The fifth leading cause of cancer death in women, ovarian cancer is difficult to detect, primarily because the early-stage disease is usually asymptomatic and symptoms of late-stage disease are nonspecific.
The American College of Radiology (ACR) Ovarian Adnexal Reporting and Data System (O-RADS) as a stand-alone test shows high sensitivity and negative predictive value, but poor specificity in characterizing adnexal tumors.
Grover
But specificity and diagnostic accuracy of O-RADS improves significantly with the addition of contrast-enhanced US studies, according to new research presented Wednesday by Shabnam Bhandari Grover, MD, DMRD, professor of radiology at Sharda School of Medical Sciences and Research, Sharda University, Greater Noida, India.
“Early preoperative characterization of an ovarian mass as benign or malignant is crucial for management decisions and it has been documented that patients with malignancy have a much better outcome when managed in dedicated oncology centers,” she explained.
While US is usually used to detect and diagnose adnexal tumors, MRI serves as a problem-solving tool in cases where US is inconclusive.
Dr. Grover added that US is also a more economical, widely available modality compared to MR.
Ultrasound contrast media is introduced intravenously into the vascular system as microbubbles to improve visualization. “No adverse reactions are reported to ultrasound contrast agents and the only limitation to ultrasound contrast agents is chronic lung disease as the contrast is excreted through the lungs,” she said.
Evaluating Contrast-Enhanced US with O-RADS
In her research, Dr. Grover and colleagues investigated the standalone efficacy of O-RADS compared with O-RADS combined with contrast US (using both qualitative and quantitative parameters) in characterizing ovarian masses. The reference point was gold standard histopathology from either biopsy or a surgically removed specimen.
The prospective study included 98 women with adnexal masses. Of the tumors evaluated, 36 were benign and 62 were malignant.
Results showed that while standalone O-RADS had a sensitivity of 100%, it had a specificity of just 50%, with a diagnostic accuracy of 81.6%. However, when combined with contrast-enhanced US the specificity of O-RADS increases to 91.2 % and the diagnostic accuracy improved by more than 10 points to 91.8%, while sensitivity dropped to 92.2%.
Dr. Grover said she believes hers is the first study comparing the diagnostic accuracy of O-RADS as a stand-alone test vs. its accuracy when combined with contrast-enhanced US, and the latter has been found to be more robust.
She concluded that contrast-enhanced US should be further researched for characterization of adnexal masses as a more economical option for patients.
For More Information
View the RSNA 2020 session, Evaluation of the Efficacy of ACR O-Rads as a Stand-Alone Test Versus Its Efficacy When Combined With Contrast Enhanced Ultrasound for Definitive Characterization of Adnexal Tumors — SSGU05 at RSNA2020.RSNA.org.
