Intensity-modulated radiation therapy (IMRT) is a sophisticated therapy of high-precision radiotherapy that depends on computer-controlled x-ray accelerators to deliver precise radiation doses to a malignant tumor or specific areas within the tumor. IMRT also allows higher radiation doses to be focused to regions within the tumor while minimizing the dose to surrounding normal critical structures. IMRT allows for the radiation dose to conform more precisely to the three-dimensional (3-D) shape of the tumor by modulating—or controlling—the intensity of the radiation beam.