Dual-Wavelength Subtraction Optical Imaging for Delineating Cutaneous Tumors

Abstract

Nonmelanoma skin cancer (NMSC) is the most common form of malignancy worldwide. Currently, dermatologic surgeons visually assess tumor boundaries prior to excising the cancer. This approach is challenging because of limited intrinsic contrast between malignant and normal skin. The objective of this work was to evaluate dual-wavelength subtraction optical polarization imaging (OPI) for pre-operative delineation of NMSC margins. Forty-nine patients scheduled for Mohs micrographic surgery were enrolled in this study approved by the Institutional Review Board of the Massachusetts General Hospital. Before lesion resection, clinical borders of the excision were outlined by the study surgeon using a purple marker. Wide-field cross-polarized optical reflectance images were acquired at 440 nm to display the dermal collagen structure, and at 640 nm to show the surgeon’s marker. Routine Mohs surgery then proceeded. Optical images were encoded using spectrally-dependent properties of skin chromophores to reduce the impact of background pigmentation and vascularization. Pre-operative tumor margin evaluations from OPI were compared to visual assessments by the surgeon and to standard of care histopathology. In total, fifty-three lesions were evaluated, including forty-two basal cell carcinoma (BCC) (79%) and eleven squamous cell carcinoma (SCC) (21%). In all thirteen cases (25%) requiring more than one Mohs stage, OPI accurately visualized the entire tumor-involved region. Overall, tumor boundary assessments from OPI correlated very well with histopathological findings (sensitivity: 100%, specificity: 98%). This optical imaging method may provide a rapid and reliable tool to optimize surgical treatment of dermatologic cancers.

Speaker

Peter R. Jermain
UMASS Lowell Advanced Biophotonics Laboratory
United States

Discussion

Ask question