Spectral signatures spot cancer

17 Jun 2002

Researchers in the UK have tested an optical biopsy technique during breast surgery on 200 volunteers.

Scientists at University College, London (UCL) have developed an optical method that could speed up cancer diagnoses.

The optical biopsy developed by David Pickard and colleagues is based on white-light scattering. Using a fiber-delivered xenon arc lamp source that emits from 320 nm into the near-infrared, the scattered light is collected by a second fiber and directed into a spectrometer. The scattered spectra have different "signatures" depending on whether the investigated tissue is cancerous or not.

The key to the technique lies in the interpretation of the scattered light spectrum. Pickard has developed algorithms that look for statistical correlations between the spectrum captured from suspect tissue and database spectra.

So far, the technique has been tested on 200 breast cancer patients, to examine breast tissue and lymph gland tissue (which is typically where breast cancers initially spread to). The optical biopsy result agreed with the conventional biopsy 93% of the time for breast tissue and in 85% of cases for lymph gland tissue.

Pickard told Optics.org: "We can set the specificity of the technique to a high level and pick up suspicious areas, or we can set the sensitivity to a high level, depending on how the system will be most useful clinically."

If used during surgery to remove tumors, the technique ought to help surgeons decide quickly whether to remove suspect lymph gland tissue. This normally takes a few days, while a tissue sample is analyzed by pathologists.

The scattering system was invented by Boston University researcher Irving Bigio, and has been patented by Los Alamos National Laboratory (LANL).

Pickard has now set up a spin-off company called medOptica to commercialize the research, and licensed access to the LANL technique is currently under negotiation.

The team has also worked on oesophageal and skin cancer. The first planned medOptica application is detection of Barrett's Oesophagus, a condition that is a precursor to oesophageal cancer.

The company has seed funding and is now seeking industrial partners to form a joint venture.

Author
Michael Hatcher is technology editor of Opto & Laser Europe magazine.