TY - UNPB

T1 - Finite-element modeling of the alpha particle dose of realistic sources used in Diffusing Alpha-emitters Radiation Therapy

AU - Heger, Guy

AU - Arazi, Lior

PY - 2021/11/6

Y1 - 2021/11/6

N2 - Diffusing Alpha-emitters Radiation Therapy (DaRT) is a new method for
treating solid tumors using alpha particles. Unlike conventional
radiotherapy, where the physical models for dose calculations are known
and routinely used, for DaRT a new framework, called the
Diffusion-Leakage (DL) model, had to be developed. In this work we
provide a detailed description of a finite-element numerical scheme for
solving the time-dependent DL model equations for cylindrical DaRT
sources (``seeds'') of finite diameter and length in two dimensions.
Using a fully-implicit scheme and adaptive time step, this approach
allows to accurately follow temporal transients ranging from seconds to
days. In addition to the full two-dimensional calculation, we further
provide a closed-form approximation and a simple one-dimensional scheme
to solve the equations for infinitely-long cylindrical sources. These
simpler solutions can be used both to validate the two-dimensional code
and to enable efficient parameter scans to study the properties of DaRT
seed lattices. We compare these approximations to the full 2D solution
over the relevant parameter space, providing guidelines on their
usability and limitations.

AB - Diffusing Alpha-emitters Radiation Therapy (DaRT) is a new method for
treating solid tumors using alpha particles. Unlike conventional
radiotherapy, where the physical models for dose calculations are known
and routinely used, for DaRT a new framework, called the
Diffusion-Leakage (DL) model, had to be developed. In this work we
provide a detailed description of a finite-element numerical scheme for
solving the time-dependent DL model equations for cylindrical DaRT
sources (``seeds'') of finite diameter and length in two dimensions.
Using a fully-implicit scheme and adaptive time step, this approach
allows to accurately follow temporal transients ranging from seconds to
days. In addition to the full two-dimensional calculation, we further
provide a closed-form approximation and a simple one-dimensional scheme
to solve the equations for infinitely-long cylindrical sources. These
simpler solutions can be used both to validate the two-dimensional code
and to enable efficient parameter scans to study the properties of DaRT
seed lattices. We compare these approximations to the full 2D solution
over the relevant parameter space, providing guidelines on their
usability and limitations.

KW - Physics - Medical Physics

U2 - 10.48550/arXiv.2111.03939

DO - 10.48550/arXiv.2111.03939

M3 - Preprint

BT - Finite-element modeling of the alpha particle dose of realistic sources used in Diffusing Alpha-emitters Radiation Therapy

ER -