Radiation therapy and chemotherapy options vary according to histology and anatomic site of the brain tumor. For glioblastoma, combined modality therapy with resection, radiation, and chemotherapy is standard. Since anaplastic astrocytomas, anaplastic oligodendrogliomas, and anaplastic oligoastrocytomas represent only a small proportion of central nervous system gliomas, phase III randomized trials restricted to them are not generally practical. The natural histories of these tumors are variable, depending on histological and molecular factors; therefore, treatment guidelines are evolving. Therapy involving surgically implanted carmustine-impregnated polymer wafers combined with postoperative external-beam radiation therapy (EBRT) may play a role in the treatment of high-grade gliomas (grade III and IV gliomas) in some patients. Specific treatment options for tumor types are listed below under the tumor types and locations. This section covers general treatment principles.
Since you were recently diagnosed with a brain tumor, ask your doctor these questions at your next visit.
1. What type of brain tumor do I have, and what is its grade?
2. What are the symptoms of brain cancer?
3. What part of my brain is affected by the tumor and what does this region of the brain do?
4. Will it be possible to surgically remove my tumor?
5. Will I need any other treatments such as chemotherapy or radiotherapy after surgery?
6. What are the possible side effects of these therapies?
Dexamethasone, mannitol, and furosemide are used to treat the peritumoral edema associated with brain tumors. Use of anticonvulsants is mandatory for patients with seizures.
Finally, active surveillance is appropriate in some circumstances. With the increasing use of sensitive neuroimaging tools, there has been increased detection of asymptomatic low-grade meningiomas. The majority appear to show minimal growth and can often be safely observed, with therapy deferred until the detection of tumor growth or the development of symptoms.[3,4]
For most types of brain tumors in most locations, an attempt at complete or near-complete surgical removal is generally recommended, if possible, within the constraints of preservation of neurologic function and underlying patient health. This recommendation is based on observational evidence that survival is better in patients who undergo tumor resection than in those who have closed biopsy alone.[5,6] However, the benefit of resection has not been tested in randomized trials.
Selection bias can enter into observational studies despite attempts to adjust for patient differences that guide the decision to operate. Therefore, the actual difference in outcome between radical surgery and biopsy alone may not be as large as noted in the retrospective studies. An exception to the general recommendation for attempted resection is the case of deep-seated tumors such as pontine gliomas, which are diagnosed on clinical evidence and treated without initial surgery approximately 50% of the time. In most cases, however, diagnosis by biopsy is preferred. Stereotactic biopsy can be used for lesions that are difficult to reach and resect.