A glioma is a tumor that originates from the supportive glial cells of the brain or spinal cord. These tumors are the most common form of malignant brain tumor in adults and can occur at any age. When a glioma is diagnosed, surgical removal, known as a resection, is frequently the first step in treatment, involving a neurosurgeon operating to remove as much of the tumor as possible.
Goals of Surgical Resection
The principal objective of glioma surgery is to achieve a “maximal safe resection.” This means removing the largest possible amount of the tumor without harming healthy brain tissue that controls important functions. When a tumor cannot be entirely removed because it is near important brain structures, a surgeon will perform a subtotal resection.
Another goal is to obtain a tissue sample for pathological analysis. A pathologist examines this biopsy to determine the specific type of glioma and its grade, which indicates how aggressive it is. This diagnosis is necessary for guiding the subsequent stages of treatment.
Surgery also relieves neurological symptoms caused by the tumor’s mass effect. As a glioma grows, it can press on the brain, leading to headaches, seizures, or cognitive changes. By removing the tumor mass, the pressure inside the skull is reduced, which can lead to a significant improvement in these symptoms.
The Glioma Resection Procedure
Neurosurgeons develop a detailed plan using advanced imaging technologies well before the operation. Functional MRI (fMRI) is used to map brain activity, identifying areas responsible for speech and sensation, while Diffusion Tensor Imaging (DTI) visualizes the brain’s white matter tracts. This pre-operative mapping allows the surgeon to plan the safest route to the tumor.
The surgery is performed through a craniotomy, a procedure where a section of the skull is temporarily removed to access the brain. To improve safety and precision, several advanced intraoperative technologies may be employed. One technique is intraoperative brain mapping, where the surgeon uses small electrodes to stimulate the brain’s surface to identify and avoid functional areas during resection.
In cases where a tumor is near brain regions controlling speech or motor function, an awake craniotomy might be performed. The patient is awakened during a portion of the surgery and asked to perform tasks like speaking or moving their limbs. This provides real-time feedback to the surgeon, ensuring that eloquent cortex—brain tissue with an identifiable function—is not damaged.
To better distinguish tumor from healthy brain tissue, surgeons may use fluorescence-guided surgery. The patient drinks a solution containing 5-aminolevulinic acid (5-ALA) hours before the procedure. Tumor cells absorb this compound and glow under a specialized blue light, making them easier to remove. Some hospitals are also equipped with intraoperative MRI (iMRI), allowing the team to take new scans during the operation to assess how much tumor has been resected.
Surgical Risks and Potential Complications
Any brain surgery carries a set of general risks, including the possibility of infection, bleeding, blood clots from inactivity, and adverse reactions to anesthesia. These complications are not specific to glioma surgery but are potential outcomes of any major operation. The medical team takes extensive precautions to minimize these risks.
More specific to glioma resection are the neurologic risks, which are highly dependent on the tumor’s size and its location within the brain. The primary complication is the potential for new or worsened neurological deficits. For instance, a tumor near the nerves connected to the eyes could lead to vision loss, while operating near areas responsible for language can result in aphasia.
Other potential neurologic complications include weakness or paralysis in the limbs if motor pathways are affected, as well as changes in sensation or coordination. Cognitive functions, such as memory and executive function, can also be impacted. The surgical team’s use of advanced pre-operative and intraoperative mapping techniques is designed to reduce the likelihood of these outcomes.
Recovery and Post-Operative Care
Following a glioma resection, patients are monitored closely in an intensive care unit (ICU) or a specialized neurosurgical unit. This allows the medical team to watch for complications, such as swelling in the brain. Headaches and significant fatigue are common during the first few days and weeks, and patients often return home within a week.
A few weeks after the procedure, a post-operative MRI is performed. This scan helps the medical team assess the extent of the resection and see how much of the tumor was successfully removed. It also serves as a new baseline for monitoring the tumor site for any signs of recurrence.
For some individuals, rehabilitation is an important part of recovery. Depending on the location of the tumor and the effects of the surgery, patients may need support from various therapists. Physical therapy can help restore strength and mobility, occupational therapy can assist with daily living activities, and speech therapy can address any language difficulties. The recovery process is highly individualized.
The Role of Resection in Overall Treatment
Surgical resection is a component of a comprehensive glioma treatment plan, but it is often the beginning of the therapeutic process. While surgery can sometimes be the only treatment needed, it is rare for resection alone to be a complete cure, particularly for high-grade gliomas. Microscopic tumor cells almost always remain in the surrounding brain tissue.
Based on the pathological analysis from the surgery, a multidisciplinary team, including neuro-oncologists, will recommend a plan for adjuvant therapies. These are additional treatments designed to target and destroy any cancer cells left behind after surgery.
The most common adjuvant therapies following glioma resection are radiation therapy and chemotherapy. Radiation therapy uses high-energy beams to kill cancer cells, and it is often combined with chemotherapy drugs that travel through the bloodstream to target tumor cells. This multi-modal approach is the most effective strategy for managing gliomas.