Fluorescent Imaging for Brain Tumor Surgery
Fellowship-trained brain tumor surgeons • 12 hospital affiliations across New Jersey
Fluorescent imaging using 5-aminolevulinic acid (5-ALA) is an intraoperative technique in which a patient with a suspected high-grade brain tumor drinks a liquid medication several hours before surgery. Tumor cells preferentially convert 5-ALA into a fluorescent compound (protoporphyrin IX) that glows bright pink under violet-blue light viewed through the operating microscope, while normal brain tissue remains dark. This visual distinction helps surgeons identify residual tumor and maximize safe tumor removal.
Key takeaways
- 5-ALA fluorescence makes many high-grade gliomas visibly distinct from normal brain tissue under violet-blue light, improving the surgeon's ability to identify residual tumor.
- Randomized clinical trials have shown that 5-ALA–guided surgery increases the rate of complete tumor resection compared with conventional white-light microsurgery.
- More complete tumor removal has been associated with longer progression-free survival and may improve overall survival in appropriately selected patients.
- Atlantic Brain and Spine incorporates fluorescence-guided imaging as part of a comprehensive surgical strategy for appropriately selected malignant brain tumors.
- 5-ALA (Gliolan®) is FDA-approved to assist in the intraoperative visualization of suspected high-grade glioma tissue.
| Agent | 5-aminolevulinic acid (5-ALA, marketed as Gliolan®) |
| FDA approval | Approved to assist in the intraoperative visualization of suspected high-grade glioma tissue |
| Administration | Oral medication taken approximately 3 hours before surgery |
| Mechanism | Tumor cells preferentially convert 5-ALA into fluorescent protoporphyrin IX (PpIX), which glows pink under violet-blue light (405 nm) |
| Best suited for | Suspected high-grade gliomas; selected additional malignant brain tumors may also demonstrate fluorescence |
| Primary benefit | Improves visualization of tumor tissue and increases the likelihood of complete tumor resection in appropriately selected patients |
Timing and stay vary by patient and complexity. Your surgeon will confirm what to expect in your case.
How 5-ALA fluorescence works
5-ALA is a naturally occurring amino acid and a precursor in the heme biosynthesis pathway. When taken orally before surgery, it is absorbed and distributed throughout the body. In normal cells, 5-ALA is efficiently metabolized. In malignant glioma cells, however, this pathway is dysregulated, causing protoporphyrin IX (PpIX), a fluorescent compound to accumulate preferentially within tumor cells.
In the operating room, the neurosurgeon switches the surgical microscope to violet (405 nm) illumination. Under this light, malignant tumor cells fluoresce bright pink or red, while normal brain tissue appears dark blue. The surgeon uses this visual contrast to identify and remove fluorescent tumor at the margins areas that often appear identical to normal brain under standard white light.
This technique is particularly valuable at the infiltrating edge of glioblastoma, where microscopic extensions of tumor spread beyond the visible enhancing mass into surrounding brain tissue.
Clinical evidence and outcomes
The landmark randomized controlled multicenter trial by Stummer and colleagues compared 5-ALA fluorescence-guided surgery with conventional white-light microsurgery for malignant gliomas.
Key findings included:
- A significantly higher rate of complete contrast-enhancing tumor removal with 5-ALA guidance.
- Improved progression-free survival at six months compared with white-light surgery.
- No increase in permanent neurological deficits when fluorescence guidance was incorporated into careful microsurgical decision-making.
Since that landmark study, multiple clinical series and real-world experience have confirmed these findings. Today, fluorescence-guided surgery is incorporated into international treatment guidelines for appropriately selected patients with suspected high-grade glioma.
Benefits and risks
Potential benefits
- Significantly higher rate of complete tumor removal compared to white-light surgery
- Extends progression-free survival in glioblastoma
- Provides real-time visual guidance without relying on imaging that may not reflect intraoperative anatomy
- No additional surgical incision or instrumentation the 5-ALA is taken orally before surgery
Possible risks
- Phototoxicity skin and eye sensitivity to bright light for 24 hours after surgery; patients must avoid direct sunlight
- Mild and transient liver enzyme elevation -- resolved in most patients; not clinically significant
- False-negative fluorescence in low-grade or necrotic tumor regions 5-ALA most reliably highlights actively dividing malignant cells
- Not specific to glioma other highly metabolic tissues can fluoresce; requires experienced interpretation
Your surgeon will review the benefits and risks specific to your diagnosis during your consultation.
What recovery looks like
Fluorescent imaging is incorporated into brain tumor surgery and does not require a separate recovery period. Recovery follows the standard craniotomy timeline, with one additional precaution related to temporary light sensitivity after taking 5-ALA.
- Day of surgery Patients should avoid direct sunlight and bright indoor lighting for approximately 24 hours after receiving 5-ALA because of temporary skin and eye photosensitivity.
- Days 1 to 3 Standard post-operative craniotomy recovery. A post-operative MRI is typically obtained within 24 to 48 hours to evaluate the extent of tumor resection.
- Weeks 1 to 4 Gradual return to light activity. Steroids are tapered and anti-seizure medication is adjusted as appropriate.
- 4 to 6 weeks Follow-up with neurosurgery, neuro-oncology, and radiation oncology to finalize the postoperative treatment plan based on pathology and molecular testing.
Frequently asked questions
Does 5-ALA work for all brain tumors?
No, 5-ALA most reliably highlights high-grade gliomas, including glioblastoma (GBM), anaplastic astrocytoma, and anaplastic oligodendroglioma. Low-grade gliomas, meningiomas, and many brain metastases typically do not fluoresce as brightly or consistently, although some metastatic tumors and meningiomas may demonstrate fluorescence. Your surgeon will determine whether 5-ALA is likely to be helpful based on your specific diagnosis and imaging findings.
Can 5-ALA cause an allergic reaction?
Allergic reactions to 5-ALA are rare. Patients with a known porphyria (a group of disorders involving the heme biosynthesis pathway) should not receive 5-ALA. Routine pre-operative screening identifies patients who are not candidates.
What does the tumor look like under fluorescent light?
Under the violet illumination of the surgical microscope, areas of active high-grade tumor glow bright pink or magenta against the dark blue-gray background of normal brain tissue. The fluorescence is visible to the surgeon in real time during resection, guiding the removal of tissue right up to the point where the pink signal disappears.
Is fluorescent imaging used at all brain tumor centers?
No, Fluorescence-guided surgery requires specialized equipment, including a fluorescence-capable operating microscope, access to 5-ALA (Gliolan®) and experience interpreting fluorescence during surgery. It is generally available at specialized brain tumor centers. Atlantic Brain and Spine has incorporated fluorescence-guided surgery into its brain tumor program for appropriately selected patients.
This page is for general education and does not replace medical advice. Treatment decisions should be made with a qualified neurosurgeon based on your individual diagnosis and imaging. To discuss your options, call Atlantic Brain and Spine Brain Tumor Care at 973.993.7100 or request a consultation.
Fluorescence-Guided Brain Tumor Specialists at Atlantic Brain and Spine
Your care is provided by Atlantic Brain and Spine's multidisciplinary brain tumor team, including fellowship-trained brain tumor neurosurgeons who collaborate closely with the neuro-oncology team at the Gerald J. Glasser Brain Tumor Center.
