Radiotherapy
Radiotherapy plays a central role in the treatment of most brain tumors, whether benign or malignant.
Radiotherapy after Surgery. Even when it appears that the entire tumor has been surgically removed, microscopic cancer cells often remain in the surrounding brain tissue. Radiation targets the residual tumor with the goal of reducing its size or stopping its progression. If the entire tumor cannot be removed safely, postoperative radiotherapy is often recommended. Even some benign gliomas may require radiation, since they may be life-threatening if their growth is not controlled.
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Radiotherapy When Surgery Is not Appropriate. Radiotherapy may be used instead of surgery for inaccessible tumors or for tumors that have properties that are particularly responsive to radiotherapy.
Radiotherapy and Chemotherapy (Radiochemotherapy). Combining chemotherapy with radiotherapy is beneficial in some patients with high-grade tumors.
Specific Radiation Treatments
Various radiation treatments are now available.
Conventional radiotherapy uses external beams aimed directly at the tumor and is usually recommended for large or infiltrating tumors. It begins about a week after surgery and continues five days per week for six weeks. It should be noted that older adults have a more limited response to external-beam radiation therapy than younger people.
For tumors that are highly localized, the radiation therapist has a choice of other radiation treatments:
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Brachytherapy (also called interstitial radiation) uses radioactive "seeds" implanted directly in the tumor site. It is used as a booster to external beam radiation for patients with malignant astrocytoma. Brachytherapy appears to prolong survival in some aggressive gliomas. It may also be a safe and effective treatment for some children.
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Conformal three-dimensional radiation uses high-dose radiation beams shaped to match the shape of the glioma. This technique is highly targeted and, in certain cases, may even be used with some success for patients who have had previous radiotherapy.
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Hyperfractionated radiation uses many small radiation doses to deliver a high total dosage of radiation.
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A balloon catheter (GliaSite) that delivers radiation to the tumor cavity after surgery is showing promise.
Stereotactic Radiosurgery
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