Definition of image-guided radiation therapy (image-guided radiation therapy (igrt))
Image-guided radiation therapy (IGRT) uses a variety of 2-D, 3-D and 4-D imaging techniques throughout the course of radiation therapy to accurately identify, pinpoint and monitor your tumor for changes. IGRT increases the probability of tumor control and typically results in shorter radiation therapy schedules.
Before treatment, your doctor will use some combination of computerized tomography (CT) scan, magnetic resonance imaging (MRI) and positron emission tomography (PET) scan to define the size, shape and location of your tumor and any nearby critical organs at risk. The types of imaging techniques chosen depend on your disease. Your doctor uses this imaging information to develop your radiation treatment plan and to maximize the dose to the tumor while avoiding surrounding healthy tissue.
Image-guided radiation therapy (IGRT) is ideal for tumors that are very close to sensitive structures and organs or prone to movement or change of shape. During treatment, you’ll typically be immobilized using a body mold or a mask. Markers may be placed on your skin or on the mold or mask for initial treatment positioning and in or near the tumor for added precision.
The care team follows the philosophy of imaging wisely and safely to keep radiation exposure as low as clinically necessary.
IGRT advantages include:
- Accurate radiation delivery
- Improved definition, localization and monitoring of tumor position, size and shape before and during treatment
- The possibility of higher, targeted radiation dosage to improve tumor control
- Decreased radiation exposure to normal tissue surrounding the tumor