Meningiomas are typically slow-growing, noncancerous tumors that form in the membranes that surround the brain on the inside of the skull. People with meningiomas generally have a good prognosis, but even the most benign forms can regrow after treatment and become problematic and even life threatening. Grade I (benign) meningiomas can be managed with surgery and/or radiotherapy, but there is a risk of tumors coming back (recurring), particularly if they are not completely removed. Grade II (atypical) and grade III (anaplastic or malignant) tumors are more likely to recur after treatment.
The neurosurgeons, neuro-oncologists, and radiation oncologists at Memorial Sloan Kettering have deep experience in managing meningiomas at all stages. We see patients from all over the world with the most difficult brain tumor cases, including meningiomas. Our doctors try to help relieve patients’ symptoms and to slow or stop the advance of these resistant tumors using surgery, radiation, and drug therapies.
Our treatment approaches include:
- MRI-guided microneurosurgery
- Stereotactic radiosurgery (SRS)
- Image-guided radiation or re-irradiation
- Proton radiotherapy
- Targeted-drug therapy and chemotherapy
Surgery for Meningioma
Meningiomas can occur anywhere along the skull lining. The tumor’s location largely determines how complex a surgery will be. Tumors lying over the top of the brain can be straightforward to remove surgically, while those at the skull base can require hours of surgery by teams of surgeons. Such complicated surgeries often demand difficult maneuvers around and through skull bones. As a result, sometimes not all of the tumor can be removed. This is especially true if there is involvement of important arteries, veins, and cranial nerves, or even invasion into the brain itself. All of these problems are amplified for tumors that have regrown.
Surgeons knowing what to expect is crucial to the success of an operation. At MSK, we use a range of sophisticated imaging techniques, including magnetic resonance imaging (MRI), to help visualize tumors before a surgery. This imaging can be combined with a computerized view of the brain to help surgeons figure out how much of the tumor is accessible, and whether there are risks to brain function.
MSK neurosurgeons devote themselves solely to the removal of brain tumors, so they have vast experience with meningiomas, both newly diagnosed and recurrent. They have access to the most advanced imaging equipment, the best intraoperative navigation equipment, state-of-the-art surgical microscopes, and even an MRI scanner right in the operating room to evaluate on the spot whether more of the tumor can be removed safely. Postoperative care at MSK, provided by our expert nursing staff, is second to none.
Sometimes the treatment of recurrent meningiomas includes brachytherapy, the implantation of radioactive sources directly into the tumor. Our doctors work closely with MSK’s radiation oncologists to select patients for this therapy. Radiation oncologists and medical physicists plan the treatment in advance and come to the operating room to help us implement it.
Radiation for Meningioma
Radiation therapy can be used in several ways for meningiomas. It may be recommended as additional therapy after surgery to prevent regrowth of a tumor, depending on its location and grade. Radiation may also be used as the sole treatment of a meningioma in a location not appropriate for surgery. Radiation may also be used if a meningioma regrows after surgery. Repeat radiation is given occasionally for new meningiomas that are in a different location than the initial tumor, or even to the same site of the initial tumor.
Radiation has been used to treat meningiomas for many years, but our ability to deliver radiation therapy has greatly improved. Radiation therapy is now more directed to the tumor, sparing the nearby healthy tissues. This improvement comes from a better understanding of tumors based on MRI and high-definition computed tomography (CT) scans, and improvement in radiation planning technology and delivery. We also use imaging on our radiation machines to verify within millimeters that the setup for each patient is accurate and can be reproduced from treatment to treatment. These techniques allow more precise targeting and delivery of radiation, leading to improved results.
The most common schedule of radiation therapy is a daily treatment of a low dose of radiation delivered over five to six weeks. This is well tolerated by most patients and is less likely to harm nearby normal tissue than larger, individual doses of radiation.
For recurrent or regrowing meningiomas, we will occasionally use repeat radiation therapy. This requires special expertise and an understanding of potential long-term effects. Repeat radiation therapy is sometimes given with a low, daily dose over five to six weeks, and sometimes with a shorter but more intense course of radiation therapy. Brachytherapy is sometimes used as well. In this kind of therapy, which happens at the time of surgery, doctors put a source of radiation in the area from which the tumor was removed.
The most common form of radiation delivery is external-beam radiation, in which radiation is delivered from a machine called a linear accelerator that creates radiation similar to that used in diagnostic x-ray. External-beam radiation can be designed to be very precise, in a treatment called intensity-modulated radiation therapy.
On occasion, we also use proton therapy, another form of external-beam radiation. This is most frequently used for meningiomas that are deep in the brain, or occasionally for re-treatment. When we recommend treatment with proton therapy, we use a facility in New Jersey that has a special machine, a cyclotron, to produce protons. We are also building a proton facility in northern Manhattan, projected to open in 2018.
All of these techniques and treatment approaches require the input of an experienced, multidisciplinary staff composed of radiation oncologists, neuro-surgeons, neuro-radiologists, neuro-pathologists, neuro-oncologists, and medical physicists. Our meningioma team has all of these specialists, and we meet routinely to review and discuss optimal treatment for each patient.
Drug Therapy for Meningioma
Unfortunately, despite surgery and radiation, a small number of meningiomas may grow back and require chemotherapy or some other form of medical therapy. At MSK, our team is investigating new and improved ways of delivering these therapies to patients. We sequence individual patients’ meningioma genomes, in hopes of determining the molecular mechanisms of tumors. The goal is to create a personalized treatment plan based on each individual’s tumor and situation. This may include traditional chemotherapy, molecularly targeted therapy, immunotherapy, or participation in a clinical trial.
For a list of available clinical trials for meningioma, visit our clinical trial finder.