Brain tumor Radiation therapy

In case of a malignant brain tumor, radiation therapy is needed to control the tumor and possibly acheive long-term remission. There are some possible side effects of radiation therapy; these include the possibility of strokes and Dementia. The severity as well as the chance that they happen, worsen with higher doses of therapy. The radiation therapy is usually very well tolerated.

Stereotactic Radiosurgery: Stereotactic radiosurgery is a special form of radiation therapy - it is not surgery. Stereotactic radiosurgery allows precisely focused, high dose X-ray beams to be delivered to a small, localized area of the brain. It is used to treat small brain and spinal cord tumors (both benign and malignant); blood vessel abnormalities in the brain; defined areas of cancer; certain small tumors in the lungs and liver; and neurologic problems such as movement disorders.

Conventional external beam radiation therapy – the most common form of radiation therapy – delivers full dose radiation to the tumor and some of the surrounding brain tissue. For several reasons, the target area for conventional radiation deliberately includes a border (called a “margin”) of normal brain around the tumor. These reasons include uneven tumor borders, the risk of invisible spread of the tumor into the surrounding tissue, a larger tumor size, or the presence of multiple tumors. This larger zone of full-dose radiation includes the borders of the tumor where microscopic tumor cells may be located. Since normal brain tissue is included in the full-dose region, conventional radiation is broken down into small daily doses so the normal brain tissue can tolerate it. As a result, reaching the desired dose of radiation takes several weeks of daily treatment. Radiosurgery focuses radiation beams more closely to the tumor than conventional external beam radiation. This is possible through the use of highly sophisticated computer-assisted equipment. A head frame or facemask used for this treatment allows very precise set up, localization and treatment of the tumor. Using advanced computer planning, radiosurgery minimizes the amount of radiation received by normal brain tissue and focuses radiation in the area to be treated. Since conventional radiation therapy covers more normal tissue, it can often be given only once. Radiosurgery, however, may be considered for re-irradiation due to its precision and the possibility of avoiding previously treated areas