Laser focus: detecting cancer through OCT10 April 2018
A team of European scientists has developed the world’s first cancer scanner that detects blood vessels grown by a malignant melanoma with an infrared laser beam. UK project leader Jon Holmes of Michelson Diagnostics tells Dave Callaghan how optical coherence tomography is enabling specialists to capture 3D images of microscopic structures under the skin in less than 30 seconds.
The battle to beat cancer has long been under way but, with advancements in technology, medical professionals are closer than ever to defeating this behemoth.
A European team has developed an infrared laser device that can detect blood vessels created by malignant melanomas – the most common cause of death from skin cancer – in under half a minute. It can be used to create a 3D colour image of the skin 1mm below the surface.
VivoSight technology is an enhanced version of optical coherence tomography (OCT), which is commonly used in retinal scans. It gives specialists the ability to quickly decide whether any detected cancer can be removed or treated with drugs.
Potential benefits of this new technique include removing the need for invasive biopsies and the weeks of anxiety that can occur while results are analysed. The harmless and quick scan will be able to detect melanomas by spotting the distorted blood vessels that are their calling card.
There are also significant cost savings to be made as the system gives instant results without the need for clinical procedures.
To beat a killer
Malignant melanomas, which are almost always caused by exposure to ultraviolet radiation from the sun, are difficult to treat, and the key is to catch them early. Survival rates are much higher if the treatment is started before the disease has spread to other parts of the body, especially the lymph nodes and major organs.
The UK project leader of the team behind this new technology, Jon Holmes of Michelson Diagnostics, which manufactures VivoSight, explains how it works. “OCT provides live subsurface images of skin to a depth of 1mm with unprecedented resolution that is approximately ten times higher than ultrasound,” he says.
“Now, with the technology developed, OCT has been further enhanced through dynamic OCT (D-OCT) that detects motion in the imaged skin, such as that caused by blood flowing through blood vessels and capillaries,” he says.
The ‘speckle’ or flicker of light patterns created by moving blood cells is picked up by the imaging device, which takes around four frames a second, and compiles the images so that a clinician may tell where something has moved.
“Using D-OCT, we can see the movement of blood against the solid tissue structures, which is something we have never been able to do before in a clinical setting,” continues Holmes. “It’s like looking out at night and seeing car headlights flowing along a motorway, only at depths of nanometres under the skin.”
Cancers don’t appear to take direct routes, however. “Their vessels are like twisting, branching country lanes that get narrower and wider,” he adds. “Our clinical team think that these ‘shapes’ are key to understanding the cancer. The scanner shows these vessels in gorgeous detail.”
The Automatic Detection of Vascular Networks for Cancer Evaluation (ADVANCE) project behind the innovation received a grant of €2.2 million from the European Commission’s FP7 research funding programme and has research teams based in five countries: Denmark, Germany, Italy, Serbia and the UK.
“It is the first available device that can image tiny blood capillaries in skin, and it does so non-invasively and instantly,” says Holmes. “Most skin diseases affect the blood vessels in the skin; being able to directly see these vessels and measure them gives the clinician new ways to diagnose disease and monitor treatments. In essence, it enables them to see under the skin surface instead of just looking at the top – just like X-rays can be used in dentistry to see tooth decay that is invisible to the eye at the surface.
“Every melanoma above a certain thickness could have spread to other parts of the body. At present, all patients with such melanomas have to wait for a sentinel lymph node biopsy that is performed in a hospital under general anaesthesia to find out if it is spreading. This can take weeks to perform, is very expensive and can be debilitating for the patient.
“About 80% of the time, the biopsy produces a negative result with no sign of the cancer spreading. There has to be a better way: our scanner may radically improve the abilities of dermatologists to decide whether a melanoma is in the less malignant, non-spreading, early stage, or if it has already developed and requires immediate aggressive therapy. Further clinical trials will be needed to conclusively prove the technology,” he says.
There are other ways in which the device can be used. “The scanner can image the blood vessels in healing wounds,” says Holmes. “This may have applications for the treatment of chronic leg and foot ulcers, when doctors want to know whether a wound is healing or requires a change in treatment, potentially reducing the number of amputations.
“ADVANCE technology may also help with burn victims, being able to give a doctor a quicker response time than the standard 15 days to determine whether a patient’s skin is healing and whether or not to give a skin graft.
“In the US, they are also working with our partner, Sciton, a Palo Alto-based laser manufacturer, on using D-OCT to optimise skin laser treatments for anti-ageing cosmetic procedures: reducing wrinkles; rejuvenating skin; removing scars and spider veins; and unwanted redness.”
The new technology is already being used in several different countries – particularly Germany – as a diagnostics tool. “D-OCT is being used by dermatologists to help them diagnose non-melanoma skin cancer, to monitor treatment to confirm the curing of cancer, and also to detect the borders of skin cancers that are to be surgically removed, saving the surgeon time and the hospital cost,” reveals Holmes.
The next steps for the team are determining further uses for the scanner, and developing its clinical and aesthetic applications. One area that was started by the ADVANCE research team was the assessment of malignant melanoma to determine how advanced a cancer is.
“There is much more to come from the processing of OCT data,” predicts Holmes, “and I foresee many further capabilities emerging from this, opening up many new clinical applications.”
This sort of technology has the potential to save thousands of lives, and many millions of euros every year. Freeing patients from unnecessary operations that may yield potential long-term, debilitating side effects, or waiting unnecessary amounts of time for treatment, will be priceless.
Another recent breakthrough in cancer detection came in the form of a blood test that can identify eight different cancers. The CancerSEEK test, which was trialled at Johns Hopkins University in the US, identifies tumour-related DNA mutations and proteins in the bloodstream, and has been earmarked as an important staging post towards a universal screening test for cancer.
With VivoSight offering a scan with immediate results and a new blood test providing an important development in detection techniques, we add effective tools to our arsenal for combatting this virulent disease and become one step closer to beating it for good.
Melanoma in numbers
- In the UK, 2,459 people died from the disease in 2014.
- In 2015, there were 15,906 new cases of melanoma skin cancer in the UK.
- Skin cancer was the fifth most common cancer in the UK in 2015.
- An estimated 9,730 people died in the US in 2017, with 87,110 new cases diagnosed.
- Approximately 91,270 new melanomas will be diagnosed in 2018 in the US.
- Early detection leads to a five-year survival rate of 98% in the US.
Source: Cancer Research UK and American Cancer Society