External Beam Radiation Therapy

External beam radiation therapy involves a series of daily outpatient treatments to accurately deliver radiation to the area at risk.

• Before beginning treatment, you will be scheduled for a simulation to map out the area being treated. This will involve having X-rays and/or a CT scan. You will also receive tiny tattoo marks on your skin to help the therapists precisely position you for daily treatment.

• Treatment is given once a day, Monday through Friday, for about six weeks.

• Newer technologies like 3-dimensional conformal radiotherapy (3D-CRT) and intensity modulated radiation therapy (IMRT) are being evaluated for use in treating colorectal cancer. Ask your radiation oncologist for more information on these treatments.