Intensity Modulated Radiation

IMRT allows the patient to receive a higher dose of radiation while protecting the surrounding normal tissue structures by varying the size, shape, depth and intensity of the radiation beam across the tumor or target. The intensity is varied by the placement of "leaves", which either block or allow the passage of radiation. Typically several beams from multiple directions are delivered.

By combining these non-uniform beams it is possible to deliver dose distributions that more closely match the shape and volume of the tumor.