Imagine if it was possible for a surgeon, when operating on a patient with breast cancer, to insert a microscope into the tissue and watch cancer cells as they are formed. Well, a group based at Imperial College London, led by Dr Khushi Vyas, has developed such a device – which is called a line-scan confocal laser endo-microscope – that is less than 1 millimetre in diameter (seen right, © Khushi Vyas). About the width of 25 human hairs, the instrument has been designed to be inserted using a Mammobot to provide real-time images at cellular resolution.
Vyas and her colleagues have recently published a paper in which they described their findings. In this preliminary study, tissue samples from 15 patients who underwent breast cancer surgery were studied: 5 with normal glandular tissue, 5 with benign fibroadenomas, and 5 who had ductal carcinoma in situ (DCIS) with concurrent invasive ductal carcinoma. For each tissue sample, videos were acquired at 120 frames/second from different scanned sites on the tissue surface. In addition, standard histopathological analysis of the excised tissue was also performed following oncological resection.
Representative results (seen left, © Khushi Vyas) enable comparison of the endo-microscope images (top row) – [A] normal lobule; [B] fibroadenoma; and [C] invasive ductal carcinoma – with their corresponding H&E stained histopathology images [D], [E] and [F] in the bottom row. The authors showed that their system allows for non-invasive and real-time “virtual” histology imaging of freshly excised breast tissue specimens without having to section and fix them. They said their endo-microscope can identify discernible features in normal ducts and can also distinguish DCIS from invasive ductal carcinoma at sub-cellular scale.
Vyas and her colleagues concluded: “Such a miniaturized tool could be very useful as the next generation mammary ductoscope for full duct outline mapping by detecting cancer or pre-cancerous lesions in the milk ducts in real-time, thus minimising the risk of re-operation, morbidity and costs associated with surgical interventions.”
The next step for the team will be to test their instrument in a clinical setting with patients, acquiring their digital histological images in vivo, rather than in ex vivo tissue samples (as seen above left). Their hope is to help reduce the need for follow-up operations by removing cancerous cells that might previously have evaded detection. Unlike many inventors who are prone to hyperbole, Viyas (seen right) is circumspect, commenting: “Our aim is to proceed to clinical trials with a view to the system becoming available for deployment in around five years.”