Exploring the Utility of Optoacoustic Imaging in Differentiation of Benign and Malignant Breast Masses: Gen 2 Study

Rationale and Objectives: The combination of functional biologic data and imaging appearance has the potential to add diagnostic information to help the radiologist evaluate breast masses in an efficient, effective, and cost-conscious manner. This is the first clinical evaluation of the Gen 2(Model 9100, 8101) Imagio® System to assess image quality with both the stand-alone internal ultrasound (IUS), ultrasound-only transducer, and the Optoacoustic/Ultrasound (OA/US) duplex probe (1,2). This study assesses palpable and non-palpable breast abnormalities in patients who are referred for diagnostic breast ultrasound work-up. This study is intended to confirm the clinical acceptability of modifications made to the Imagio® System ultrasound component following Premarket Approval (PMA) of the Imagio® Gen 1 version. Materials and Methods: This prospective, single-arm, non-randomized study included 38 patients presenting with a palpable lump and/or imaging abnormality detected at a single investigational site. Each patient had the breast, and if indicated, the axillary lymph nodes imaged with the Gen 2 Imagio® system. Results: For patients with SenoGram®-predicted Likelihood of Malignancy (LOM) and pathology available (N = 23), observed sensitivity was 100.0% (9/9) with a confidence interval of (66.4%, 100.0%), using a SenoGram®-predicted False Negative Rate (FNR) cut-off of ≤ 2%. Observed specificity was 64.3% (9/14) (Confidence Interval: 35.1%, 87.2%), using a SenoGram®-predicted FNR cut-off of ≤ 2%. At 98% fixed sensitivity, the specificity (fSp) for OA/US + SG was 100.0% while it was 0.0% for IUS. The absolute gain in fSp was 100.0%. Conclusion: Combining structure with morphology can increase specificity without decreasing sensitivity in a real-world setting.