Image-guided radiation therapy
Image-guided radiation therapy (IGRT) uses X-ray, cone-beam CT scanning, electromagnetic tracking, optical surface tracking, or ultrasound imaging during treatments to locate and focus radiation beams precisely at the tumors. IGRT is used to treat cancerous and noncancerous tumors and is ideal to treat tumors located very close to sensitive structures and organs.
Tumors can move internally in the body because of breathing or other body movements. In order to deliver precise treatment, IGRT sets up the radiation treatment exactly on target. Pictures are taken before, and even during, the time that radiation is being delivered to confirm that the alignment is pin-point perfect.
The physicians compare images taken during a treatment simulation to past and new images taken of the patient’s tumor. Based on this comparison and taking into account any movement of the tumor, the physician can make necessary adjustments to the patient’s position or the radiation beams to precisely target the tumor and avoid healthy tissue.