Glioma Treatment: What are the Options?
- Surgery is often the first step in glioma treatment, aiming for maximal safe resection (removal of the tumor) while preserving essential brain function.
- Depending on how surgery goes and other risk factors, additional treatment, such as radiation, chemotherapy, or targeted therapy, may be recommended.
- Radiation therapy targets residual cancer cells, especially in higher-grade tumors or if surgery leaves microscopic disease behind.
- Chemotherapy (like Temozolomide or PCV) and targeted therapies can help control or slow tumor growth when surgery or radiation alone isn’t sufficient.
- IDH inhibitors, such as Vorasidenib, represent a major breakthrough for certain gliomas, offering a new option to delay or avoid more intensive treatments.
“Over the years, it’s very exciting when we have a new therapy. The identification of IDH mutation probably occurred 10 years ago … and we began to differentiate that there was a survival advantage if you harbored this mutation,” Dr. Burt Nabors, a neuro-oncology expert at University of Alabama Birmingham (UAB) Medicine in Birmingham, Alabama, tells SurvivorNet.
Read MoreGlioma Grade Matters
Gliomas are considered “primary” brain tumors because they start in the brain or spinal cord itself, rather than spreading from another part of the body. They account for about a quarter of all primary brain and spinal cord tumors and can be either slow-growing (low-grade) or more aggressive (high-grade).- Low-grade gliomas (Grade 1 or 2): These typically grow slowly but can still cause significant problems, depending on where they are located.
- High-grade gliomas (Grade 3 or 4): These tend to grow more quickly and often come with a higher risk of returning after treatment. Glioblastoma multiforme (GBM) is the most common and aggressive form of high-grade glioma (Grade 4).
Surgery: Often the First Step
Surgery is frequently the first line of defense against gliomas. The goal is to remove as much of the tumor as safely possible—a procedure often referred to as a “maximal safe resection.” Neurosurgeons aim to remove visible tumor tissue without damaging the surrounding healthy brain areas that control speech, movement, and other critical functions.
The tumor’s position in the brain can determine whether a full surgical removal is possible or if a more limited operation or even just a biopsy (obtaining a small tissue sample) is safer.
If surgery is successful, it may be the only treatment necessary for a time.
“If we look at our standard treatment options, if it’s a good resection, we would observe these people,” Dr. Nabors says.
What to Expect from Surgery
Modern surgical techniques allow doctors to map critical brain functions during the operation (such as speech or motor skills) to minimize complications. This might involve:
- Intraoperative Functional Mapping: Identifying the exact areas of the brain responsible for key functions.
- Stereotactic Neuro-Navigation: Using 3D imaging to guide the surgeon precisely to the tumor.
For some patients, these technologies mean shorter hospital stays and faster recoveries. But even if a surgeon removes all visible tumor on an MRI, many gliomas have cells that extend beyond the identifiable edges. That’s why doctors often recommend additional treatments, like radiation or medication, afterward.
Radiation Therapy: Targeting What’s Left Behind
Radiation therapy uses high-energy beams (often X-rays) to damage cancer cells’ DNA, preventing them from growing and dividing. Because gliomas often infiltrate normal brain tissue, radiation can be vital for targeting leftover microscopic tumor cells after surgery. In some situations—especially if the tumor cannot be removed safely by surgery—radiation may serve as the primary treatment.
Before beginning radiation, patients undergo a “simulation” session, which involves a specialized CT scan and possibly wearing a custom-fitted mask to keep the head still during treatment. This helps the radiation oncology team design a precise plan.
Treatment typically occurs five days a week over several weeks, delivering small “fractions” of radiation to allow healthy cells to recover.
Possible side effects include:
- Fatigue: The most common side effect, which can build over the course of treatment
- Skin Changes: Redness or irritation on the scalp where radiation enters
- Hair Loss: Often occurs at the treatment site; depending on dose and location, hair may or may not grow back fully
- Long-Term Risks: Rare but serious, such as cognitive decline or “radiation necrosis” (damage to healthy tissue).
Despite these potential side effects, radiation remains a crucial tool for controlling glioma growth and reducing the chance of recurrence.
Balancing Surgery & Radiation
Deciding on surgery, radiation, or a combination of both involves multiple considerations. Since low-grade gliomas grow more slowly, they may not require immediate radiation if most of the tumor is removed during surgery. In contrast, high-grade gliomas often need radiation therapy soon after surgery.
This personalized approach highlights the need for a team of specialists—such as neurosurgeons, radiation oncologists, and neuro-oncologists—to determine the most appropriate treatment plan for each patient.
Chemotherapy
Because even the most extensive surgery and precise radiation cannot always eradicate every glioma cell, many patients also receive chemotherapy.
Common regimens include:
- Temozolomide (TMZ): This is an oral drug often used alongside radiation in high-grade gliomas (such as glioblastoma) and sometimes for low-grade gliomas when needed. TMZ can cross the blood-brain barrier effectively.
- PCV (Procarbazine, Lomustine, Vincristine): This is a more intensive regimen sometimes recommended post-radiation for certain low-grade gliomas, especially those with genetic features (like 1p/19q co-deletions) that respond well to this combination.
“PCV is a very difficult treatment regimen for patients to tolerate,” says Dr. Ashley Ghiaseddin, a neuro-oncologist at University of Florida Health. “Frequently, patients forego the vincristine, or the ‘V’ of the PCV regimen.”
Doctors weigh factors such as a patient’s age, overall health, and molecular markers within the tumor to decide which chemotherapy (if any) is appropriate.
IDH Inhibitors: A New Option for Some Patients
After decades with few advances in glioma treatment, a significant breakthrough arrived with Vorasidenib (brand name Voranigo)—a dual inhibitor targeting IDH1 and IDH2 mutations. IDH mutations are commonly found in certain low-grade gliomas. By blocking these mutated enzymes, Vorasidenib helps slow or stop tumor growth.
IDH1 and IDH2 are enzymes involved in cell metabolism. When mutated, they can drive cancer growth.
Vorasidenib is approved for adults and children over 12 with IDH-mutant, Grade 2 glioma that has recurred or is hard to remove with surgery alone.
In clinical studies, Vorasidenib improved progression-free survival—meaning patients went longer before the tumor grew back or needed another treatment. It also successfully crosses the blood-brain barrier, which is often a hurdle for cancer drugs.
Doctors typically consider IDH inhibitors in place of—or before—radiation and chemotherapy in eligible low-grade glioma patients to delay more intensive treatments (like radiation) and their potential long-term side effects.
Choosing the Right Treatment Path
The treatment path for glioma depends on the grade and several other factors.
Here’s a breakdown of what to expect for each grade:
- Grade 1 glioma: Sometimes surgery alone is enough, especially if the neurosurgeon can remove the entire tumor.
- Grade 2 glioma: These may require observation, IDH inhibitors (if a mutation is detected), or chemotherapy and radiation if the tumor is large or partially removed.
- Grade 3 or 4 glioma: More advanced gliomas often require a combination of surgery, radiation, chemotherapy, and possibly other targeted therapies.
Location is another critical factor; a glioma near essential brain areas may limit how much can be removed safely. This influences whether the next step is observation, radiation, chemotherapy, or a targeted approach.
Risk Assessment and Follow-Up
After the tumor is removed, a pathologist evaluates its grade, molecular profile (IDH mutations, 1p/19q co-deletions, MGMT promoter status, etc.), and other features. Your care team will then discuss your risk of recurrence. Age (particularly over 40), incomplete resection, tumor size, and severe neurological symptoms can place someone in a higher-risk category, making additional therapies more urgent.
Questions to Ask Your Doctor
- Will surgery be the first step in my treatment process?
- How will I be monitored after surgery?
- What are the risks of undergoing surgery for glioma?
- What side effects might I experience afterwards?
- When should I undergo molecular testing?
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