Abstract P4-02-08: Opto-acoustic imaging of the breast: Downclassification and upclassification of suspicious breast masses

Abstract

Abstract Background Imagio® is an opto-acoustic (OA) breast imaging system designed to concomitantly collect OA images together with diagnostic ultrasound (CDU). The device is intended to improve distinction between benign and malignant masses. In this interim analysis of the post-market surveillance MAESTRO study we report the results of 75 patients who had breast masses classified as BI-RADS 4a and 4b by CDU. Aim We assessed OA's sensitivity, specificity, and its ability to downgrade benign masses and upgrade malignant masses based on the probability of malignancy (POM) and BI-RADS category. Methods Seventy-five patients with 78 breast masses were evaluated with OA prior to biopsy. For each mass, the radiologist scored 5 OA features, assigned a POM and BI-RADS category. OA sensitivity, specificity, and BI-RADS downgrade and upgrade percentages were assessed with and without contribution from a previously derived nomogram. Results The mean POM difference between malignant and benign masses was higher for OA (37%) than for CDU (27%). OA specificity was 43% without the nomogram and 68% with the nomogram. OA sensitivity was 97% with and without the nomogram. With OA 43% of benign masses could be downgraded and 47% of malignant masses could be upgraded in BIRADS category. Conclusion These results appear to confirm the previously reported ability of OA to improve the differentiation between benign and malignant masses compared to CDU alone, to potentially decrease negative biopsies, and to upgrade BI-RADS category in malignant masses. The MAESTRO study (n=200) may further confirm these results. Citation Format: Menezes GLG, Pijnappel RM, Meeuwis C, Bisschops B, Veltman J, Lavin PT, Mann RM. Opto-acoustic imaging of the breast: Downclassification and upclassification of suspicious breast masses [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-02-08.