Abstract B021: Use of wide field optical coherence tomography (WF-OCT) in margin assessment during breast conserving surgery (BCS) for ductal carcinoma in situ (DCIS)
Bibliographic record
Abstract
Abstract Purpose: To assess the utility of a novel imaging technology for intraoperative margin assessment in breast conserving surgery (BCS) for ductal carcinoma in situ (DCIS). Background: The multi-focal nature of DCIS presents a challenge to ensuring negative margins during BCS. Routine methods for intraoperative margin assessment, such as specimen radiography, ultrasound, cavity margins, and touch prep cytology each have specific limitations, including operator skill, time delay, probe position, and specimen completeness. A more recent method, wide field optical coherence tomography (WF-OCT), enables real-time tissue visualization at up to 2 mm of depth with the ability to use image-based machine learning to identify regions of interest suspicious for residual malignancy. Methods: Two adult females with biopsy-proven DCIS and one with invasive carcinoma underwent BCS following routine surveillance mammography and were prospectively evaluated. Primary lesions were imaged intraoperatively with specimen radiography and a WF-OCT imaging device (OTIS, Perimeter Medical AI, Toronto, Canada); images from both modalities were read to identify potential residual malignancy, and additional tissue was excised as indicated. Permanent histopathology was compared to imaging results. Results: The first patient (76 y/o, BI-RADS 4B, 1.6 cm) underwent BCS and the excised sample was 4 x 3.7 x 3.2 cm. By radiography, the biopsy clip and localization reflector were within the specimen and margins appeared satisfactory; WF-OCT demonstrated residual disease at the inferior margin and additional tissue was excised. Permanent histology showed DCIS involvement of inferior primary margin; additional margin excision contained DCIS and was negative. The second patient (64 y/o, BI-RADS 4B, 1 cm) underwent BCS and the excised sample was 4 x 3.5 x 3.5. By radiography, the biopsy clip and reflector were within the specimen and margins appeared satisfactory; WF-OCT showed residual disease at the inferior and posterior margins and additional tissue was excised. Permanent histology demonstrated DCIS within 1 mm and pleomorphic lobular carcinoma in situ (LCIS) microns from primary inferior margin; the additional inferior sample was margin negative, and posterior sample contained pleomorphic LCIS and was margin negative. The last patient (76 y/o, BI-RADS 5, 1.9 x 1.9 x 1.7 cm) underwent BCS and the excised sample was 6.5 x 5.3 x 4.2 cm. By radiography, the biopsy clip and localization reflector were within the specimen and margins appeared satisfactory; WF-OCT showed residual disease at the lateral margin and also revealed occult DCIS not found on biopsy. Additional tissue was taken until margin clearance by WF-OCT. Permanent histology demonstrated DCIS to <1 mm of primary lateral margin; the additional excision contained DCIS and was margin negative. Conclusions: In this case series of 3 adult females undergoing BCS for breast carcinoma, WF-OCT was a beneficial adjunctive imaging modality to specimen radiography for margin assessment. Citation Format: Amelia B. Tower, Andrew Berkeley. Use of wide field optical coherence tomography (WF-OCT) in margin assessment during breast conserving surgery (BCS) for ductal carcinoma in situ (DCIS) [abstract]. In: Proceedings of the AACR Special Conference on Rethinking DCIS: An Opportunity for Prevention?; 2022 Sep 8-11; Philadelphia, PA. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_1): Abstract nr B021.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".