Dosimetric control of dose distribution calculated in computerized treatment planning system

Abstract

OBJECTIVESThe purpose of this study is providing dosimetric control by comparing dose values calculated in computerized treatment planning system (CTPS) and measured by Linear 2D-Array and ion chambers of various volumes.METHODSFields measured by Farmer, Semiflex and PinPoint ion chambers were created in CTPS. Using Linear 2D-Array, measurements were done in open, isocentric, oblique and wedge filtered fields which created in CTPS. Dose values were compared.RESULTSPinPoint ion chamber measured top dose values whereas Farmer ion chamber measured low values. The most compatible results with CTPS were obtained by Semiflex ion chamber. However, in 2D-Array measurements, concordance was observed with CTPS in central axis, difference reached 20 % in build-up and penumbra regions.CONCLUSIONThe most compatible results with CTPS were obtained by Semiflex ion chamber. Reasons of discordance in 2D-Array measurements were found as; varible dose around build-up region, and not to obtain the exact superpose of profiles' penumbra region.