Open AccessA benchmarking method to evaluate the accuracy of a commercial proton monte carlo pencil beam scanning treatment planning system
Author(s) -
Lin Liyong,
Huang Sheng,
Kang Minglei,
Hiltunen Petri,
Vanderstraeten Reynald,
Lindberg Jari,
Siljamaki Sami,
Wareing Todd,
Davis Ian,
Barnett Allen,
McGhee John,
Simone Charles B.,
Solberg Timothy D.,
McDonough James E.,
Ainsley Christopher
Publication year - 2017
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/acm2.12043
Subject(s) - imaging phantom , monte carlo method , proton therapy , scattering , computational physics , beam (structure) , physics , materials science , nuclear medicine , atomic physics , optics , medicine , mathematics , statistics
Acuros PT is a Monte Carlo algorithm in the Eclipse 13.7 treatment planning system, which is designed to provide rapid and accurate dose calculations for proton therapy. Computational run‐time in minimized by simplifying or eliminating less significant physics processes. In this article, the accuracy of Acuros PT was benchmarked against both measurement and an independent MC calculation, TOPAS . Such a method can be applied to any new MC calculation for the detection of potential inaccuracies. To validate multiple Coulomb scattering ( MCS ) which affects primary beam broadening, single spot profiles in a Solidwater ® phantom were compared for beams of five selected proton energies between Acuros PT , measurement and TOPAS . The spot Gaussian sigma in Acuros PT was found to increase faster with depth than both measurement and TOPAS , suggesting that the MCS algorithm in Acuros PT overestimates the scattering effect. To validate Acuros PT modeling of the halo component beyond primary beam broadening, field size factors ( FSF ) were compared for multi‐spot profiles measured in a water phantom. The FSF for small field sizes were found to disagree with measurement, with the disagreement increasing with depth. Conversely, TOPAS simulations of the same FSF consistently agreed with measurement to within 1.5%. The disagreement in absolute dose between Acuros PT and measurement was smaller than 2% at the mid‐range depth of multi‐energy beams. While Acuros PT calculates acceptable dose distributions for typical clinical beams, users are cautioned of potentially larger errors at distal depths due to overestimated MCS and halo implementation.