Page 34 - Noninvasive Diagnostic Techniques for the Detection of Skin Cancers

planning. Ultrasound biomicroscopy (UBM), a technique generally used in the diagnosis of
various eye abnormalities, has demonstrated preliminary usefulness in differentiating the
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histological components of cutaneous BCC and SCC, 98,99 and eyelid lesions. For patients with
BCC, High Frequency Ultrasound has also been explored to evaluate tumor margins. 101

Theoretical Advantages
Ultrasound is advantageous in the evaluation of skin lesions because it is noninvasive,
reproducible, safe, and cost effective. 39,89,102,103 Depth and thickness of a variety of tumors can be
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evaluated including, benign nevi, BCC, SCC, and melanoma. A 2010 retrospective study
comparing ultrasound diagnoses with clinical diagnoses versus clinical diagnoses alone, in
relation to histologic determination, demonstrated that ultrasound increased accuracy of clinical
diagnosis. While referring diagnosis was correct in 73 percent of 4,338 lesions, the addition of
the ultrasound evaluation improved diagnostic accuracy to 97 percent (P<0.001 for the
difference). 104 The study concluded that noninvasive ultrasound imaging of skin lesions provides
important clinical information, which improves accuracy of diagnosis and has value in pre-
operative therapy. A 2007 retrospective study examined the usefulness of high frequency
ultrasound in the diagnosis of BCC through the identification of hypersonographic spots. 105 This
study concluded that multiple (more than five spots per lesion) hypersonographic spots versus
other identified patterns of hypersonic spots may assist in differentiating between BCC and
melanoma.

Theoretical Disadvantages
A limitation of the technique, identified in Wortsman 2010, 104 was its lack of sensitivity in
detecting lesions localized to the epidermis or extremely thin lesions.

Variations of Technique
• Reflex Transmission Imaging (RTI). This is a particular form of high resolution
ultrasound that can be joined with white light digital photography for classification of
pigmented lesions. The RTI device, termed DermaScanC, reveals the vascularization of
tumors seen with color Doppler sonography (B-mode). This technique may reduce the
number of referrals for benign tumors without missing melanoma; however, the small
number of studies assessing its use and expense may limit its utility.
• Color-coded duplex sonography. This technique involves coupling a B-mode (brightness)
image with a pulsed wave Doppler, and provides data on blood flow in real time. One
study identified the usefulness of this technique in its ability to distinguish between
melanoma and other pigmented skin lesions; 106 two other studies demonstrated its
potential as a prognostic tool for the identification of melanoma with high metastatic
potential. 107,108
• Laser Doppler perfusion imaging. This technique is able to discriminate differences in
perfusion levels between malignant melanoma and benign pigmented skin lesions.
Vascularization of melanoma lesions has been a primary interest for researchers because
of the hypothesized theory that vascularization gradually increases during the transition
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of a lesion from benign to dysplastic to primary melanoma. Early studies regarding the
use of this technique to differentiate between benign and malignant melanocytic skin
tumors reported its usefulness as a discriminative adjunct in assessment; there were no

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