Glioblastoma Multiforme (GBM)
What is it?
Glioblastoma multiforme (GBM) is a malignant tumor of the brain. It is the most common primary intra-axial brain tumor with over 12,000 new cases per year. The average age of onset is 56 years old. The tumor grows within the brain tissue and microscopic cells spread across to distant parts of the brain. For this reason, the tumor is considered malignant.
GBM present with headaches (“H/A”-54% of patients), progressive neurologic deficit such as motor weakness (45%), and seizures (26%). H/A are usually worse in the morning; exacerbated by coughing, straining, bending forward; and associated with nausea and vomiting. Vomiting may make the H/A better temporarily. In 77% of brain tumor patients, H/A is similar to tension H/A, and in 9% migraine like. Most patients are symptomatic on average 5 months before seeking help. Neurologic deficits gradually worsen, unlike a stroke which presents suddenly. Any adult with first presentation of seizure should be suspected of brain tumor.
Neurologic findings are dependent on the location and size of the tumor. Motor weakness and discoordination are common; visual deficit (homonymous hemianopsia), personality change, difficulty with concentration, deterioration in work performance, and other more subtle findings are also seen. Papilledema is found with increased intracranial pressure.
Magnetic resonance imaging (MRI) with and without contrast demonstrates a ring enhancing lesion. Differential diagnosis includes metastatic tumor and early stroke; both can be difficult to distinguish from GBM by MRI. Either diagnosis can have substantial impact on prognosis and treatment options. Positron emission tomography (PET) scan can help, so can repeat MRI scanning and brain biopsy. Approximately 5% of GBM are multifocal.
Decadron 10 mg q6 hrs X 4 loading dose then 4 mg q6 hrs maintenance is started for brain swelling. Chemotherapy (BCNU and Temodar) is started after surgery and radiation.
Craniotomy (opening of the skull) is the preferred treatment for patients whose tumor can be “grossly” (visually, though not microscopically) resected. For those whose lesions are in eloquent regions of the brain, are in bad medical condition, elderly, or have poor quality of life, needle biopsy is recommended. Surgical implantation of Gliadel wafers (releases BCNU slowly over 2-3 weeks) have shown significant extension of survival. Surgical implantation of radio-isotope seeds also has benefit as does repeat gross total resection of recurrences.
Radiation therapy is recommended after surgery and may be combined with radiosurgery.
Outcome of Surgery
Gross total excision of the tumor with preservation of neurologic function is the goal. Longest survivals are associated with the most aggressive resections and repeat operations have beneficial effects. Survival times are doubled or greater with aggressive treatment. Once tumor extends into critical parts of the brain, gross subtotal resection has limited benefit. Tumor may extend into the corpus callosum to the other side of the brain and this is a poor indicator, usually resulting in expectant management. Recurrence of “ring enhancing tumor” on MRI after surgery may represent necrosis from radiation instead. Radiation necrosis can cause mass effect and require reoperation for diagnosis and treatment. Maintaining the highest level of function and quality of life is the ultimate goal of treatment. Studies have shown one year survival at 35%, two year survival at 10%. An aggressive, multi-specialty team approach affords the best outcome for patients with GBM.
We have the latest techniques and neurosurgical approaches available to us for your benefit. We take an aggressive approach to the treatment of Glioblastoma multiforme. We have the clinical experience for long survivals with a personal touch.