Validation of ADNEX and IOTA two-step strategy and estimation of risk of complications during follow-up of adnexal masses in low-risk population

M A Pascual ¹, L Vancraeynest ^2,3, S Timmerman ^2,3

⁰Department of Obstetrics, Gynecology, and Reproduction, Hospital Universitari Dexeus, Barcelona, Spain.

Ultrasound in Obstetrics & Gynecology : the Official Journal of the International Society of Ultrasound in Obstetrics and Gynecology +

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March 13, 2024

View abstract on PubMed

Summary

The Assessment of Different NEoplasias in the adneXa (ADNEX) model and the International Ovarian Tumour Analysis (IOTA) two-step strategy accurately predict malignancy in adnexal masses. Conservative management is safe for benign adnexal masses, with a low risk of complications.

Area Of Science

Gynecologic oncology
Diagnostic imaging
Risk assessment

Background

Adnexal masses are common, and accurate malignancy prediction is crucial for appropriate management.
Distinguishing benign from malignant adnexal masses in an outpatient, low-risk setting can be challenging.
The Assessment of Different NEoplasias in the adneXa (ADNEX) model and the International Ovarian Tumour Analysis (IOTA) two-step strategy are established tools for evaluating adnexal masses.

Purpose Of The Study

To evaluate the diagnostic performance of the ADNEX model and the IOTA two-step strategy in predicting malignancy of adnexal masses in a low-risk outpatient setting.
To assess the risk of complications in benign adnexal masses managed conservatively with clinical and ultrasound follow-up.

Main Methods

Retrospective analysis of prospectively collected data from the IOTA Phase-5 study.
Validation of the ADNEX model (without CA125) and the IOTA two-step strategy using area under the receiver-operating-characteristics curve (AUC), calibration, and classification metrics.
Evaluation of the 5-year cumulative incidence of complications (spontaneous resolution, torsion, cyst rupture, borderline tumors, invasive malignancy) in conservatively managed benign masses.

Main Results

Both the ADNEX model (AUC 0.95) and the IOTA two-step strategy (AUC 0.94) demonstrated high accuracy in distinguishing benign from malignant adnexal masses.
The IOTA two-step strategy showed better clinical utility at malignancy risk thresholds below 3%.
In conservatively managed benign masses, the 5-year cumulative incidence of spontaneous resolution was 66%, with a very low incidence of complications such as torsion (0%), cyst rupture (0.1%), borderline tumors (0.2%), and invasive malignancy (0.2%).

Conclusions

The ADNEX model and IOTA two-step strategy are effective tools for predicting malignancy in adnexal masses within a low-risk population.
Conservative management of adnexal masses with benign ultrasound characteristics is safe and associated with a low risk of significant complications.

Keywords:

ADNEX IOTA two‐step strategy adnexal lesion ovarian cancer ultrasound