Thursday, February 23, 2012

Astrocytoma Brain Tumors

What is an Astrocytoma brain  tumor?  Astrocytoma tumors are a form of glioma with star-shaped cells. Glioma is is a type of tumor that starts in the brain or spine. It is called a glioma because it arises from glial cells. The most common site of gliomas is the brain.

Astrocytoma tumors often grow very slowly or not at all for long periods of time. Therefore, close observation rather than treatment is possible in some cases (especially ones associated with neurofibromatosis ). They may occur in many parts of the brain, but most commonly in the cerebrum. They occur less commonly in the spinal cord. People of all ages can develop astrocytomas, but they are more prevalent in adults, particularly middle-aged men. Astrocytomas in the base of the brain are more prevalent in children or younger people and account for the majority of children’s brain tumors. In children, most of these tumors are considered low-grade, while in adults most are high-grade.
General symptoms of an astrocytoma tumor are a result of growing pressure inside the skull. These symptoms include headache, vomiting and mental status changes. Other symptoms, such as drowsiness, lethargy, obtuseness, personality changes, disordered conduct and impaired mental faculties show up early in about one out of every four patients with malignant brain tumors.
In young children, the growing pressure of an astrocytoma tumor inside the skull may enlarge the head. Changes (such as swelling) may be observed in the back of the eye, where the blind spot is. Usually there are no changes in temperature, blood pressure, pulse or respiratory rates except just before death. Seizures are more common with meningiomas, slow-growing astrocytomas and oligodendrogliomas than with malignant gliomas.
Symptoms of an astrocytoma tumor vary depending on what part of the brain (or which glands or nerves) are affected by the tumor. Sometimes the nature of the seizures can help determine the location of the brain tumor.
Astrocytomas are generally classified (graded) into one of three types: Low grade astrocytomas, anaplastic astrocytomas and glioblastomas. Low grade astrocytomas account for 10 percent of astrocytomas. These tumors are typically slow growing and may not require specific treatment at the time of diagnosis. Many patients with low grade astrocytomas live for prolonged periods of time after their diagnosis. However, these tumors often advance into the higher grades and more rapidly growing forms of brain gliomas. Anaplastic astrocytomas and glioblastomas are the most aggressive and, unfortunately, the most common astrocytomas. Glioblastomas are fast growing astrocytomas that contain areas of dead tumor cells. In adults, glioblastoma occurs most often in the cerebrum, especially in the frontal and temporal lobes of the brain.


A neurologic evaluation should be conducted if a patient has slowly increasing signs of mental dysfunction, new seizures, persistent headaches or evidence of pressure inside the skull, such as vomiting or swelling or protrusion of the blind spot at the back of the eye.
A neurologist (a doctor who has received special additional training in the diagnosis and treatment of disorders of the brain, spinal cord and nerves)performs a complete examination, which may include a magnetic resonance imaging (MRI) scan, a computed.

Treatment Options
Treatment options include surgery, radiation, radiosurgery, and chemotherapy. The main goal of surgery is to remove as much of the tumor as possible without injuring brain tissue needed for neurological function (such as the ability to speak, walk, motor skills, etc.). However, high-grade tumors often have tentacle-like structures that invade surrounding tissues, making it more difficult to remove the entire tumor. If the tumor cannot be completely removed, surgery can still reduce or control tumor size. In most cases, surgeons open the skull through a craniotomy to best access the tumor site. The goal of radiation therapy is to selectively kill tumor cells while leaving normal brain tissue unharmed. In standard external beam radiation therapy, multiple treatments of standard-dose "fractions" of radiation are applied to the brain. Each treatment induces damage to both healthy and normal tissue. By the time the next treatment is given, most of the normal cells have repaired the damage, but the tumor tissue has not. This process is repeated for a total of 10 to 30 treatments, depending on the type of tumor. This additional treatment provides some patients with improved outcomes and longer survival rates.
Radiosurgery is a treatment method that uses computerized calculations to focus radiation at the site of the tumor while minimizing the radiation dose to the surrounding brain. Radiosurgery may be an adjunct to other treatments, or it may represent the primary treatment technique for some tumors
Patients undergoing chemotherapy are administered special drugs designed to kill tumor cells. Although chemotherapy may improve overall survival in patients with the most malignant primary brain tumors, it does so in only about 20 percent of patients. Chemotherapy is often used in young children instead of radiation, as radiation may have negative effects on the developing brain. The decision to prescribe this treatment is based on a patient’s overall health, type of tumor, and extent of the cancer. Before considering chemotherapy, you should discuss it with your doctor, as there are many side effects.
Because traditional treatment modalities are unlikely to result in a prolonged remission of malignant astrocytomas, researchers are presently investigating a number of promising new treatments including gene therapy, highly focused radiation therapy, immunotherapy and novel chemotherapies. A number of new treatments are being made available on an investigational basis at centers specializing in brain tumor therapies.

                                           Astrocytoma Explained by Dr. Mark Atlas

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