Material and Methods: We performed our measurements on a Saturne 42 lineer accelerator for the most frequently used electron energies of 6, 9 and 15 MeV in our clinic. Measurements were made at SSD 100 cm at the dmax of the electron energies for all of the methods for square and rectangular fields with PTW 1882 0.6 cc ionization chamber and RW-3 solid water phantom. Measurements were compared to the square root and the 1D methods.
Results: The difference between the square root method and direct measurement method in output factor for 6 MeV was between %0.4-3.2; the same difference for measured and 1 D calculated was varied between %0.0-2.4. The variation was between %0.7-3.0 and %0.0-2.4 for 9 MeV and %0.1-2.2; %0.1-0.9 for 15 MeV respectively. Besides; the maximum deviation between the small and large sets of trimmers were found to be % 0.7.
Conclusion: It has been seen that the square root and 1 D method can safely be used in the clinics. However since the output factors obtained from 1D method is closer to the directly measured values. Due to the accuracy of output factors of 1D method to the directly measured values, it has been shown that 1D method has advantages over the square root method.
Keywords : Out-put, square root method, direct measurement method