Near‐infrared heating of skin to delineate non‐melanoma skin cancer lesions: A pilot study

Abstract

Background Surgical excision is a mainstay of treatment for non‐melanoma skin cancer (NMSC); improving margin delineation can reduce the need for further monitoring/treatment. The objective of this pilot study was to determine if near‐infrared radiation (NIR) application to skin causes visible changes in normal and NMSC skin, to help delineate margins. Materials/Methods Eleven biopsy‐proven NMSC lesions were included. The skin was then heated under a 175W NIR heating bulb; margins were traced onto acetate film before and after heating. Lesions were then randomly assigned to excision based on pre‐ or post‐heating margins. Composite images were generated by overlaying the heat and no‐heat lesion contours. All specimens were sent for histopathology. Results The range of closest margins in the control group was 2.0‐3.0 mm with a median of 2.0 mm; the range in the intervention group was 4.0‐9.0 mm with a median of 5.0 mm. Composite images showed larger heat contours when the initial lesion was larger. There was a statistically significant difference between the two groups. Overall, NIR light caused visible hyperaemia to skin, and more intense erythema to malignant skin lesions. Conclusion Near‐infrared light may have use in an outpatient setting for skin cancer delineation, possibly reducing the rate of positive margins.