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How To: Enhanced Intraoperative Communication of Tumor Margins Using 3D Scanning and Mapping

by Kayvon F. Sharif, BA, Kavita Prasad, BA, Alexis Miller, BS, Shira McPeak, PA, J. Elliott Denney, MD, James S. Lewis Jr., MD, and Michael C. Topf, MD •

RESULTS

Intraoperative margin status was communicated with the aid of CAD specimen mapping in 12 cases. Median 3D image acquisition time was 7:18 (range 6:54–8:31). Operations consisted of six (50%) oral cavity composite resections, including two segmental mandibulectomies, two marginal mandibulectomies, and two without bony resection. Other operations included two (17%) transoral robotic surgeries (TORS), two (17%) partial glossectomies, one (8%) total laryngectomy, and one (8%) wide local cutaneous excision. Pathology was squamous cell carcinoma in all but one patient, who had a minor salivary gland (mammary analogue) secretory carcinoma of the buccal mucosa. Intraoperative margins were assessed by frozen section using a specimen-based approach in all cases.

Intraoperative specimen margin status was negative in four (33%) cases, and no further resection was required. The remaining eight cases involved close (<5 mm) (n = 3, 25%), focally positive (n = 3, 25%), or severely dysplastic (n = 2, 17%) margins initially seen on frozen section. 3D specimen maps successfully illustrated the anatomic site of each involved margin sampled from the en bloc resection specimen, thus providing visuospatial guidance for margin re-localization. Immediate re-resection was performed in five (42%) cases. Each case of re-resection resulted in a negative final margin status, although not all re-resection specimens contained malignancy.

In the two TORS cases, there were 1 mm and focally positive intraoperative margins. In case #9, the tumor was found to be extending through the superior constrictor on the main specimen with exposed external carotid artery in the defect; therefore further re-resection was not performed, resulting in an R1 final margin status. In the other TORS case, the superior constrictor was already resected in its entirety and freely mobile on the deep aspect of the main specimen, precluding further resection of the close (1 mm) margin. In case #8, frozen section showed an adequate 5-mm margin, which was found to be close (1 mm) on final pathology.