Brain Tumors

Brain tumors are classified into two main groups: primary and metastatic.

• Primary brain tumors originate from the tissues of the brain, or the brain's immediate surroundings, and are categorized as:
  • Glial (composed of glial cells) or non-glial (developed on or in the structures of the brain, including nerves, blood vessels, and glands) and as
• Benign (harmless) or Malignant(harmful, aggressively malicious).

• Metastatic brain tumors begin somewhere else in the body (such as the breast or lungs) and migrate to the brain, usually through the bloodstream. Metastatic tumors are considered cancerous and are malignant.

Metastatic brain tumors affect nearly one in four patients with cancer, or an estimated 150,000 people a year. Up to 40 percent of people with lung cancer will develop metastatic brain tumors.

In the past, the outcome for patients diagnosed with these tumors was very poor, with typical survival rates of just several weeks. Today using more sophisticated diagnostic tools, along with innovative surgical and radiation approaches, survival rates have expanded to years, and improved quality of life is a possibility for patients.

Pediatric brain tumors are different from adult brain tumors.

• Pediatric brain tumors typically come from different tissues in the body.
• Some types of brain tumors are more common in children than in adults. The most common types of pediatric tumors are medulloblastomas, low-grade astrocytomas, ependymomas, craniopharyngiomas, and brainstem gliomas.
• Treatments that are fairly well-tolerated by the adult brain (such as radiation therapy) are not suitable treatments for children because they may prevent normal development of a child's brain, especially in children younger than age five.

The pediatric surgeons at Semmes Murphey are recognized as the leading experts in treating and operating on brain tumors in children. Through their years of providing surgery services for St Jude Children’s Research Hospital, LeBonheur Children’s Hospital, and many others, the Semmes Murphey surgical team has become one of the most experienced in the world. Semmes Murphey team members have participated in many ground-breaking treatment protocols to help improve the survival rate in children with this disease.

Symptoms vary depending on the location of the brain tumor, but the following may accompany different types of brain tumors:

• Headaches that may be more severe in the morning
• Seizures or convulsions
• Difficulty thinking, speaking or articulating
• Personality changes
• Weakness or paralysis in one part or one side of the body
• Loss of balance or dizziness
• Vision changes
• Hearing changes
• Facial numbness or tingling
• Nausea or vomiting
• Confusion and disorientation

A variety of sophisticated imaging techniques are used in diagnosing and pinpointing brain tumors during surgery.

• Diagnostic tools include computed tomography (CT or CAT scan) and magnetic resonance imaging (MRI).
• Intraoperative MRI is also used during surgery to guide tissue biopsies and tumor removal.
• Magnetic resonance spectroscopy (MRS) is used to examine the tumor's chemical profile and determine the nature of the lesions seen on the MRI.
• Positron emission tomography (PET scan) can help detect recurring brain tumors.

Sometimes the only way to make a definitive diagnosis of a brain tumor is through a biopsy. The neurosurgeon performs the biopsy and the pathologist makes the final diagnosis, determining whether the tumor appears benign or malignant, and grades it accordingly.

Decisions as to what treatment to use are made on a case-by-case basis and depend on a number of factors. But brain tumors (whether primary or metastatic, benign or malignant) are usually treated with surgery, radiation, and chemotherapy — alone or in various combinations.

There are risks and side effects associated with each type of therapy. It’s important for patients to talk openly with their surgeon, family and other trusted sources of information and support.

It is generally accepted that complete, or nearly complete, surgical removal of a brain tumor is beneficial for a patient.

To do this, neurosurgeons traditionally open the skull through a craniotomy to help ensure they can access the tumor and remove as much of it as possible. The neurosurgeon's goal is to remove as much tumor as possible, without injuring brain tissue important to the patient's neurological function (such as the ability to speak, walk, etc.).

Another operation commonly performed is the astereotactic biopsy. This smaller operation sometimes is done before a craniotomy to obtain a small tissue sample which helps doctors make an accurate diagnosis.

The neurosurgeons at Semmes Murphy are some of the best and most experienced in the world. They also have the most advanced and comprehensive computerized devices to assist them.

• The surgical navigation system provides neurosurgeons specific guidance, location, and orientation for tumors. This information reduces the risks and improves the extent of tumor removal. In many cases, surgical navigation systems have allowed previously inoperable tumors to be excised with acceptable risks. Some of these systems can also be used for biopsies.

One limitation of these systems is that they utilize a scan (CT or MRI) obtained prior to surgery to guide the neurosurgeon. Thus, they cannot account for movements of the brain that may occur during surgery. Investigators are developing techniques using ultrasound and performing surgery in MRI scanners to help update the navigation system data during surgery.

• Intraoperative Language Mapping is considered a critically important technique for patients with tumors affecting language function, such as large, dominant-hemisphere gliomas. During this procedure, the patient is conscious, so their language function can be mapped during the operation to show the doctor which portions of the tumor are safe to remove.

• Ventriculoperitoneal Shunting may be required for some brain tumor patients whose spinal fluid is creating pressure. Everyone has cerebrospinal fluid (CSF) within the brain and spine that is slowly circulating all the time. If this flow becomes blocked, the sacs that contain the fluid (the ventricles) can become enlarged, creating increased pressure within the head, resulting in a condition called hydrocephalus. If left untreated, hydrocephalus can cause brain damage and even death. The neurosurgeon may decide to use a shunt to divert the spinal fluid away from the brain and, therefore, reduce the pressure. The body cavity in which the CSF is diverted usually is the peritoneal cavity (the area surrounding the abdominal organs). This shunt is usually permanent. If it becomes blocked, the similar symptoms to the original condition of hydrocephalus (headaches, vomiting, visual problems, and/or confusion or lethargy, among others) may occur.

This information was provided by the specialists at Semmes Murphey Clinic. Readers are encouraged to research trustworthy organizations for information. Please talk with your physician for websites and sources that will enhance your knowledge and understanding of this issue and its treatment.