Background: Two protocols of AAPM TG-51 and
IAEA TRS-398 were compared followed by a measurement
and Monte Carlo simulation of beam quality
correction factor, KQ, AAPM TG-51 and IAEA TRS-398
protocols were compared for the absorbed dose to
water for DW, and KQ parameters. Materials and
Methods: Dose measurements by either protocols
were performed with cylindrical and plane parallel
chambers for 6 and 18 MV photons, and 6, 9, 12, 15,
18 MeV electron clinical beams were traced to the
calibration factor of Iranian secondary standard
dosimetry laboratory. MCNP-4C simulation of depth
doses, beam profiles and KQ factors were validated
typically for 18 MV and 12 MeV beams by experimental
measurements. Results: The differences between
simulation and measurements were 0.07% for beam
profile, -2.60% and 1.19% for 12 MeV build up and
linear portion of the depth dose curve, respectively.
The figures of merit for 18 MV were about -4.17%, -
1.62% and 0.38%. The differences of KQ's between
simulation and measurement of 12 MeV, and 18 MV
beams for TG-51 were -0.194% and 0.169%, and for
TRS-398, they were about -0.465% and 0.097%,
respectively. Conclusion: These differences between
the two dosimetry protocols (IAEA TRS-398 & AAPM
TG-51) from the point of absolute dosimetry were not
significant at least when they were used under the
same calibration procedure. The good agreement
between Monte Carlo and measurement may also be
even more important regarding the contribution into
the development of radiotherapy treatment planning
system, based on Monte Carlo procedures. Iran. J.
Radiat. Res., 2012 10(1): 43-51
Mahdavi S, Mahdavi M, Alijanzadeh H, Zabihzadeh M, Mostaar A. A Comparison of dosimetric parameters between IAEA TRS-398, AAPM TG-51 protocols and Monte-Carlo simulation. Int J Radiat Res 2012; 10 (1) :43-51 URL: http://ijrr.com/article-1-882-en.html