Investigation of the effects of cell model and subcellular location of gold nanoparticles on nuclear dose enhancement factors using Monte Carlo simulation

Abstract

NDEF is a new metric that can predict the radiation enhancement of AuNPs for various experimental conditions. Cell model, the subcellular location and size of AuNPs, and the number of AuNPs per cell, as well as the x-ray photon energy all have effects on NDEFs. Larger AuNPs in the nucleus of cluster cells exposed to x-rays of 15 or 40 keV maximize NDEFs.

Heterogeneous multiscale Monte Carlo simulations for gold nanoparticle radiosensitization

“…The demonstrated agreement between our results and those of Koger and Kirkby (Table I, 19 to those previously published using PENELOPE 10 (50 eV electron cutoff) when scoring in microscopic regions. These observations support the use of CH codes and $ 1 keV transport cutoffs in GNPT scenarios in which energy deposition need not be resolved on nm length scales (40 nm range of 1 keV electron in water 39 ) and when self-absorption of sub-1 keV electrons within GNPs 7,10 is relatively unimportant.…”

“…The lattices employed herein for modeling arrays of GNPs are not required as part of the HetMS approach, rather, they may be a useful approach for geometry specification. Lattices have been employed elsewhere for GNPT (discussed above; Refs 3.C).…”

“…[14][15][16][17][18][19] ), but they have not been combined with the homogenized tissue-gold mixtures as done within our HetMS models, nor used within more sophisticated phantoms with multiple GNP lattices to model varying gold concentrations (spherical phantom simulations, section 3.C). Furthermore, the HetMS approach enables considerably more efficient simulations than otherwise possible with discrete modeling of GNPs throughout the entire GNP-containing volume (as done previously [14][15][16][17][18][19] ). We observed efficiency gains of factors of up to 122 within the cylindrical phantom (Table II), with efficiency gains varying with source energy and gold concentration.…”

“…13 Some researchers have discretely modeled GNPs in a macroscopic volume using the simple geometry of a cubic lattice of GNPs embedded in an otherwise homogeneous water or tissue phantom. [14][15][16][17][18] Cai et al 19 used a lattice on a cellular scale, creating a multi-cell configuration containing discretely modeled GNPs spanning (0.24 cm) 3 . Douglass et al 6 modeled single shapes (spheres or spherical shells) to represent aggregates of GNPs within a multi-cell model of total volume (0.04 cm) 3 .…”

New potential for enhancing concomitant chemoradiotherapy with FDA approved concentrations of cisplatin via the photoelectric effect

“…gold NPs, within the tumor and inside the cells may not be homogenous [35–37]. In a Monte Carlo study, Cai et al showed that dose enhancement is highly sensitive to subcellular location of NPs [38]; for the same initial photon energy and the number of NPs per cell, DEF values increase as the location of NPs get closer to the nucleus of the cell. In the calculations in the current work, it was assumed that the CNP are located on the exterior of the cell or tumor sub-volume.…”