Fluorescence-guided surgery for brain cancers

Fluorescence-guided surgery (FGS) is a special way to help surgeons see brain tumors more clearly during surgery. FGS uses dyes that light up under special lights. These glowing dyes make cancer cells more visible, showing the difference between tumor tissue and healthy brain tissue. This helps surgeons remove more of the tumor while keeping healthy parts safe. FGS can make surgery safer and more effective.

In addition to brain cancer, FGS is used for cancers of the stomach, liver, lungs, breasts, bladder, prostate, colon and ovaries. FGS is sometimes used for children’s surgeries.

Other names for fluorescence-guided surgery include fluorescence image-guided surgery, fluorescence-guided resection and FGS.

In many surgeries, healthcare experts use images taken before the surgery from tests such as CT scans and MRI scans. Fluorescence-guided surgery (FGS) uses special dyes that glow in the body. These dyes stick to tissues such as cancer cells or lymph nodes, giving surgeons live images during the operation. This can help surgeons see the surgical area in real time, helping them remove cancerous tissue and leave healthy tissue.

Fluorescence-guided surgery is helpful for brain tumors such as glioblastomas, which can be difficult to remove completely. These tumors often grow into nearby healthy brain tissue. If any tumor is left behind, the cancer can grow back. FGS helps surgeons remove as much of the tumor as possible, which can help people live longer.

Before surgery, you take a special dye by mouth or through an IV in the arm. During surgery, surgeons shine a special light on the brain. The dye inside the tumor lights up and healthy brain tissue stays dark. This helps surgeons carefully remove the glowing tumor tissue while leaving healthy areas alone.

Dyes used in fluorescence-guided brain surgery

Several types of dyes may be used with fluorescence-guided brain surgery, including:

• 5-aminolevulinic acid, also called 5-ALA. This is a good dye for fluorescence-guided high-grade glioma surgeries. It is taken by mouth a few hours before surgery. The dye causes tumors to glow pink or red under a blue light.
• Fluorescein sodium (FNa). FNa also is used in brain surgeries. It is given through a needle in the arm, called an IV. This dye causes tumors to glow green under a yellow light.
• Indocyanine green (ICG). ICG is the most common dye in all types of fluorescence-guided surgeries. ICG is sometimes used to find tumors, but it is mainly used for blood flow imaging. It is given through a needle in the arm, called an IV. The dye glows green under a special light.

FNa, 5-ALA and ICG are all approved by the Food and Drug Administration. Research has shown these dyes to be safe and effective for fluorescence-guided surgeries.

Benefits of fluorescence-guided surgery for brain tumors may include:

• Better tumor removal. FGS can help take out more of the tumor.
• Improved survival. Patients may live longer when more of the tumor is removed.
• Fewer repeat surgeries. Removing more tumor the first time can lower the need for future surgeries.
• Real-time guidance. Surgeons can see tumor edges while doing surgery.

Possible risks of fluorescence-guided surgery may include:

• Sun sensitivity. Some dyes can make your skin sensitive to light for 24 hours. You must avoid sunlight and bright lights during that time.
• Allergic reactions. Side effects include skin rash or mild stomach issues. Rarely, people may have serious reactions if they are allergic to ingredients such as iodine, which is used in ICG dyes.
• Possible interactions with other medicines. Some blood pressure or heart medicines may cause side effects when combined with certain dyes. Tell your healthcare team about all the medicines and supplements you take before the surgery is scheduled.
• Mistakes in glow. Sometimes, healthy tissue may glow or tumor tissue may not. This can make it more challenging for surgeons to tell tumor tissue from healthy tissue.
• Short-term changes. The color of your skin or urine may change temporarily before the dye leaves your body.

Getting ready depends on the type of surgery and dye. Before the surgery, tell your healthcare team about any medicines or supplements you take.

You also may need to:

• Not eat or drink for a period of time before surgery.
• Get checked for possible allergies to the dye. Let your healthcare team know about any allergies you have.
• Sign a form saying you agree to use the dye.

Before surgery

How you prepare for surgery depends on the type of fluorescence-guided surgery you will have. You might get the dye a few hours or a day or more before surgery, depending on the type of dye. The 5-ALA dye usually is given by mouth. FNa and ICP are injected into your arm through an IV.

During surgery

As you prepare for surgery, your anesthesiologist or certified registered nurse anesthetist delivers the anesthesia medicines through an IV in your arm. Once you’re asleep, the anesthesiologist or nurse anesthetist may insert a flexible, plastic breathing tube into your mouth and down your windpipe. Use of the tube is to make sure that you get enough oxygen. It also protects your lungs from oral secretions or other fluids such as stomach fluids. The breathing tube is removed at the end of the surgery as you start to wake up.

A member of the anesthesia care team monitors you while you sleep. The team member adjusts your medicines, breathing, temperature, fluids and blood pressure as needed. Any issues that occur during the surgery are corrected with medicine and fluids. Rarely, a blood transfusion may be needed.

During surgery, the surgery team shines a special light on the brain. The dye inside the tumor lights up. Healthy brain tissue stays dark. This helps the surgeons carefully remove the glowing tumor tissue while leaving healthy areas alone. The surgeons can remove the tumor carefully, using the glow as a guide.

After surgery

After the surgery, you wake up slowly in the recovery room while a healthcare professional monitors you.

If you received 5-ALA dye, you’ll rest in a dark room for 24 hours because your eyes will be sensitive to light.

With all fluorescence dyes, the healthcare team monitors for side effects caused by the dyes, such as:

• Signs of allergy, including rash or swelling. If you have any signs of an allergic reaction, tell your healthcare team right away.
• Nausea or vomiting.
• Changes in skin color.

Your liver and kidneys will process the dye out of your system. It is flushed out of your body through urination and bowel movements.

Recovery is the same as other types of surgery. You may experience:

• Pain where the surgery was done.
• Muscle aches.
• Sleepiness.
• Blurry vision or dizziness.

Your healthcare team can monitor your pain and other side effects. Depending on the type of surgery, you may stay in the hospital for a few days. Healing after surgery may take time. Full recovery may take a few weeks. Your healthcare team can tell you if more tests or other follow-ups are needed. You might need more scans later, depending on your cancer type.

Scans such as CT scans or MRI are done before surgery, while FGS gives real-time images during surgery. This can help surgeons:

• See cancer edges more clearly.
• Remove the entire tumor more safely.
• Lower the chance of cancer coming back.
• Protect healthy body parts.
• Help with challenging cancers.
• Determine the next steps in your care.

Scientists are working to make these tools even better.