If external-beam radiation therapy (the most common kind) is part of your breast cancer treatment, you'll probably have a 20-minute session at a clinic or hospital every weekday for six or seven consecutive weeks. It will go something like this:
To start off, you'll be measured so that your radiation oncologist and his technicians will know exactly where to aim the radiation beam and how to calibrate the correct dosage. "We do a CAT scan of the breast, heart, and lungs just to see where the structures are," says Jay L. Bosworth, MD, a radiation oncologist with the Nassau Radiologic Group in Manhasset, N.Y., and a Fellow of the American College of Radiology. "And we put tiny tattoo dotsthe size of a freckleon the breast" to ensure the radiation is delivered to the right spot every time.