2022 AAPM 64th Annual Meeting
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Session Title: Multi-Scale Modeling in Imaging and Therapy
Question 1: Which one of the following geometrical models can represent certain curved objects at any scale and with unlimited resolution?
Reference:Almansa J et al., PENGEOM—A general-purpose geometry package for Monte Carlo simulation of radiation transport in material systems defined by quadric surfaces, Computer Physics Communications 199, p. 102-113 (2016)
Choice A:Quadric equations.
Choice B:Voxels.
Choice C:Tetrahedral volume mesh.
Choice D:Triangle mesh surface.
Question 2: The geometrical modeling approach that best handles complex anatomical features and organ deformations is called:
Reference:Xu G, An exponential growth of computational phantom research in radiation protection, imaging, and radiotherapy: a review of the fifty-year history, Physics in Medicine and Biology 59, p. R233 (2014). https://doi.org/10.1088/0031-9155/59/18/R233
Choice A:Constructive solid geometry.
Choice B:Boundary representation.
Choice C:Principal components.
Question 3: Which of the following steps in microscopic Monte Carlo simulations is the most computationally challenging?
Reference:Tsai et al., A new open‐source GPU‐based microscopic Monte Carlo simulation tool for the calculations of DNA damages caused by ionizing radiation‐‐‐Part I: Core algorithm and validation, Medical Physics 47, p. 1958 (2020)
Choice A:Physical stage simulation.
Choice B:Physicochemical stage simulation.
Choice C:Chemical stage simulation.
Choice D:DNA damage complexity calculation.
Question 4: Brachytherapy can be administrated using gamma-emitting radionuclides with low energies, intermediate energies, or high energies. Which of the following statements is correct?
Reference:Famulari G, Pater P, Enger SA. Microdosimetric Evaluation of Current and Alternative Brachytherapy Sources-A Geant4-DNA Simulation Study. Int J Radiat Oncol Biol Phys. 100(1), p. 270-277 (2018). doi:10.1016/j.ijrobp.2017.09.040
Choice A:For the high- and intermediate-energy brachytherapy sources, lineal energy tends to decrease with the depth from the source, because the contribution of scattered photons to dose deposition increases with the distance from the source.
Choice B:For low-energy sources such as 125-I, the lineal energy does not vary with the distance from the source owing to a lack of scattered photons.
Choice C:Experimental studies and calculations using x-ray sources, low-energy brachytherapy sources, and electronic brachytherapy sources have shown that a relative biological effectiveness of unity can be applied to all photon emitting sources.
Question 5: Monte Carlo track structure algorithms offer:
Reference:Bernal MA et al., Track structure modeling in liquid water: A review of the Geant4-DNA very low energy extension of the Geant4 Monte Carlo simulation toolkit, Physica Medica 31, p. 861-874 (2015). https://doi.org/10.1016/j.ejmp.2015.10.087
Choice A:A semi-empirical approach to model cell survival.
Choice B:A stochastic approach to model physical interactions and energy deposits on the nanometer scale.
Choice C:Condensed history simulation approach.
Choice D:Experimental data on DNA damage.
Question 6: DNA strand breaks from radiation can occur from:
Reference:Chatzipapas KP et al., Ionizing Radiation and Complex DNA Damage: Quantifying the Radiobiological Damage Using Monte Carlo Simulations, Cancers 12(4), 799 (2020).
Choice A:The direct interaction of ionizing particles.
Choice B:The interaction of free radical species.
Choice C:Combination of direct and indirect effects.
Choice D:All of the above.
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