Image Guided Radiation Therapy (IGRT)

Image Guided Radiation Therapy (IGRT) is the process of imaging during a course of radiation treatment to direct radiation therapy beams to make sure they coincide with the tumor as outlined using the treatment plan. The patient is localized in the treatment room in the same position as simulated and checked using matching planar megavoltage (MV) images against the digital reconstructed radiographs (DRRs) from the treatment planning CT. If location of the target has moved relative to the initial treatment plan, the computer can calculate the position difference and show the therapist how to move the table in order to make sure that the radiation is delivered to the target according to plan. This process is distinct from the use of imaging to delineate targets and organs in the planning process of radiation therapy (simulation). However, there is clearly a connection between the imaging processes because IGRT relies directly on the imaging modalities from planning as the reference coordinates for localizing the patient.

The goal of the IGRT process is to improve the accuracy of the radiation field placement, and to reduce the exposure of healthy tissue during radiation treatments. In years past, larger planning target volume (PTV) margins were used to compensate for localization errors or tumor movement during treatment. This resulted in healthy human tissues receiving unnecessary doses of radiation during treatment. By improving precision and accuracy through IGRT, radiation is decreased to surrounding healthy tissues, allowing for increased radiation to the tumor.

Contact Us

Phone: 717-274-7500
Address: 845 Tuck St.
 Lebanon PA