Color distinguishes tumor from healthy tissue to improve tumor removal
The imaging agent 5-Aminolevulinic Acid (5-ALA), which helps neurosurgeons see the edges of a tumor more clearly to improve removal, was used in brain cancer surgery at University Hospitals Seidman Cancer Center today for the first time since the FDA approved it for use in the United States. Although the drug has long been a standard of care in Germany and much of Europe, it was only approved by the FDA for use in the U.S. in 2017.
Andrew Sloan, MD, Director, Brain Tumor and Neuro-Oncology Center at UH Seidman and UH Cleveland Medical Center, who has been doing clinical trials with the drug for almost a decade based on his own FDA-approved IND clinical trial, was the first neurosurgeon in the U.S. to use the drug on a patient with brain cancer since FDA approval.
Several published studies — including those from Dr. Sloan -- have shown that removing more tumor results in improved survival. However, this often is difficult.
“Glioblastoma are tumors which derive from the brain itself. They look like brain tissue, they feel like brain tissue, and at times, it’s hard to determine where tumor ends and inflamed brain tissue begins,” said Dr. Sloan.
To help identify the difference between the border of tumors and healthy tissue and improve tumor removal, Dr. Sloan used 5-ALA during surgery so that the tumor cells glowed hot pink when illuminated with a special blue light incorporated into his operating microscope.
This novel technique enabled him to see the edges of the tumors more clearly, allowing him to remove them more completely from the brain.
Patients take the drug by mouth prior to surgery, and then during their operation, Dr. Sloan uses the blue light to identify and remove tumor cells, a process called fluorescence guided resection (FGR).
Compared to normal tissue, many brain tumors metabolize 5-ALA to a fluorescent compound called Protoporphyrin IX, a structure similar to that of chlorophyll found in plants. Tumors that have high levels of this compound fluoresce (glow) when exposed to blue light. Using a specially modified surgical microscope that emits the blue light enables Dr. Sloan to see the glowing tumor tissue and help guide excision of the tumor.
“If we get out 95 to 99 percent of the tumor, we can essentially double the patient’s survival,” said Dr. Sloan, who holds the Peter D. Cristal Chair in Neurosurgery at UH
“Nearly 13,000 people are diagnosed each year in the U.S. with malignant gliomas. Unfortunately, cures are rare and most patients live less than 2 years, so improved treatment options are critical,” said Dr. Sloan.
A video showing how ALA lights up the tumor can been seen at: https://www.gleolan.com/
Article originally posted as UH Press Release, October 15, 2018