Intensity Modulated Radiation Therapy for Head and Neck Cancer
Intensity modulated radiation therapy (IMRT) is a sophisticated radiation therapy delivery method that allows sparing of normal tissues and increased doses of radiation which are delivered to the primary target (tumor). Normal tissues and treatment areas are outlined on each computed tomography (CT) slice. Additional imaging such as computed axial tomography (CAT) scans, magnetic resonance imaging (MRI) and positron emission tomography (PET) scans are often incorporated (fused) with the planning CAT scan. The treatment team along with the physician creates the optimal 3D treatment plan that highly conforms to the target shape with maximal sparing of radiation dose to the adjacent normal body structures. Targets and avoidance structures are evaluated with graphic analysis and dose to normal structures are limited to established safety guidelines. The custom treatment plan uses multiple unique beam angles and each beam has a three dimensional shape due to temporal beam modulation.
All of our IMRT utilizes modern treatment position verification which is termed image guidance radiation (IGRT) on a daily basis. It utilizes two and three-dimensional imaging to ensure correct patient (and consequently tumor) positioning prior to the delivery of the radiation treatment. This helps ensure delivery of the radiation energy to the specific target location for more effective treatment and a minimized risk of damage to surrounding tissue. The imaging procedures are performed simultaneously to provide real time data to the doctor.