Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Monte-Carlo-based and GPU-accelerated 4D-dose calculator for a
  pencil-beam scanning proton therapy system   Purpose: The presence of respiratory motion during radiation treatment leads
to degradation of the expected dose distribution, both for target coverage and
healthy-tissue sparing, particularly for techniques like pencil-beam scanning
proton therapy which have dynamic delivery systems. While tools exist to
estimate this degraded four-dimensional (4D) dose, they typically have one or
more deficiencies such as ...
  Methods: To quickly compute the 4D-dose, the three main tasks of the
calculator were run on graphics processing units (GPUs). These tasks were:
simulating the delivery of the plan using measured delivery parameters to
distribute the plan amongst 4DCT phases characterizing the patient breathing,
using an in-house Monte Carlo simulation (MC) dose calculator to determine the
dose delivered to each breathing phase, and accumulating the doses from the
various breathing phases onto a single phase for evaluation. The accumulation
was performed by individually transferring the energy and mass of dose-grid
subvoxels, a technique models the transfer of dose in a more physically
realistic manner. The calculator was run ...
  Results: 4D doses were successfully computed for the three test cases with
computation times ranging from 4-6 min on a server with eight NVIDIA Titan X
graphics cards; the most time-consuming component was the MC dose engine. The
subvoxel-based dose-accumulation technique produced stable 4D-dose
distributions at subvoxel scales of 0.5-1.0 mm without impairing the total
computation time. The uncertainties in the beam-delivery simulation ...
  Conclusions: A MC-based and GPU-accelerated 4D-dose calculator was developed
to estimate the effects of respiratory motion on pencil-beam scanning proton
therapy treatments. The calculator can currently be used ...

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The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
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The categories of this paper are: econ