Brain Tumors

When Senator Edward Kennedy recently succumbed to a brain tumor,  it brought new attention to a very formidable condition. Brain tumors attack both children and adults.  There are more than 120 types and they are extremely difficult to diagnose.  Location of the tumor determines which symptoms manifest, possible treatment options and prognosis. Many brain tumors mimic other neurological disorder symptoms. Once a tumor is diagnosed and a pathology report done, it is then necessary to find an appropriate treatment center, develop a customized treatment plan and determine a prognosis for the patient.

Symptoms of a Brain Tumor 

Brain tumor symptoms vary. The location, size, type and stage are all factors determining which symptoms one might experience. Common possible symptoms include new seizures in adults, gradual loss of movement or sensation in a limb, unsteadiness, loss of balance, confusion, disorientation, memory loss, loss of vision or hearing, behavioral changes, headaches, nausea, speech difficulty, stroke, fainting, etc. All are symptoms seen in various diseases which can mislead a doctor trying to make a diagnosis. This makes diagnostic testing extremely important to determine what is happening to a patient presenting any of these symptoms.

Diagnosis

Diagnosis is normally done in three parts. The first part is the initial neurological exam.  This exam evaluates which areas of the neurological system are involved. The doctor checks for limb weakness, paralysis, loss of sensation, and loss of minor and gross motor control in various ways.  Sometimes just an exam is enough for referral for a scan, other times the doctor may do an evoked response test or other testing before ordering a scan.  The second part is the scan.  There are three distinct types of scans available and the individual doctor determines which scan needs done.  The MRI or magnetic resonance imaging scan is a three dimensional image made from detecting signals emitted from normal and abnormal tissue. This scan shows clear imaging of tumors with pictures of various levels of the brain put together to form three dimensional images. The CT scan or CAT scan, computed tomography, is done using iodine as a contrast agent.  Swelling, bleeding, bone and tissue calcification are shown clearly. This scan shows soft tissue, blood vessels and bone.  The third type of scan is the PET, Positron Emission Tomography.  The PET is a clear picture of the brain's activity where the other scans are of the brain's structure.  For the PET scan, one is given glucose with radioactive markers in the glucose.  The scan then measures the rate of absorption of the glucose into the suspected tumor and actively records and produces a live image showing differences between scar tissue, necrosis and recurring tumor cells. The PET scan is used not for diagnosis as much as for follow up determinations of success of treatments. 

After the neurological exam and scan, the next step is a biopsy.  Biopsies are done two ways. The location of the tumor determines whether an open or closed biopsy is best.  An open biopsy is done with a craniotomy - a piece of skull is removed to gain access to the brain.  The surgeon then resects or debulks the tumor and the skull piece is replaced.  A closed biopsy is a stereotactic or needle biopsy and done by drilling a small hole in the skull. A long needle is then inserted and guided into the tumor. Once in the tumor, a sample of tissue is extracted through the needle. The extracted tissue is then sent to a pathologist to examine and report on to the doctor.

A new technique for biopsy and surgery for skull base tumors is being performed at the Skull Base Institute.  This breakthrough technology is only performed there, but shows remarkable promise and involves minimally invasive endoscopic techniques.  As progress is made in perfecting this technique, it will become available at other centers and more types of brain tumors will become accessible and treatable with improved survivability prospects.

Types of Brain Tumors and Treatment

There are over 120 different types of brain tumors.  Some more prevalent in children than in adults.  Brain stem glioma, medullobastoma, Juvenile Pilocytic Astrocytoma, pineal tumor, and optic nerve gliomas are a few of them.  While some of the more frequently diagnosed types in adults are acoustic neuroma, chordoma, astrocytoma, CNS lymphoma, craniopharyngioma, and the whole family of gliomas. These mentioned are but a few of the many diverse types and subtypes. The World Health Organization has developed a classification system to identify types (by cell origin and behavior) and grade (rate of growth).

Once a pathology report is completed; the type, grade and location of the tumor determined; and second opinions evaluated, it is time to decide a course of treatment. Different facilities offer different types of treatment procedures. Your physician will help you with these decisions.  Most brain tumors require surgery for removal or partial removal. Once surgery is completed the next courses of treatment are normally chemotherapy and radiation therapy. Some tumors do not require surgery, while others are inaccessible for surgery and can only rely upon chemo and radiation.  Many are treated successfully with just chemo and radiation. Others are unsuccessful with surgery, chemo and radiation therapy combined.

Prognosis

The prognosis is unique to the individual, the tumor, treatment, and other factors. Brain tumors in children are the most commonly diagnosed form of cancer after leukemia, also the most common form of cancer death in children after leukemia. Yet this only represents 4-5 percent (of 100,000) which translates into 95-96 percent of survivable brain tumors in children. With survival comes new challenges. New educational needs, lack of motor skill abilities and physical challenges are common results from portions of the brain being removed or due to necrosis by radiation. Adults survivability rates are not as high but average about 80 percent.

More information on symptoms, treatments, facilities, physicians and statistics are available through the American Brain Tumor Association, the National Brain Tumor Society, the World Health Organization, Center for Disease Control and the Skull Base Institute.