In this session, Veronica Girardi, MD, and colleagues from the Institute of Radiology at the Policlinico G.B. Rossi in Verona, Italy, will present findings from their study of 154 nonpalpable lesions found by breast MRI and missed by mammography or ultrasound.
Girardi's team found that of these lesions, targeted second-look ultrasound found 97 (63%). Targeted ultrasound's detection rate was higher for mass-like MRI lesions than nonmass MRI lesions, at 68% and 38%, respectively, with lesion size greater than 10 mm at 71% and less than 10 mm at 58%.
Of the 154 MRI-detected lesions, 111 were biopsied, either by ultrasound, MRI, or surgery. Of the 154 lesions, 42 were malignant for a true-positive rate of 27%. Ultrasound found 20 of these cancers, while the remaining 22 had no ultrasound correlate and were diagnosed by MRI or surgery.
With a relatively low true-positive rate, it's prudent to biopsy incidental MRI findings -- and using targeted ultrasound to do so is a reliable and economic tool, the team concluded.