Micro-computed tomography (micro-CT) for intraoperative surgical margin assessment of breast cancer: A feasibility study in breast conserving surgery.

PURPOSE: Around 15%-30% of patients receiving breast-conserving surgery (BCS) for invasive breast carcinoma or ductal carcinoma in situ (DCIS) need a reoperation due to tumor-positive margins at final histopathology. Currently available intraoperative surgical margin assessment modalities all have specific limitations. Therefore, we aimed to assess the feasibility and accuracy of micro-computed tomography (micro-CT) as a novel method for intraoperative margin assessment in BCS.

METHODS: Lumpectomy specimens from 30 consecutive patients diagnosed with invasive breast cancer or DCIS were imaged using a micro-CT. Margin status was assessed on micro-CT images by two investigators who were blinded to the final histopathological margin status. The micro-CT margin status was compared with the histopathological margin status.

RESULTS: The margin status could be assessed by micro-CT in 29 out of 30 patients. Of these, nine patients had a positive tumor margin and 20 a negative tumor margin at final histopathology. Margin status evaluation by micro-CT took always less than 15 min. The margin status in 25 patients was correctly predicted by micro-CT. There were four false-negative predictions. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of micro-CT in margin status prediction were 86%, 56%, 100%, 100% and 83%, respectively. With micro-CT, the positive margin rate could potentially have been reduced from 31% to 14%.

CONCLUSIONS: Whole lumpectomy specimen micro-CT scanning is a promising technique for intraoperative margin assessment in BCS. Intraoperative quick feedback on the margin status could potentially lead to a reduction in the number of reoperations.