Author/Authors :
Hashemian، Abdolreza نويسنده Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, 2 Medical Physics Research Center, Mashhad University of Medical Sciences , , Bahreyni Toossi، Mohammad Taghi نويسنده Department of Medical Physics, Faculty of Medicine, Mashhad University of Medical Sciences, 2 Medical Physics Research Center, Mashhad University of Medical Sciences , , Nasseri، Shahrokh نويسنده Medical Physics Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran ,
Abstract :
Multileaf collimator (MLC) is among the radiation field shaping systems used for conformal radiotherapy and intensity modulation
radiation therapy techniques. The MLC system that has been designed and fabricated in this study includes 52 leaves, 52 stepper
motors, 2 DC motors, 16 programmable logic controllers (PLCs) and one human machine interface (HMI). This system can be mounted on conventional linear accelerators (linac) as an add on accessory. The 52 leaves are mounted on two carriages that are moved independently. The leaves sequence acquired from the image processing of computed tomography images is used to arrange leaves. This sequence is saved in a text file. The leaves are arranged by HMI and labVIEW. Using HMI it is possible to test the operation of PLCs and manually enter the numerical values of the leaves edges. An executable file is developed by labVIEW program, which is graphically user interfaced between the operator and the MLC control system. The projected width of each leaf on the isocenter accelerator (usually at 100 cm from the source) is 10 mm. The positioning accuracy of each leaf is approximately 1.4 mm.
