Gliomas arise from glial cells which make up the supporting tissues of the brain. According to the American Cancer Society, high grade malignant gliomas are the most common types of brain and spinal cord malignant tumors.
Treatment options for high grade gliomas depend on the type and location of the glioma and the extent of its spread.
Surgery
According to the American Cancer Society, this is the first step in treatment of most brain tumors, including high grade gliomas. A craniotomy--opening of the skull--is the surgery done, through which an attempt is made at removing as much of the glioma as possible, without affecting normal brain function. Surgery, however, does not achieve complete cure in high grade gliomas, says the ACS. A dissolvable chemotherapy wafer can also be implanted in the area of the glioma during a craniotomy.
According to the American Society of Clinical Oncologists, the surgery provides tissue for further testing to determine the best approach in further treatment. Surgery also relieves the pressure of the mass on other surrounding brain tissue and reduces the amount of cancer that subsequent treatments have to clear.
The ASCO also describes the placement of a shunt to relieve the build up of fluid in cases with blocked outflow of cerebrospinal fluid in the brain due to cancerous growths from high grade gliomas, especially ependymomas.
Radiation Therapy
The best treatment for those high grade gliomas that cannot be treated by surgery is radiation therapy, with or without chemotherapy, says the American Cancer Society. Radiation therapy, with or without chemotherapy, can also follow surgery in the treatment of gliomas.
The types of radiation therapy mentioned by the ACS in the treatment of gliomas are external beam radiation therapy; three-dimensional conformal radiation therapy, or 3D-CRT; intensity modulated radiation therapy, or IMRT; conformal proton beam radiation therapy; and stereotactic radiosurgery or radiotherapy. Brachytherapy, internal radiation therapy using implants into the tumor area, is also used in high grade gliomas and may be used alongside external forms.
Chemotherapy
The use of drugs that destroy cancer cells, chemotherapy is also an important part of the treatment of high grade gliomas. This form of treatment can be delivered systemically, by oral pills and intravenous injections. It can also be delivered regionally by injections into the cerebrospinal fluid, the fluid that washes over the brain and spinal cord. Regional chemotherapy is typically through a spinal injection. Local chemotherapy, where a chemotherapy wafer is placed directly inside the area of the tumor during a craniotomy has already been mentioned.
Temozolomide is the preferred drug for initial treatment in high grade gliomas, according to the American Cancer Soceity. Other drugs used include carmustine, cisplastin, vincristine, procarbazine and lomustine. Combinations of the drugs can be given for better results, like the common PCV regimen of procarbazine, lomustine and vincristine.
Targeted Therapy
The use of drugs designed to target specific cancer structures and functions is called targeted therapy. Some cases respond to the addition of bevacizumab, a drug designed to block the formation of new blood vessels which the cancers require to grow and spread, to standard chemotherapy.
Supportive Treatment
Steroids may be given to control swelling in the brain and may be prescribed before and after surgery in the treatment of high grade gliomas, according to the American Society of Clinical Oncologists.
Anticonvulsants to prevent or control the frequency of convulsions are also used in the treatment of high grade gliomas. Antidepressants may also be used to treat occult depression in these cases.
References
- American Cancer Society: What Are Brain and Spinal Cord Tumors?
- American Society of Clinical Oncologists: Brain Tumor Treatment
- American Cancer Society: Treatment of Specific Types of Brain and Spinal Cord Tumors
- American Cancer Society: Brain / CNS Tumors in Adults: Surgery
- American Cancer Society: Brain / CNS Tumors in Adults: Radiation Therapy
