Image-Guided Radiation Therapy (IGRT)

Image-Guided Radiation Therapy (IGRT) is the clinical practice of performing repeated imaging scans (such as cone-beam CTs or X-rays) immediately before or during the delivery of radiotherapy. It is the absolute gold standard for verifying correct patient alignment and tumor targeting.

Why IGRT is Necessary

Internal organs move constantly. The bladder fills and empties, lungs expand and contract, and digestive tract gases shift. Over a 5-week treatment course, a tumor's position can vary from day to day, and the patient's outer setup alignment may not perfectly match their internal anatomy. IGRT solves this by taking a quick low-dose scan while the patient is on the treatment couch, comparing it to the planning scan, and making automatic sub-millimeter table adjustments before the beam turns on.