4 The diagnostic tests

4 The diagnostic tests

The interventions

VivaScope 1500 imaging system

4.1

The VivaScope 1500 imaging system is a non‑invasive reflectance confocal microscope system that uses a near‑infrared point‑laser light to get images of the top layers of the skin. These images are intended to be so highly magnified that they are quasi‑histological (comparable with microscopic examination of skin cells). The VivaScope 1500 system is console based and operates at a single wavelength of 830 nm.

4.2

The VivaScope 1500 imaging system includes software designed to analyse, store and display real‑time images of skin tissue in vivo, including skin cells, blood vessels, collagen and pigment. The images present a surface‑down view of the skin and may give information about the skin lesion's cell structure and the architecture of the surrounding tissues. This may help a clinician to make a clinical judgement and provide a positive or negative diagnosis of a cancerous skin lesion. Because the images do not give a transverse view of the skin, tumour thickness would typically need to be determined by histological examination of a biopsy.

4.3

The VivaScope 1500 imaging system is fixed to the skin by a magnetic ring attachment with a disposable adhesive window and a transparent, low‑refractive index medium between the skin and lens system. The system automatically scans the area of skin to which it is attached and is reported to give an image of the superficial reticular dermis (upper layer of the skin) to a depth of 250 micrometres at a resolution (ability to distinguish detail) of 1.25 micrometres. Overall, the set‑up time to attach the system and get an image is about 10 minutes, although this may vary depending on the experience of the user. The system is intended for diagnosing skin cancers and identifying lesions needing surgery, identifying the margins of lesions before and after surgery, and in monitoring the impact of non‑invasive treatments.

4.4

Another version of the VivaScope 1500 imaging system is the VivaScope 1500ML (Multilaser) system. This system is intended for use with fluorescent dyes for imaging skin in vivo or ex vivo, and is currently used in research settings.

VivaScope 3000 imaging system

4.5

The VivaScope 3000 imaging system is a handheld unit and is technically similar to the VivaScope 1500 imaging system. It operates with a single laser (830 nm) and images the superficial reticular dermis at a resolution of 1.25 micrometres. The handheld device is designed for imaging lesions in more difficult to reach areas, such as around the nose, eyes, ears, lips and gums. Unlike the VivaScope 1500 imaging system, the VivaScope 3000 imaging system is not attached to the skin surface but can be moved freely across the surface. The VivaScope 3000 imaging system is also intended for diagnosing skin cancers and identifying lesions needing surgery, identifying the margins of lesions before and after surgery, and in monitoring the impact of non‑invasive treatments.

The comparators

4.6

The comparators used in this assessment are current clinical practices used in the NHS to diagnose skin cancer and determine skin cancer tumour margins. These are:

  • examining skin using dermoscopy and clinical judgement to detect potentially cancerous lesions

  • examining skin using dermoscopy and clinical judgement to determine tumour margins.