Quantification of the thermal signature of a melanoma lesion

Abstract

Melanomas are cancerous skin lesions that are notorious for their ability to metastasize at a relatively early stage of development. The key to improved survival in all affected individuals remains early diagnosis and treatment. We have recently developed a transient thermal (infrared – IR) imaging system that allows for accurate measurement of temperature differences on the skin surface to aid the detection and diagnosis of metabolically active or malignant skin lesions. The existence of a simple, quantitative, objective, and noninvasive in vivo screening and diagnostic tool for the evaluation of pigmented lesions would be invaluable for the early detection of melanoma in a variety of clinical settings. Therefore, we are currently conducting a patient study to verify the feasibility of the described IR imaging tool in distinguishing benign pigmented lesions from malignant ones and quantifying the malignant potential of lesions. In this paper, we compare data obtained by imaging benign and malignant pigmented lesions. Measured surface temperature distributions for characteristic time instants as well as temperatures of selected points on the surface of healthy skin are compared as a function of time. The results show a distinct difference in the thermal responses between healthy tissue and the malignant lesion for the cases considered in the paper. The thermal response of benign lesions was found to be similar to that of healthy skin tissue. This difference can be used to identify malignant lesions and quantify their malignant potential. Experimental data from the clinical study are compared with results obtained by simulating the thermal behavior of the skin lesion numerically using a computational model developed for this purpose. The computed results showed that the lesion parameters and properties can be estimated and the influence of malignant lesion on the transient thermal response can be quantified with our computational model.