“When a word has many meanings, it has no meaning at all”. (Anonymous)
Let’s face it: ovarian lesions seen on ultrasound can be some of the most challenging to assess and describe. When not a simple cyst, generic terms such as “complex” are commonly used providing limited insight to the provider and patient regarding the level of concern for risk of malignancy. For instance, shown here are 3 different lesions that could all be described as “complex” or “heterogeneous”, yet range from nonneoplastic to malignant.
Compound the ambiguity of nonspecific descriptors in the imaging report with the angst of possibly missing an ovarian cancer, a rare but deadly disease, and the result is “over treatment”. Too often, surgery or additional imaging are performed for physiologic and benign findings with the added unintended consequences of associated morbidity and patient anxiety.
Enter O-RADS, an acronym for the Ovarian/Adnexal Reporting and Data System.
Similar to other American College of Radiology (ACR) “RADS” systems (ie, BI-RADS for breast imaging), O-RADS gets everyone speaking the same language AND provides a risk of malignancy using a numeric scale of 0 to 5 (Table 1).
In O-RADS, there are two arms: 1) ultrasound (US), the primary imaging modality for the adnexa used by practitioners from many disciplines; and 2) magnetic resonance imaging (MRI), considered a problem-solving tool for radiologists. With O-RADS ultrasound, management guidance is also provided on triaging lesions to follow-up (clinical or imaging surveillance), additional characterization (by a specialist in US or with an MRI exam), or surgery. For the latter group, this is further divided into those lesions that can be excised by a general gynecologist, and those best managed by a gynecologic-oncologist, an important factor in improving long-term survival in the setting of ovarian malignancy.
Using the available descriptors in the O-RADS lexicon and an algorithmic approach, characterizing adnexal lesions is simplified. First, determine whether a finding in a menstruating patient meets criteria for a physiologic finding (follicle or corpus luteum). If it does not, or the patient is postmenopausal, assess for a “classic benign lesion”, a phrase coined for fairly common lesions that are almost certainly benign when typical features are seen (hemorrhagic cyst, endometrioma, dermoid cyst, paraovarian cyst, hydrosalpinx or peritoneal inclusion cyst). The remainder of lesions are assigned to 1 of 5 categories based on their solid or cystic appearance, and if cystic, the presence of septations and solid components as follows: solid lesion, unilocular cystic ± solid component(s), multilocular cystic ± solid component(s). Subsequently, features such as degree of internal vascularity, lesion size, ascites, and peritoneal nodules may come into play.
To score a lesion, color-coded O-RADS risk stratification tables are readily available and a useful resource. I personally find the O-RADS smartphone app to be an efficient and handy tool to quickly obtain a score and management recommendations. On average, I can reach a score in under 30 seconds and all the information I need for the imaging report is literally at my fingertips.
Since we started using O-RADS, our referring clinicians are asking for an O-RADS score whenever we describe an adnexal lesion as it gives them so much more useful information to counsel their patients. For instance, the patient in figure 1 with a hemorrhagic cyst did not require any imaging follow-up, the patient in figure 2 with a dermoid cyst has safely elected to undergo US surveillance in 1 year, and the patient in figure 3 with endometrioid cancer is doing well under the care of her gynecologic-oncologist.
For me, replacing vague terms (with many meanings) with standardized reporting systems not only makes sense, it’s truly meaningful.
- Strachowski, LM, et al. O-RADS for ultrasound: a user’s guide, from the AJR special series on radiology reporting and data systems. Am J Roentgenology 2021; 216:1150–1165.
- Andreotti, RF, Timmerman, D, Strachowski, LM, et al. O-RADS US risk stratification and management system: a consensus guideline from the ACR Ovarian-Adnexal Reporting and Data System Committee. Radiology 2020; 294:168–185.
- On-demand webinar available on the AIUM Online Learning Center: New Approaches to Adnexal Mass Evaluation in North America: The Use of IOTA and O-RADS Systems
Dr. Lori Strachowski is a Clinical Professor of Radiology at the University of California, San Francisco, where she holds an adjunct title in the department of Obstetrics, Gynecology and Reproductive Sciences. She is a member of the ACR O-RADS committee serving on the steering committee and chairs the education committee for O-RADS US.