction models and rules as well as the RMI was maintained in examiners with varying levels of training and experience.

Role of a Risk of Malignancy Index in Clinical Approaches to Adnexal Masses

“…In our study we found sensitivity 73.5%, specificity 97.1%, PPV 95.3% and NPV 82% by using RMI of more than 200. In the literature different values were defined for RMI and our results confirmed these studies (Jacobs et al, 1990;Davies et al, 1993;Tingulstad et al, 1999;Manjunath et al, 2001;Anderson et al, 2003;Ma et al, 2003;Obeidat et al, 2004;Yamamoto et al, 2009;Van der Akker et al, 2010;Ashrafgangooei et al, 2011;Van Gorp et al, 2012;Sayasneh et al, 2013;Terzic et al, 2013;Arun-Muthuvel et al, 2014).…”

Performance of the Risk of Malignancy Index for Discriminating Malignant Tumors in Women With Adnexal Masses

“…Patients presenting with at least 1 adnexal mass were eligible for inclusion in the study, and when there was more than 1 mass, the mass with the most complex morphologic characteristics or, in cases of similar morphologic characteristics, the largest one was considered for statistical analysis, as suggested by Sayasneh et al 23 More than 1 adnexal mass was detected in 20 women.…”

Simple descriptors and simple rules of the International Ovarian Tumor Analysis (IOTA) Group: a prospective study of combined use for the description of adnexal masses

“…There are several studies that validate classification models for adnexal formations; the best results are obtained using the simple Rules and the Logistic Regression 2 (LR2) model, as well as the IOTA group [24], with different levels of expertise [25]. Offline teaching based on 3D volumes for beginners in gynecologic ultrasound shows good results [26].…”