Question: What is Image-Guided Radiation Therapy (IGRT), and when is it used to treat prostate cancer?
Answer: IGRT or image guided radiation therapy is used in conjunction with external radiation, most often IMRT. IGRT means that you're using some kind of imaging device, typically ultrasound, x-ray pictures or guiding with radiofrequency beacons to make sure that the radiation is going where it's supposed to be going.
IGRT itself has no side effects. It's just a technology used in conjunction with the radiation, but it gives us the ability to deliver very high doses of radiation to the prostate. It makes us sure that we're restricting the dose to the areas around it where we expect then the patient will have fewer side effects and will get better results.