Page 10 - Noninvasive Diagnostic Techniques for the Detection of Skin Cancers

magnifying lens equipped with a polarized or nonpolarized light source (to deflect surface
reflection) that is held near the suspicious lesion. Other diagnostic techniques include confocal
microscopy, which produces images of skin lesions at various depths and is primarily used in
research centers. Some of these devices have been approved or cleared by the FDA; others are in
general use (e.g., photography). In addition, a number of imaging modalities are emerging to
help improve the diagnostic accuracy of visual inspection of pigmented skin lesions. These
include epidermal genetic tape stripping, ‘scent’/‘odor’ ultraviolet photography, fluorescence,
ultrasound, laser Doppler, bio-electrical impedance, polarized light photography, 3-D histograms
of color mapping, multispectral imaging and fully automated computer-based analysis, and
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thermography. To evaluate these newer techniques, several comparators have been used. In
addition to the direct comparison with the “gold standard,” the biopsy, several studies have
highlight comparisons between the newer devices and the clinical exam, as well as head-to-head
comparisons between these devices.

Statement of Work/Objectives
The objectives of this technical brief are to provide a description of the state of the science of
noninvasive imaging modalities in diagnosing cancerous tumors of the skin, proffer an analytic
framework for assessing the applications of the devices, provide a summary of ongoing research,
and to delineate future research needs.
Three principal forms of skin cancer will be considered: basal cell carcinoma (BCC) and
squamous cell carcinoma (SCC), the more prevalent forms of skin cancer, and melanoma, among
the most virulent. While the focus of this brief will be on modalities currently in general or
limited clinical use and/or FDA approved or cleared, we also will consider investigational
technologies based on available data and input from our key informants particularly the potential
importance of these technologies and where they might fit into the care process.
For the purpose of the present discussion, we considered these modalities according to the
degree of resolution of the skin lesions, ranging from clinical inspection (quaternary and tertiary)
to delineation of cellular and subcellular structures (secondary and primary), adapted from
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Marghoob 2003. We also examine whether there are indications of differing effectiveness
among techniques for the early detection of skin cancers among Whites, Blacks, and Hispanics,
and whether that should be a focus of future comparative effectiveness research. Whenever
possible, we stratify the findings by whether or not the patients had a previous history of skin
cancer and whether or not patients have a history of other malignancies. The rationale for this is
the growing recognition of skin cancer as a leading form of second malignancy. 1,11 We also
sought to assess the clinical application of these modalities and their diffusion across
specialty/subspecialty groups.

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