How well does O-RADS perform in a nonselected, low-risk cohort?

Researchers recently validated the diagnostic performance of O-RADS ultrasound in a nonselected cohort of 913 women, according to new work published in JAMA Network Open. 

The study yielded a malignancy rate of 8.4% for the women who presented for routine pelvic ultrasound without prior suspicion for adnexal lesions. When lesions were categorized as O-RADS 2, this rate dropped to .5% and climbed significantly in the O-RADS 5 category, at 65.6%. 

While the efficacy of the ACR’s Ovarian-Adnexal Reporting and Data System (O-RADS) ultrasound (US) has been confirmed in selected populations of women presenting with suspicion of adnexal lesions, less is known about the system’s utility in nonselected populations. A concern with this is that selected populations of women have higher instances of malignancy, which experts worry could impact the diagnostic performance of the scoring system.  

Pertaining to previous studies, corresponding author Priyanka Jha, MBBS, of the University of California, San Francisco, and co-authors of the latest research write: “Both the population demographics and the ultrasonography performance are not reflective of clinical practice patterns of many radiology departments in the United States, where women presenting for ultrasonography examinations may not have a known adnexal lesion. When an adnexal lesion is detected, the majority will have benign features, and only lesions with suspicious features will be referred to surgery. As such, the frequency of ovarian cancer in the population of women presenting to radiology is much lower than in a cohort of women being referred to surgery.”