Multimodal imaging for nonmelanoma skin cancer margin delineation.

Abstract

Nonmelanoma skin cancer (NMSC) is the most common form of cancer worldwide. The most effective form of treating this cancer is its surgical removal. As NMSC rarely metastasize, its complete excision is often curative. We investigated the potential of combining Terahertz Pulsed Imaging (TPI) with polarization enhanced reflectance optical imaging for the accurate intraoperative delineation of NMSC. Fresh thick samples with residual cancer were obtained from surgeries. The samples were imaged within two hours using polarization optical and TPI systems without remounting. Analysis of the TPI results was performed in the frequency domain. Co- and cross-polarized optical images were acquired at 410 nm. Superficial optical images were obtained by subtracting cross-polarized from the respective co-polarized images. Terahertz, optical, and histological images were overlaid and compared. Our results show that the frequency powers of diseased and normal skin tissues differ significantly at 0.47 THz. While TPI has demonstrated contrast between diseased and normal tissue, it can also highlight normal structures. As TPI alone lacks the resolution necessary to distinguish between tissue types morphologically, polarization optical imaging was used for the inspection of the suspicious areas highlighted by TPI. Combined TPI and optical imaging has the potential for quick intraoperative delineation of cancers. Lasers Surg. Med. 49:319-326, 2017. © 2016 Wiley Periodicals, Inc.