The Prospective External Validation of International Ovarian Tumor Analysis (IOTA) Simple Rules in the Hands of Level I and II Examiners

Abstract

To externally validate the International Ovarian Tumor Analysis (IOTA) Simple Rules (SR) by examiners with different levels of sonographic experience defined by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) and to assess the morphological ultrasound features of the adnexal tumors classified as inconclusive based on IOTA SR. In the two-year prospective study adnexal tumors were assessed preoperatively with transvaginal ultrasound by examiners with different levels of experience (level 1- IOTA SR1, level 2-IOTA SR2). Additionally, an expert (level 3) evaluated all tumors by subjective assessment (SA). If the rules could not be applied, the tumors were considered inconclusive. The final diagnosis was based on the histopathological result of the removed mass. The diagnostic performance measures for the assessed model were sensitivity, specificity, negative (LR-) and positive(LR+) likelihood ratios, accuracy (ACC) and diagnostic odds ratio (DOR). 226 women with adnexal tumors scheduled for surgery were included in the stutdy. The prevalence of malignancy was 36.3 % in the group of all studied tumors and was 52.5 % in the inconclusive group (n = 40) (p = 0.215). Fewer tumors were classified as inconclusive by level 2 examiners compared to level 1 examiners [20 (8.8 %) vs. 40 (17.7 %); p = 0.008], resulting from the discrepancy in the evaluation of acoustic shadows and the vascularization within the tumor. For level 1 examiners a diagnostic strategy using IOTA SR1 +MA (assuming malignancy when SR inconclusive) achieved a sensitivity, specificity and DOR of 96.3 %, 81.9 %, 13.624 respectively. For level 2 examiners the diagnostic strategy for IOTA SR2 +MA achieved a sensitivity, specificity and DOR of 95.1 %, 89.6 %, 137,143, respectively. Adding SA by an expert (or level 3 examiner) when IOTA SR were not applicable improved the specificity of the test and achieved a DOR of 505.137 (SR1 +SA) and 293.627 (SR2 +SA). The SA by an expert proved to have the best diagnostic performance with a DOR of 5768.857, and a sensitivity and specificity of 97.6 % and 99.3 % respectively. Within the inconclusive group the most common tumors were unilocular-solid (n-13), solid (n-8) and multilocular-solid (n-10) ones. All multilocular tumors were classified as inconclusive because of their size (≥ 100 mm) and were found to be benign by pathology. Most of the inconclusive tumors with cystic content presented low-level (43.75 %) echogenicity, followed by ground-glass (34.37 %), mixed (12.5 %) and anechoic (9.4 %). The study results show excellent diagnostic performance of IOTA Simple Rules followed by subjective expert assessment in inconclusive tumors irrespective of the level of experience, while subjective assessment by an expert still has the highest diagnostic odds ratio. The number of inconclusive cases seems to depend on the level of ultrasound expertise and less experienced examiners have a tendency to overestimate blood flow and a presence of acoustic shadows within the tumors. IOTA SR were not...

Diagnostic accuracy and cost‐effectiveness of different strategies to triage women with adnexal masses: a prospective study

“…In our study, SR were chosen because they could easily be memorized, applied and reported without the use of a digital device, and because they have shown good performance in both oncology centers and general hospitals. In particular, we chose SR ± SA as it is an ideal approach for triaging adnexal masses in an academic hospital in which there are sonographers with varying levels of training and experience.…”

Validation of the Performance of International Ovarian Tumor Analysis (IOTA) Methods in the Diagnosis of Early Stage Ovarian Cancer in a Non-Screening Population

“…Our results might not necessarily be applicable to less experienced operators. However, published studies have shown that the IOTA SRs and ADNEX retain their performance in the hands of less experienced examiners [27,28,35,36,37,38,39,40,41]. This is likely to be true also for the SRR model, because the same ultrasound variables are used in the original SRs are used to calculate the risks of the SRR model.…”

Simple Rules, Not So Simple: The Use of International Ovarian Tumor Analysis (IOTA) Terminology and Simple Rules in Inexperienced Hands in a Prospective Multicenter Cohort Study

“…Alcazar et al found that 12 % of malignant masses were miscategorized as benign by non-expert examiners applying the simple rules [6]. Also, Knafel et al reported that as much as 50 % of their inconclusive results (20/40) were in fact due to misclassification [11].…”