Glioma is a blanket term that refers to a brain tumor that develops from glial cells located within the brain, which support neurons with nutrients and oxygen and help maintain the blood-brain barrier. There are different types/grades of gliomas, based on the cell from which the tumor developed. Due to the variation of tumors, treatment is dependent on a few important variables, including a patient’s age, tumor grade (benign versus malignant), tumor size and location. Depending on the diagnosis, treatment plans involve a combination of surgery, chemotherapy, stereotactic radiosurgery at a Gamma Knife center or fractionated radiotherapy.
When it comes to glioma development, patients of all ages are at risk. Similar to most primary brain tumors, the exact cause is not well understood. However, one constant observation is that the risk of developing a glioma increases with age, and certain types of benign gliomas (ependymomas and pilocytic astrocytomas) tend to occur in children and young adults.
Types/Grades of Glioma
There are four grades of glioma, and the grades of gliomas are based on the type of glial cell the tumor originated from:
- Grade I – Pilocytic Astrocytoma: the most common in children, but it can occur in adults. Grows slowly and is relatively benign
- Grade II – Low-Grade Glioma: if not treated can recur and evolve into grade III or IV. Includes astrocytoma, oligodendroglioma and mixed oligoastrocytma
- Grade III – Malignant Glioma: more aggressive than grade II gliomas, full resection is difficult due to its behavior of invasive growth. Includes anaplastic astrocytoma, anaplastic oligodendroglioma, and anaplastic mixed oligoastrocytoma
- Grade IV – Glioblastoma Multiforme: the most aggressive and common type of primary brain tumor. Full resection is more difficult than grade III gliomas, and chance of recurrence is high
Symptoms of Glioma
Glioma symptoms can vary but can typically include:
- Nausea or vomiting
- Balance issues
- Muscular weakness
- Difficulty speaking
- Vision or hearing problems
- Change in personality including irritability
- Decline in brain function, including memory loss
Diagnosis of Glioma
A doctor will check your vision, hearing, balance, coordination, strength and reflexes during a neurological examination then order a computed tomography (CT) scan or a magnetic resonance imaging (MRI) scan. One of these two tests is often enough to indicate that a patient has a glioma. The scans also help determine the size, location and type of tumor. To confirm the diagnosis, a pathologist examines the tumor cells that will have to be obtained from a biopsy.
Treatment of Glioma
Glioma tumors vary greatly, which requires the doctor to establish a treatment plan that is appropriate for each individual case. Potential glioma treatment options include:
- Wait and See: This is an option for grade I tumors, small tumors or tumors located in non-accessible or vital areas where surgery is not an option.
- Glioma Surgery: Most patients require surgery, where the doctor will remove all or part of the glioma tumor depending on its grade, size, location and the patient’s health.
- Stereotactic Radiosurgery: For recurrence in rare cases, using specialized technology, such as the Leksell Gamma Knife®Icon™, the doctor delivers focused radiation directly to the tumor.
- Fractionated Radiotherapy: As the standard for treating gliomas, low level of radiation is delivered to a focused area around the glioma over many treatments, effectively shrinking the tumor.
- Chemotherapy: Temozolomide (temodar) is used for 6 to 12 months after radiation therapy is completed.