مقايسه سرعت رايانه هاي موجود در محاسبه دوز عمقي دستگاه پرتو درماني كبالت 60 با روش مونت كارلو با استفاده از كد MCNP4B و MCNP4A

COMPARISON OF DIFFERENT COMPUTER SPEEDS IN CALCULATING OF CO60 DEPTH DOSES BY MCNP4A AND MCNP4B MONTE CARLO CODES

BACKGROUND AND OBJECTIVE: MCNP is a general-purpose Monte Carlo code that is used for simulating of neutrons, photons and electrons transport in different media. Recently this code has been used for radiotherapy dosimetry and treatment planning. In recent investigations, the reasonable run-time was not acquired for clinical use of Monte Carlo method. In this research, the speeds of the computers available in Iran were compared in running a percent depth dose calculation (PDD) for CO60 teletherapy machine. METHODS: Geometry of a typical C060 teletherapy machine and a water phantom were simulated. Both version of MCNP code were installed on Pentium 233, 866, 1500 MHz, 700 MHz Duran and Athelon 1333 MHz personal computers. Percent depth dose of C06° gamma rays in water phantom for 10 x 10 cm was calculated by each computer. FINDINGS: The time required to compute the PDD by F6 tally was 60 times greater than the F8 tally. In all the cases, the 4A version was approximately %5 faster than 413 version. This suggests that in radiotherapy application like our test problem there is not considerable computing time difference between 4A and 4B version. CONCLUSION: The results recommend the use of F6 tally in radiotherapy application by C060 gamma rays where the point of interest are not situated in electronic disequilibrium regions and when the time of calculation is important.