Shedding light on breast cancer

09 Apr 2009

Optical interrogation could help oncologists individualize treatments for breast cancer.

Probing breast cancer

Researchers at Duke University in North Carolina, US, hope to commercialize a needle-based fibre-optic tool that provides important clues about the aggressiveness of a tumour in situ. The team claims that its technique could help with disease prognosis as well as planning the best course of therapy for each patient (Cancer Research 69 OF1).

"While our technique is not an anatomical imaging modality like magnetic resonance imaging or X-ray, it can provide valuable quantitative physiological information that these methods cannot," Quincy Brown, an associate professor at Duke's Pratt School of Engineering, told optics.org. "Our method would be complementary to these imaging techniques and can provide information about the microenvironment of a tumour."

The Duke technique uses diffuse reflectance spectroscopy to determine oxygen levels within a tumour. Past studies have shown that low levels of oxygen (a condition known as hypoxia) is more often associated with malignant tissue than healthy tissue. What's more, tumours that thrive in these low-oxygen environments tend to be more difficult to treat.

By using a spectroscopic approach, oncologists can obtain immediate and nondestructive feedback on the biological specifics of the tumour, enabling them to choose the most effective treatment for the patient.

"Our optical spectroscopy method is feasible for use in the breast in vivo," commented Brown. "At the same time, this approach provides an easier-to-use and robust alternative to more commonly used pathology methods that require removal of tissue and days of tricky processing,"

In the set-up, an optical spectrometer, which consists of a 450 W xenon arc lamp and CCD detector, is coupled to a fibre-optic probe. The probe is guided through a needle to the region of interest to deliver and collect light from the tissue.

"The absorption spectrum of blood changes as a function of how much oxygen it is carrying, which provides a convenient way to measure the amount of oxygen available to or used by the tissue," explained Brown. "Currently, our technique probes to a depth of about 1–2 mm from the tip of the fibre optic, but this can be expanded into the near-infrared if deeper sensing is required."

Brown and his colleagues are carrying out a pilot study to perform spectroscopic measurements prior to and following chemotherapy. "We hope to expand the study and collect more data on the value of optical spectroscopy in planning or monitoring cancer treatment," concluded Brown.