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Astrocytoma
What You Should Know About Astrocytoma Brain Tumor
An astrocytoma is a type of glial tumor
- Glial cells, which are "supportive" cells that help brain cells (neurons) function, are the most common cellular component of the brain.
- The most common type of glial cell is an astrocyte. More than three quarters of all gliomas are astrocytomas. Other types of gliomas include oligodendroglioma and ependymoma.
- Pilocytic astrocytomas, the most benign variant, are rare and found almost exclusively in children.
- On the other end of the spectrum is the glioblastoma-one of the most malignant tumor types found in the body.
- Treatment options depend on such factors as tumor location, size, and grade.
Diagnosing Astrocytoma
- Imaging
- Magnetic resonance imaging (MRI) is the most sensitive and best method of detecting brain tumors.
- Computed tomography (CT) scans can also be used; however, the degree of detail that can be picked up by CT is much less than MRI.
- Sometimes, other advanced imaging techniques can further help doctors in the diagnosis of astrocytomas.
- Biopsy
- Once a mass is suspected by any of the imaging techniques available, the diagnosis needs to be confirmed by obtaining a biopsy of the mass.
- The biopsy will help differentiate tumor from other types of masses, such as infection. The microscopic structure of the tumor will be important in grading the tumor.
- Tumor grading
- Important for prognosis and therapy, the tumor grade is an estimate of how aggressive, or malignant, a tumor will behave. Tumors are graded based on the microscopic examination of the tumor specimen. The specimen is scanned to see if any part demonstrates malignant characteristics.
- For astrocytomas, there are four general grades:
- Grade 1: Pilocytic Astrocytoma
- Grade 2: Low-grade Astrocytoma
- Grade 3: Anaplastic Astrocytoma
- Grade 4: Glioblastoma
Treatment
- Surgery
- Almost always necessary in order to obtain a piece of tumor tissue for grading, surgery also can be used to remove the mass effect and pressure caused by the tumor.
- Because glial tumors, including astrocytomas, typically infiltrate surrounding "normal-appearing" brain tissue, surgery is not performed with the intention of obtaining a cure (except for some pilocytic and rare low-grade astrocytomas).
- Radiation
- Once the diagnosis is confirmed, higher grade astrocytomas usually undergo radiation therapy.
- Radiation can be administered to the whole brain or it can be relatively focused to a region of the brain. At the same time, or following radiation therapy, one or more chemotherapeutic agents can be used.
- The UCLA Neuro-Oncology Program has several clinical trials for which patients can be considered.
Outcome - Astrocytoma
- Several clinical studies demonstrate that the extent of tumor resection correlates with outcome for both low- and high-grade astrocytomas. However, benefit occurs only when more that 98 percent of the tumor visible on MRI was removed.
- Our research indicates that surgeries performed in a standard operative room have a greater probability of leaving behind tumor visible on the post-operative MRI.
- UCLA is one of the few hospitals to have operating rooms equipped with intra-operative MRI scanners. Intra-operative MRI allows our neurosurgeons to determine whether any residual tumor is present prior to closing the wound, enabling more complete resections.
