External Beam Radiation Therapy

Radiation therapy treatments are delivered in a series of painless daily sessions. Treatments are usually scheduled daily, Monday through Friday, for five to seven weeks. In some cases, your radiation oncologist may schedule your radiation treatments to be twice a day, with several hours between treatments.

Before beginning treatment, you will be scheduled for a planning session to map out the area your radiation oncologist wishes to treat. This procedure is called a simulation. Simulation involves having X-rays and/or a CT scan. To help you keep still during treatment, your doctor may use a plastic mask over your head and shoulders. You can see and breathe through this form-fitting device which is made to comfortably make sure movement during treatment is minimized. In some cases, other devices may help make sure the radiation to normal parts of the mouth are avoided.

You may also receive tiny marks on your skin, like a permanent tattoo, to help the radiation therapist precisely position you for daily treatment. Sometimes, these marks can be made on the plastic mask so there are no permanent marks on your skin. Ask your radiation oncologist whether you will need any tattoos as part of your simulation.

• Three-dimensional conformal radiotherapy (3-D CRT) combines multiple radiation treatment fields to deliver precise doses of radiation to the affected area.
• Intensity modulated radiation therapy (IMRT) is a specialized form of 3-D CRT that varies the intensity of each radiation beam. IMRT can help lower the chance of having a dry mouth or other side effects.
• Image-guided radiation treatment (IGRT) is a form of 3-D CRT or IMRT that uses imaging to precisely deliver radiation treatment. Your radiation oncologist may take X-rays and/or a CT scan before each treatment. These images are used to precisely align you each day before the treatment starts. This can reduce radiation to your normal tissue.