Open AccessCalculating dose from a 2.5 MV imaging beam using a commercial treatment planning system
Author(s) -
Ferris William S.,
Culberson Wesley S.,
Anderson Daniel R.,
Labby Zacariah E.
Publication year - 2019
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1002/acm2.12756
Subject(s) - truebeam , beam (structure) , percentage depth dose curve , nuclear medicine , radiation treatment planning , linear particle accelerator , imaging phantom , materials science , physics , ionization chamber , optics , medicine , radiology , radiation therapy , ion , quantum mechanics , ionization
Patient dose from 2.5 MV images on the TrueBeam linear accelerator is not easily quantified, primarily because this beam energy is not normally modeled by commercial treatment planning systems. In this work we present the feasibility of using the Eclipse® treatment planning system to model this beam. The Acuros XB and the AAA dose calculation algorithms were tested. Profiles, PDDs, and output factors were measured for the 2.5 MV unflattened imaging beam and used for beam modeling. The algorithms were subsequently verified using MPPG 5.a guidelines. Calculated doses with both algorithms agreed with the measurement data to within the following criteria recommended for conventional therapeutic MV beams: 2% local dose‐difference in the high‐dose region, 3% global difference in the low‐dose region, 3 mm distance to agreement in the penumbra, and a gamma pass rate of >95% for 3%/3 mm criteria. Acuros was able to accurately calculate dose through cork and bone‐equivalent heterogeneities. AAA was able to accurately calculate dose through the bone‐equivalent heterogeneity but did not pass within the recommended criteria for the cork heterogeneity. For the 2.5 MV imaging beam, both the AAA and Acuros algorithms provide calculated doses that agree with measured results well within the 20% criteria for imaging beams recommended by AAPM TG‐180.