Radiation Beam Collimation Used in Radiotherapy: Radiotherapy

The objectives of this study are to investigate and compare the dose distribution defined with divergent cerrobend alloy custom blocks to the distribution obtained with multileaf collimator (MLC) provided by high energy linear accelerator. The study was made for simple block replacement situations. Prior to making the comparison, multileaf collimator performance checks will be made. These checks include the following measurements: leaf Attenuation, leaf transmissions, in-between-leaf leakage properties and measurement of tongue and groove effect. By using of ionization chamber in water phantom, percent depth dose, beam flatness, symmetry, penumbra, leaf transmission and leakage will be measured. By using of radiographic films the transmission, penumbra, and verification of leaf position and leaf motion will be determined . Finally output factor of both multileaf collimator and cerrobend block will be measured same field sizes at the same conditions of dosimetry. The final aim of this study to improve the accuracy of cancer treatment delivery

Dr Ehab HegazyLecturer of physics Faculty of engineering Delta University of science and technology EgyptAcademic degree: PhD