IMRT QA with 2-dimensional Diode Array of Detectors

This tutorial deals with the intensity-modulated radiation therapy (IMRT) treatment planning quality assurance. Treatment planning system gives an optimal fluence; this fluence distribution is delivered by various multi leave positions called segments for various beams. An evaluation of the verification of the intensity modulated beams is very important in the process of verification of the IMRT plan to the treatment delivery. A 2-dimensional diode array called the MapChek is used for all quality assurance tests. The conventional film or extended range film EDR-2 has been extensively used for the quality assurance of IMRT. The use of film involves many steps where as the use of the 2-d diode array is straight forward and less time consuming. The results obtained from the MapCheck diode array system will be compared with the results from the conventional use of film for quality assurance. Other methods used for IMRT quality assurance are being investigated are electronic portal imaging device (EPID). The objectives are to introduce the MapChech, the set up, calibration of diode array, making the beam fluence measurements, analysis and results about the IMRT QA with MapCheck. The MapCheck system provides accurate information about the dose distribution and is being used at many cancer centers for routine evaluation fluence map evaluation in a direct quantitative approach