Abstract CT230: A prospective, multi-center, randomized, double-arm trial to determine the impact of the Perimeter B-Series OCT System on positive margin rates in breast conservation surgery

Abstract Background: Optical coherence tomography (OCT) is a high-resolution tissue-imaging modality that enables real-time imaging up to 2mm deep. The Perimeter B-Series OCT System combines wide field-OCT (WF-OCT) with an artificial intelligence system, ImgAssist, to assist clinicians in the detection of lesions suspicious for breast cancer. The objective of this investigational device trial is to assess adjunctive Perimeter B-Series OCT System use compared to standard care in identifying and addressing positive margins intraoperatively. Design: Prospective, multicenter, randomized, double-arm trial in females with biopsy-confirmed cancer undergoing breast conservation surgery (BCS) (NCT05113927). Following lumpectomy and standard-of-care intraoperative margin assessment participants will be randomized to a device or control arm (2:1 schema). Controls may undergo intraoperative pathology or frozen section analysis, per routine. WF-OCT will be done on all device arm specimens, with an opportunity to excise tissue from the lumpectomy cavity post-analysis. The new margin will be imaged with WF-OCT and the surgeon may take up to a maximum of 6 total shaves, including up to 2 shaves in each orientation. Eligibility: Adult females undergoing breast conservation surgery for biopsy-confirmed Stage 0-III invasive ductal and/or DCIS are eligible, including post-neoadjuvant therapy. Pregnant or lactating, those with Stage IV cancer, lobular carcinoma as primary diagnosis, previous ipsilateral breast surgery, multi-centric or bilateral disease, use of cryolocalization, or any treatment affecting margin integrity will be excluded. Specific Aim: The study hypothesis is that use of the Perimeter B-Series OCT System in BCS will reduce the proportion of subjects with at least 1 unaddressed positive margin. The primary endpoint is occurrence of aat least 1 unaddressed positive margin for a subject. The secondary endpoint is the number of unaddressed positive margins per subject. Safety includes Adverse Events; false-positive shaves per subject (device arm); and BREAST-Q Satisfaction with Breasts subscale. Other outcomes are total excised tissue volume, initial and all procedures including repeat surgeries; margin-level effectiveness (sensitivity, specificity, NPV and PPV); and operative time. Statistical Methods: The study was powered via the primary endpoint, assuming a 15% unaddressed margin rate, 90% power, 2:1 device-to-control ratio, and 10% loss of subjects due to screen or device failure. Both the primary and secondary effectiveness endpoints are based on within-subject comparison of the 2 treatments in the device arm (SOC+WF-OCT). Planned Accrual: 309 subjects (206 device, 103 control) will be enrolled at 8 centers over approximately 12 months. Citation Format: David Rempel, Andrew Berkeley, David Moos, Allison A. DiPasquale, Maryam Elmi, Richard E. Fine, Marie Lee, Bridget O’Brien, John F. Turner, Lee G. Wilke, Alastair Thompson. A prospective, multi-center, randomized, double-arm trial to determine the impact of the Perimeter B-Series OCT System on positive margin rates in breast conservation surgery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT230.