Abstract:-
There are many calculation algorithms used in treatment planning systems (TPSs) for external beam radiotherapy. The algorithm input data required to implement a treatment unit in the TPS which generated by PBC and AAA are the beam reference data needed for the subsequent evaluation of the dose calculation algorithm. Problems associated with conventional measurements, e.g., detector limitations and accelerator stability can be circumvented. The success of the implementations was determined by the ability of the dose calculation algorithms to reproduce the algorithm input data, and in most cases the agreement was within +-2%. The ability of the virtual photon accelerator to generate total dose of both primary and phantom-scattered components were used to study the performance of two dose calculation algorithms in the presence of air medium like lung organ. Studies of the beam model and the handling of patient-specific inserts in the dose calculation algorithm were possible due to the ability to utilized for photons is the possibility of evaluating the accuracy achievable in anthropomorphic phantoms based on patient X-ray computed tomography data. Materials and Methods Varian linear accelerator DMX, TPS Eclipse (version 10.33), Absolute dosimetry and relative dosimetry system (PTW, Freiburg,Germany ) and 2D array were used . Results the Calculation of algorithm AAA is more precise and accurate than the algorithm PBC in heterogeneity medium in comparison with practical measurement Conclusion the extent of the effort required to carry out a validation study of the complexity of that described here precludes its use as a routine component of TPS commissioning. A realistic and justfiable recommendation is that commissioning includes tests aimed at confirming that raw beam data have been entered correctly and that the operation of the system is understood. In summary, the study tell us that the observed deviations between TPS calculated using Eclipse version 10.33 and measured dose in the present of heterogeneous medium are well within the tolerance levels. The study also show that the use of Eclipse (version 10.33) TPS, AAA algorithms is recording significant improvement than the previous TPS versions especially in the present of low density inhomogeneity.