Trial Outcomes & Findings for Wide Field OCT + AI for Positive Margin Rates in Breast Conservation Surgery. (NCT NCT05113927)

Of the 661 participants who consented, 46 were screen failures, resulting in 615 started (613 enrolled) participants. The study included a 133-participant training phase and a randomized phase split into Part A (n=165) and Part B (n=317). In Part B, 317 participants were randomized 2:1 to either the Device Arm with ImgAssist 2.0 (n=208) or the Control Arm (n=109). Two participants were withdrawn prior to surgery from the device arm, leaving 613 for safety analysis and 206 for endpoint analysis.

Wide Field OCT + AI for Positive Margin Rates in Breast Conservation Surgery.

This endpoint is a within-subject comparison of the occurrence of at least one unaddressed positive margin following standard of care (SOC) alone versus after the adjunctive use of the device (SOC + Device). An "unaddressed margin" is an actionable margin where the surgeon could have excised additional tissue but which is determined to be positive by pathology. Positive margin criteria follow NCCN and SSO/ASTRO guidelines: "ink on tumor" for invasive carcinoma and \< 2 mm for DCIS.

This measure is a within-subject comparison of the mean number of unaddressed positive margins determined through histopathology following SOC treatment alone versus SOC + Device use. An "unaddressed margin" is defined as a final margin where further tissue could have been excised but which was determined to be positive by pathology.

A within-subject comparison of the number of "false-positive" shaves, defined as any shave where pathology reported no presence of cancer (cancer-free), taken during SOC alone vs. the supplemental use of the Device.

According to the joint consensus guidelines by the Society of Surgical Oncology (SSO) and the American Society for Radiation Oncology (ASTRO), a positive margin for invasive carcinoma is defined as "ink on tumor" (1). For ductal carcinoma in situ (DCIS), including DCIS with microinvasion (DCISM), the NCCN defines a positive margin as \<2 mm and DCIS with microinvasion is further characterized as an invasive focus ≤1 mm in size) (2). For cases involving invasive carcinoma with a DCIS component, the SSO/ASTRO Guidelines apply the same definition of a positive margin-"ink on tumor"-to both invasive carcinoma and DCIS. Similarly, for participants who have undergone neo-adjuvant therapy, the "ink on tumor" definition is used for both invasive carcinoma and DCIS

A post-hoc analysis was conducted to assess accuracy as an additional measure of margin-level effectiveness for clinical decisions aided by the B-Series, with the following definition in the Full Analysis Set based on terms as defined in SAP Table 1b, where T=true, F=false, M=missing, P=positive, and N=negative. Clinical decision accuracy = (TP+TN)/(TP+TN+FN+FP+MP+MN). This analysis does not reflect true (per margin) sensitivity or specificity of device standalone performance but instead measures clinical decisions aided with the Device after SOC was completed.

Subject-Level Effectiveness of Clinical Decisions aided with Device on Final SOC Margins with "Ground Truth" Pathology results Based on NCCN and SSO/ASTRO Guidelines

This analysis does not reflect true (per subject) sensitivity or specificity of device standalone performance but instead measures clinical decisions aided with the Device after SOC was completed.

Assessed by recording all adverse events for the duration of the study and then analyzing by seriousness, severity, and device/SELENE procedure-relatedness.

The BREAST-Q BCT (v2.0) assessed breast satisfaction using a 0-100 scale. The questionnaire includes pre- and post-operative scales, each using a range from 0 (very dissatisfied) to 100 (very satisfied) Pre-operative surveys were given after consent, while post-operative surveys were completed 4-12 weeks after surgery. This window ensured data was collected before radiation therapy to avoid confounding cosmetic results. To measure changes, three identical questions scored 1-4 were analyzed, with positive values indicating improved satisfaction. Descriptive statistics were reported by treatment arm and for a subgroup without oncoplastic closures. For missing data, if at least 50% of items were answered, the mean score was imputed for the total; otherwise, the scale was not scored. This methodology ensured satisfaction was captured before adjuvant treatments impacted outcomes.