To assess the use of a handheld optical coherence tomography (OCT) probe for the evaluation of intraoperative surgical margins during partial nephrectomy (PN).

In an initial feasibility study, a radical nephrectomy specimen with a 9-cm tumor was cut into 19 sections, exposing 0 mm (n = 8), 1 mm (n = 6), and 2 mm (n = 5) gross margins. OCT was used to determine the margin width in each specimen. Second, a prospective ex vivo assessment of 15 PN tumor specimens was performed with OCT to determine margin status and to measure the attenuation coefficient of tumor and renal parenchyma.

Median OCT margin width measurements for sectioned samples were 0 mm, 0.9 mm (range 0.7-2.9 mm), and 2.7 (range 1.65-2.8 mm) for grossly 0 mm (positive), 1 mm, and 2 mm margins, respectively. The difference between measurements from all margin groups was statistically significant (P <.04). The sensitivity and specificity for identifying positive margins were both 100%. In the PN specimens, OCT correctly found that all specimens had negative margins (within <.0001).

We have demonstrated the feasibility of using a handheld OCT probe to assess margins ex vivo during PN. OCT may reduce the need for intraoperative frozen section and aid in minimizing parenchymal excision.