Optical method speeds cancer diagnosis in surgery

01 Oct 2013

Offers potential to revolutionize the surgical treatment of cancers.

Tissue-conserving cancer surgery is a highly skilled procedure which involves time-consuming tissue preparation to detect the margins of cancerous tissue. The goal is to remove as much of the tumour as possible while sparing healthy tissue.

With funding from the National Institute for Health Research(NIHR), experts at the UK’s University of Nottingham has developed a highly accurate prototype technique to produce a detailed "spectroscopic fingerprint" of each tissue layer removed during surgery.

This technique, which can produce detailed maps of the tissue rich in information at the molecular level, has the potential to speed up and improve the diagnosis of cancer tissue during the operation as well as reduce unnecessary surgery.

The research has been published in the journal Proceedings of the National Academy of Sciences and the team, led by Dr Ioan Notingher in the School of Physics & Astronomy, are now looking to build an optimised instrument that can be tested in the clinic.

Dr Notingher said, "By refining our prototype instrument, diagnosis of each tissue layer could be obtained in a few minutes rather than hours. Such developments have the potential to revolutionize the surgical treatment of cancers. This technology will provide a fast and objective way for surgeons to make sure that all the cancer cells have been removed whilst at the same time preserving as much healthy tissue as possible."

Tissue-conserving challenges

Typically, skin-conserving surgery involves cutting away layers of tissue, one after another, to ensure all traces of cancer are removed. This lengthy process is halted when only health tissue is left.

Successful removal of all cancer cells is the key to achieving lower rates of the cancer returning but there is always a balance to be struck between making sure all the cancer is removed and preserving as much healthy tissue as possible in order to reduce scarring and disfigurement.

Notigher added, "The real challenge is to know where the cancer starts and ends when looking at it during an operation so that the surgeon knows when to stop cutting. Our technique can also diagnose the presence or absence of skin cancer in thick chunks of skin tissue, making it unnecessary to cut the tissue up further into thin slices. "The use of lasers and high-sensitivity light detection technologies allows faster and more sensitive imaging of tissues and discrimination of tumours."

One particular technique, known as Mohs surgery — microscopically controlled surgery — is used for the treatment of difficult cases of a type of skin cancer called basal cell carcinoma (BCC), the commonest cancer in humans with more than 60,000 new patients diagnosed each year in the UK alone.

Mohs surgery provides the highest cure rates for BCC, but the procedure takes a lot of time because each new tissue layer has to be frozen and examined during the operation, which can take as long as seven hours in total. From a patient’s perspective, there is a need to reduce the Mohs surgery time by developing faster and objective ways of seeing whether the cancer has been completely removed during a shorter operation under a single local anaesthetic.

Notingher’s technique uses an integrated optical technique based on auto-fluorescence (natural fluorescence from the tissue) and Raman spectroscopy (a highly sensitive technique using lasers to identify the molecules in a tissue sample). "Our technique does not rely on time consuming and laborious steps of tissue fixation, staining, labelling or sectioning. The beauty is that it can be automated and very objective."

About the Author

Matthew Peach is a contributing editor to optics.org.