Fluorescent brain cells may guide surgeons

HEIDELBERG, Germany, April 7 (UPI) -- German scientists say they've developed a technique designed to improve neurosurgery involving gliomas -- malignant brain tumors.

Brain tumors are often resistant to chemotherapy, growing fine extensions that infiltrate normal brain tissue and often forming satellites in surrounding tissue, researchers said. That makes it nearly impossible to remove the tumor tissue completely by surgery because of the difficulty of discriminating between tumor tissue and healthy brain tissue.

But the technique developed by Dr. Eva Frei of the German Cancer Research Center and medical scientists at Heidelberg University is designed to improve such surgical procedures.

The scientists, noting tumors take up large amounts of the blood protein albumin, attached a fluorescent substance to albumin, which then enters the bloodstream and eventually accumulates in the brain tumor. Laser light is then used to cause the substance to glow, making the fine extensions of the tumor visible.

"Other contrast agents often fade, for tumor resection can take five to six hours," said Frei, but she said the fluorescence marker attached to albumin is visible during the entire operation. The scientists calculated the probability of the fluorescent tissue being tumor cells is 97 percent.

The study is reported in the journal Neurosurgery.