An innovative imaging technique which measures skin stiffness could help doctors monitor skin lesions, providing added information for diagnosing skin cancer cheaply and easily.
Scientists from The Institute of Cancer Research, London, have developed a new elastography technique that can analyse skin lesions by looking at how tissues move when they are stretched.
Their new method records changes in the pattern of lines on the skin to measure skin stiffness, which could help decide which skin lesions are cancerous.
The researchers, whose study is published in the Journal of Biomedical Optics, said the technique could be cheaper than other elastography techniques and could, with more development, help patients avoid unnecessary skin tumour biopsies, and receive better surgery when excision does turn out to be necessary.
Our skin changes with age, becoming less “springy” as we get older, but other factors like illness and disease affect our skin too. Elastography measures changes in stiffness of body tissues in order to help doctors diagnose diseases like cancer.
Most areas of human skin are covered in a pattern of lines which is disrupted when skin cancer begins to form. Other optical surface elastography techniques under development use expensive laser based systems or need a pattern of markers painted on the skin to help record how skin moves when stretched, but this is undesirable if there is a break in the skin, which may increase the risk of infection; the markers may also be difficult to see on heavily pigmented skin or lesions.
Scientists at The Institute of Cancer Rese arch (ICR) investigated if directly measuring the motion of skin line patterns could be used as a way of determining skin stiffness. They used 16 silicon replicas, representing skin from various age groups and parts of the body, to see if “skin line pattern elastography” could measure skin stiffness for different skin types. The skin replicas were stretched under lab conditions and camera equipment was used to record images before and after stretching.
The researchers found that their imaging equipment was able to track how each replica’s skin line patterns changed when stretched. From this changing skin line pattern, they were able to calculate the average strain.
They produced a skin replica with a thicker region to test if their new technique could distinguish between areas of skin with changing levels of stiffness, which would act differently when stretched. They found that the strain they measured from the skin line pattern for each region was consistent with its degree of stiffness.
They also tested their new technique on a patient with a suspected malignant melanoma and found that it could measure the changes to the skin line pattern even within the pigmented area.
Dr Jeffrey Bamber, Team Leader in Ultrasound and Optical Imaging at The Institute of Cancer Research, said: “The skin is a complex organ that can tell us a great deal about our health. This study is interesting because no one has thought to evaluate skin tumours in exactly this way before. As we learn more about cancer we are realising that the events which lead to the spread of cancer are a result of cells sensing and manipulating the mechanical properties of their environment, as well as their chemical properties.
“In skin tumours, structural variations occur on and below the skin, and they are also associated with disruption to the skin line pattern. These features can be different for malignant melanomas and (harmless) moles. More research is needed before this work could be translated to the clinic, but this proof-of-concept study shows that it’s possible to use simple low cost optical imaging equipment like video cameras to record relative skin stiffness, which could be a cheap and easy way of helping doctors to diagnose cancer.”