الفهرس 
General IntroductionOnly 14 pages are availabe for public view
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Abstract
In our study a comparison between different dosimetry protocols had been made. The photon beam of energies 6 and 10 MV produced by a medical linear accelerator Philips SLi15 was used as a radiation source. The radiation dose was measured using water proof ionization chambers as radiation detectors in connection with therapy dosimeters. The tissue phantom ratio (TPR20,10) value and the percentage depth dose (PDD) curves of the two photon energies had been measured. The deviation factor (1) between the TPS calculated and measured PDD values is accepted and located within tolerance criteria. In the present work, many testes had been made to perform the quality assurance of the treatment planning systems (TPS).The output factor values (Sc,p) of different open square field sizes for the two photon beam energies had been measured. The deviation factor (1) of the difference between the TPS calculated and measured Sc,p for different field sizes. Comparisons between the TPS calculated and measured profiles for different open square field sizes for both photon beam energies had been made. The relative error (1) between the TPS calculations and measurements of the whole tested field sizes profiles for both photon beam energies are in coincidence in the regions of the low gradient dose. At the off axis ratio (OAR) and at outside field sizes positions the deviation (2) for both energies are within tolerance criteria. The error of the radiological width (RW)50 for both photon beam energies is out of tolerance criteria. The penumbra error values between TPS calculation and measurement of the tested open square field sizes are within tolerance criteria. The deviation between the TPS calculations and measurements of the open rectangular, oblique and the isocentric open square field sizes (1) are within tolerance criteria for the used photon energies. The values of the absolute errors (WOF) between the calculated and measured wedge output factors (WOF) of the tested wedge field sizes are within tolerance criteria. The deviations between TPS calculations and measurements of PDD, OAR and outside dose values of the used wedged field sizes show an excellent agreement for both photon beam energies 6 and 10MV. Finally the confidence limit () values for all mentioned testes had been calculated and give an excellent evaluation method for the TPS performance. In most cases, (i) for energy 10 MV are less than that for 6MV.