Brain Tumors: Primary - Surgery

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Delivery of Radiation Beams. Once the preliminary planning stage has been completed, treatment begins. Several advanced machines, such as the gamma knife and adapted linear accelerator (LINAC), are used with stereotaxy to deliver very focused beams of radiation. Actual treatment takes 10 minutes to 1 hour.

• The gamma knife uses gamma rays that are sent from multiple points to converge at a single point on the tumor. Although each gamma-ray beam is very low dosage, when the beams converge, the intensity and destructive power is very high. The gamma knife is used only on very small tumors and so is generally useful as a booster after standard radiation, surgery, chemotherapy, or combinations.
• The linear accelerator (LINAC) produces protons (positively-charged atomic particles) in patterns that are matched to the tumor shape. The patient is positioned on a bed that can be moved to allow flexible positioning. It allows treatment over multiple sessions of small doses (fractionated stereotactic radiotherapy), instead of a single session. This means that larger tumors can be treated.

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Drugs Used With Radiation

Researchers are studying drugs that may be used along with radiation to increase the effectiveness of the treatment.

Radioprotectors. Drugs such as amifosistine (Ethyol) may protect healthy cells during radiation.

Radiosensitizers. Drugs such as fluorouracil (5-FU) and cisplatin (Platinol) may help make cancerous cells more sensitive to radiation.

Side Effects of Radiation

Common Side Effects. Side effects of radiotherapy may vary depending on the tumor type and radiation treatment. Side effects may include hair loss, fatigue, and nausea and vomiting. Skin irritation and sensitivity may develop in the areas being treated. To prevent further irritation, avoid scratching or rubbing, avoid direct sunlight and heating pads, and do not attempt to treat the symptoms yourself. (Ask your doctor or radiation therapist for advice.) Brain swelling (edema) is another common radiotherapy side effect, which can sometimes cause an increase in brain tumor symptoms. Edema can be treated with steroids.

Tissue Injury. Radiation necrosis (total destruction of nearby healthy tissue) occurs in about 25% of patients treated with intensive radiation. Radiation necrosis can cause brain swelling and reduction in mental functions. The condition is treated with steroids. If steroids prove ineffective, surgery may be required to remove the damaged tissue.