Fluorescence-Guided Resection With 5-Aminolevulinic Acid May Improve Glioma Survival

Alicia Ault

April 19, 2005

April 19, 2005 (New Orleans) — Interim results of a multisite phase 3 study presented here yesterday show that fluorescence-guided surgery with 5-aminolevulinic acid (5-ALA) appears to increase progression-free survival in malignant glioma.

Five-ALA, which is not approved in the U.S., causes the accumulation of fluorescent porphyrins in malignant gliomas, which may help surgeons identify and resect tumors intraoperatively.

Walter Stummer, MD, vice chairman of neurosurgery at the University of Dusseldorf in Germany, presented data on behalf of the ALA-Glioma Study Group at the American Association of Neurological Surgeons annual meeting. Eighteen centers in Germany participated.

"This study addresses the basic controversy in neurosurgery on whether maximal cytoreductive therapy of malignant gliomas is of benefit to patients," said Dr. Stummer. He added that the results of the study "demonstrate that fluorescence guidance using 5-ALA enhances resections of malignant gliomas, and that enhanced resections are beneficial by translating into longer progression-free survival."

The cumulative six-month progression-free survival rate for the first 270 patients was 41% for the 5-ALA group compared with 21% for the control group. Although the trial was not powered to show any difference in overall survival, patients in the fluorescence-guided group had a median survival of 15.2 months compared with 13.5 months in the control group.

For the study, 350 patients were randomized to fluorescence-guided resection (with 20 mg/kg of body weight of 5-ALA given three hours before induction of anesthesia) or conventional microsurgery (with white light). Dr. Stummer said the surgery was conducted using identical microscopes.

Magnetic resonance imaging (MRI) was done preoperatively, intraoperatively, and on days 1-3, day 7, week 6, and every three months thereafter.

In the 5-ALA group, 65% of postoperative MRIs were devoid of residual contrast-enhancing tumor compared with 36% of the control group ( P < .001). Patients who showed less contrast in their MRIs also had longer median survival — 16 months compared with 12 months in the control group ( P < .001).

There was no difference in neurologic status or Karnofsky Performance Scale between the two groups. Peter Black, MD, chief of neurosurgical oncology at Dana Farber Cancer Institute in Boston, Massachusetts, said that Dr. Stummer's study had provided class I evidence of improved survival. While the data are exciting, 5-ALA is not yet approved in the U.S., and there is still a continuing need for other treatments, he added.

The study was sponsored by the German company Medac gmbh, which makes 5-ALA.

AANS 2005 Annual Meeting: Abstract 708. Presented April 18, 2005.

Reviewed by Gary D. Vogin, MD