Intensity Modulated Radiation Therapy (IMRT)

Description of the PEACOCK® IMRT Animation

What are we seeing?
The animation depicts a patient lying on a treatment couch with PEACOCK® IMRT treatments being delivered over a continuous 270° arc. The black object represents the MIMiC® attached to a linear accelerator. The various shades of yellow in the beams reflect changes in intensity as the MIMiC rotates around the patient.

In this animation, the primary target is outlined in red and a separate secondary target, with a lower dose prescription, is outlined in purple. For this actual patient, two distinct prescriptions were used - one for each target. 70 Gy was delivered for the primary target and 60 Gy for the secondary target delivered in 28 fractions. The secondary target is located between the primary target and the right parotid gland. The structures to be spared are the spinal cord, the parotid glands and the mandible.

As the animation progresses, changes in color-wash intensity reflect actual dose accrual. The dark red reflects the highest amount of dose. Light orange, light yellow and no color represent relative sparing of normal tissue.

Note
Critical structures like the spinal cord and the parotids, do not typically have beams through them. As CORVUS® generates the plan, the structures' dose tolerances are taken into consideration and a sequence of beam intensities is selected when optimal target coverage is achieved.