When a patient is diagnosed with prostate cancer, doctors often decide to remove the gland and some of the surrounding tissue, but the procedure isn't always perfect, and in some cases either too little or too much tissue is removed. A new technique might significantly improve the accuracy of the procedure, using a reflected light technology to detect left-behind cancer cells during the surgery.

The research, which is lead by a team at the University of Texas Southerwestern Medical Center, makes use of a novel light reflectance spectroscopy probe. Essentially, the intensity of light reflected or scattered back from tissues during surgery is analyzed, with scientists able to look at the data to pinpoint cancer cells that weren't removed with the prostate gland.

These usually undetectable cancer cells reside outside the visible tumor, in an area referred to as a "positive surgical margin." Surgeons often remove some of the tissue surrounding the prostate gland in order to catch any nearby cancer cells, but sometimes it might not actually have been necessary to do so – if that tissue was, in fact, cancer free – or some cancer cells might be left behind despite the removal of extra tissue.

Using the probe, the researchers attempted to determine its effectiveness at detecting dangerous cells in the margin. They worked with 17 patients with medium-to-high risk diseases that required immediate prostatectomy.

As soon as the glands were removed, the researchers used the probe on surgical margins where it was suspected that cancer cells might still be lurking, with samples of said tissue then being removed for analysis in the lab. After testing the samples for cancer cells, the researchers found that the light reflectance spectroscopy technique had successfully identified positive surgical margins – those where dangerous cells were still present – with an accuracy of 85 percent.

"This study highlights one of a growing number of technology platforms that aim to improve the outcomes of cancer surgery," said UT Southwestern's Dr Jeffrey Cadeddu. "Further study is required to determine whether such analysis may be used in real time to improve surgical decision-making and decrease the amount of tissue surgeons need to remove."

The findings of the work were published online in the Journal of Urology.