Room: Exhibit Hall | Forum 6
Purpose: To explore the feasibility and potential of micro-CT to be used as a surgical guidance tool for breast conserving surgery (BCS) in delineating the surgical margin status. Over 20% of patients undergoing breast conserving surgery require a second re-excision surgery due to an incomplete initial tumor resection.
Methods: A cohort of 30 lumpectomy specimens were scanned with a pre-clinical micro-CT system in the surgical gross lab of the pathology department, within minutes upon specimen arrival. Specimens were compressed with an acrylic holder, fabricated in-house, scanned with the micro-CT (72 sec scan time, 90 sec reconstruction time), optically imaged to capture the orientation ink markings, and then immediately returned to the pathologist assistant for standard histological processing. After specimen imaging, a specialized breast imaging radiologist read the scans in two orthogonal planes and marked locations where a positive margin, defined at invasive or in-situ cancer â€œon-inkâ€?, were found. These results were then compared against the final histological report, where the minimum distances to invasive and in-situ cancer are listed for each margin.
Results: The micro-CT was able to accurately reconstruct each specimen; however, metal artifacts were significant in specimens that underwent wire and/or clip tumor localization. To date, 13 specimens have been analyzed by the radiologist and undergone final assessment by pathology. Of this set, there was 1 true positive, 10 true negatives, 1 false positive, and 1 false negative. This study is ongoing with the remaining specimens still to be analyzed and additional specimens continuing to be imaged.
Conclusion: This work demonstrates the feasibility of micro-CT to be used as a surgical navigation tool in the BCS clinical workflow. Case examples highlight instances where micro-CT could accurately locate the tumor margin in 3D, but state-of-the art 2D specimen mammography would incorrectly determine the closest margin.
Funding Support, Disclosures, and Conflict of Interest: This work was funded by the National Institutes of Health grant R01CA192803.
Microfocus X-ray, Breast, Cone-beam CT