Surgery to Treat Brain Cancer
Surgery is the treatment of choice for accessible primary brain tumors, when the patient is in good health. The goal of surgery is to remove as much of the tumor as possible without damaging nearby normal brain tissue. The prognosis for patients with brain cancer improves when more than 90 percent of a tumor can be removed.
Removal is often complicated by the nature of the tumor (e.g., invasive, highly vascularized) and by its location. Partial removal (debulking) of the tumor can improve quality of life by alleviating symptoms and sometimes improve the effectiveness of radiation therapy or chemotherapy.
Before surgery, some important tests are performed. Patients over the age of 40 usually undergo an electrocardiogram (ECG or EKG) and a chest x-ray. Other tests are used to detect the presence of uncontrolled hypertension, diabetes, active coronary ischemia, or the presence of circulating anticoagulant (substance that inhibits normal blood clotting) in the blood. If any of these conditions are present, it may not be advisable to undergo craniotomy.
The goal of craniotomy is to remove as much of the tumor as possible. The procedure is performed under general anesthesia and involves opening the skull (cranium).
The neurosurgeon makes an incision into the scalp and several holes (called burr holes) are made in the skull. A bone saw is used to join the holes together to create a flap of bone.
The bone flap is then removed to expose the brain and remove as much of the tumor as possible. After the tumor has been partially or completely resected, the bone flap is replaced and secured using fine wire. Recovery from the procedure may take as long as 8 weeks.
Complications of craniotomy include bleeding (hemorrhage), swelling (edema), increased intracranial pressure (IICP), infection, and brain tissue damage.
In laser microsurgery, MRI is used to pinpoint the location of the tumor and a laser is used to destroy the tumor. This procedure may be used after craniotomy to remove remaining tumor tissue.
Brain-mapping is performed under local anesthesia and sedation. Electrodes stimulate nerves in the brain, measure responses, and allow communication with the patient. The surgeon removes as much of the tumor as possible without damaging vital areas of the brain, such as those that control motor function and speech.
In some cases, a chemotherapeutic agent called BCNU is used following surgery. In this treatment, the neurosurgeon places a wafer soaked with BCNU (Gliadel, BiCNU) into the surgical cavity after the tumor has been removed. By applying it directly to the diseased area of the brain, side effects are limited and the drug has a more beneficial effect.
Postoperative care includes drug therapy with corticosteroids, histamine inhibitors (block stomach acid), and antiepileptics. Corticosteroids (dexamethasone and Decadron) help reduce swelling and can relieve various postoperative neurological effects.
An MRI scan, with and without contrast, is often obtained to determine the extent of residual disease following surgery. Sometimes, a plan for rehabilitation is needed.