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Non-invasive technology looks beneath the skin
SKIN specialists and doctors began to benefit a few years ago from a new technology developed in the UK, initially to aid early detection of skin cancer – the first non-invasive system to be able to “look” beneath the surface of the skin.
Since then this remarkable invention has proved its versatility in a growing variety of skin health and other medical applications. Before the advent of the SIAscope, to find what lay beneath the outer layer of skin it had been necessary to carry out a biopsy and send it away for analysis — a time-consuming process that does not favour the patient when early detection can make an enormous difference to their chances of survival.
The SIAscope, based on technology originated at the University of Birmingham in the English Midlands, involves employing an innovative form of image analysis to examine skin lesions and enable particular disorders to be identified.
By using it, doctors can rapidly tell the difference between skin cancer and other types of skin damage. This allows the cancer to be identified earlier and treated more quickly, and hence with greater success. Furthermore, the system’s usefulness has recently been assessed in a growing number of other situations.
Based on a scanning technique using harmless light, in a sequence of visible (red, green and blue) and infrared wavelengths from 400 to 1,000 nanometres, the instrument represents the culmination of a very successful collaboration between physicists, computer scientists and the medical profession, along with the high-tech company Astron Clinica that has commercialised the invention.
Light interacts with tissue in different ways depending on the composition of the tissue. The SIAscope measures the amounts of the different frequencies of light that are absorbed, scattered and reflected by skin.
Computer software uses a mathematical model to compare the reflectance properties with the results expected from normal skin tissue. Subsequently, it constructs images that show the tissue composition at more than 350,000 points in the skin within a scan area of 11-millimetre diameter to a depth of about 1,000 nanometres (one micro-metre), enabling a doctor to detect early signs of cancer or recognise other skin complaints.
The system completes a scan in under five seconds and processes the data to create a series of images in about 10 seconds. These SIAgraphs as they are known (which can also include 3D representations) image the concentrations of melanin, dermal melanin, blood and collagen in the scanned area.
Storage of all images within the machine aids patient management by allowing scans to be compared with earlier results, revealing for instance, any change in dermal melanin. The user may also download scans and send them back to Astron Clinica by e-mail or on CD for an expert second opinion.
The manufacturer can also remotely “interrogate” any machine via the Internet for maintenance, servicing and software support.
The system is now being used routinely in a number of UK hospitals and clinics, including Solihull Hospital (central England), following the original clinical work in the plastic surgery department of New Addenbrooke’s at Cambridge.
Trials are even under way in which the skin scanning and image storing process is undertaken by a primary care nurse, with later diagnosis by the family doctor (GP), and experience from these has shown that, in fact, a nurse can acquire the melanoma diagnosis data using the SIAscope.
Skin cancer is a growing scourge around the world and overseas purchasers include a number of specialists and primary care clinics in Australia where it is a particularly serious problem. In the United States a system has recently been sold to the University of California Irvine (UCI) for work in dermatology/pigmented lesions clinics. The SIAscope has full FDA approval and the manufacturer has appointed a distributor in California for the US, where the target markets include private dermatologists and specialised plastic surgeons.
In Europe the system has been aimed at both dermatogists and social medicine (National Health Service) clinicians. In Australia it is finding markets down to GP level, specially in remote communities. The easy portability of the new version makes it particularly suitable for use in the outback where there is a relatively high incidence of skin cancer.
Cambridge-based manufacturer Astron Clinica has patented the technology and is continually refining and extending its applications. An improved version which is now of portable briefcase size and provides enhanced image quality is expected to attract many more users at a time when melanomas are a growing concern. At the same time it has also become apparent that the clinical applications in which the SIAscope can aid both the dermatologist and the primary care medical practitioner are much wider than originally thought: it is already being trialled in psoriasis and eczema at St Thomas’s Hospital in London.
A version of the SIAscope is even being studied to help fight serious eye diseases such as those often associated with diabetes. Funded by a grant from the Engineering and Physical Sciences Research Council this research aims to extend the scanning technique to the early diagnosis of diseases of the retina that can cause blindness if not treated promptly.
“The SIAscope is now becoming established in clinical use for melanoma diagnosis,” said Dermot Walsh, sales director of Astron Clinica, “but we are building on this success with extensive research programmes for applications in other skin cancers and a wide variety of other disorders. What looked at one time like a simple mole-checking device has blossomed into a versatile imaging device with an enormous range of potential applications.”
The ability to use the system for a greater variety of purposes greatly enhances its cost-effectiveness. One such application being assessed at present is to image the invasive cells of a basal cell carcinoma. This gives the surgeon a view of the full extent of the carcinoma, thus ensuring that all the affected tissue will be removed.
In another potential application, medical researchers can use the SIAscope to measure changes in the blood supply to the skin. This will enable them to monitor the progress of wound healing, for instance, and to work in collaboration with pharmaceutical companies to check the effectiveness of relevant products during development.
But the technology still needs to be proved for routine use in these applications and production software finalized. — Dawn/London Press Service
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