The TOPAS toolkit aims to provide an intuitive Monte Carlo framework for medical physicists and researchers in related fields. TOPAS is based on the Geant4 Simulation Toolkit and offers specific extensions for application in Radiation Oncology. The text-based TOPAS parameter control system allows users to create their own Monte Carlo simulations using a large library of components and examples built by the TOPAS developers and its users, including particle sources, geometry components, scorers, outcome models, time features, etc. TOPAS provides immense flexibility to design your own simulation without writing C++ code.
In addition, TOPAS offers an extension mechanism that requires only minimal C++ coding for advanced users who want to add new functionalities. Extension classes have access to all of the features of TOPAS and Geant4. Since version 4.0, TOPAS has been released as OpenTOPAS and is based on Geant4.11.
To discover the Geant4 version used by a specific version of TOPAS, please consult the :ref:`version` section.
Note
A PDF version of the documentation is found by clicking the "Read the Docs" panel in the bottom-right corner of the website.
.. toctree::
:hidden:
:maxdepth: 1
:caption: Getting Started
getting-started/install
getting-started/authors
getting-started/citation
getting-started/users
getting-started/G4_version
.. toctree::
:hidden:
:maxdepth: 1
:caption: Simulation Control
parameters/intro/index
parameters/defaults
parameters/overall/index
parameters/material
parameters/geometry/index
parameters/source/index
parameters/physics/index
parameters/scoring/index
parameters/graphics
parameters/time
parameters/variance/index
parameters/outcome
parameters/GUI
parameters/parameter_optimization
examples-docs/MVLinac/intro
.. toctree::
:hidden:
:maxdepth: 1
:caption: Example Parameter Files
examples-docs/Basic/index
examples-docs/Brachytherapy/index
examples-docs/Graphics/index
examples-docs/MVLinac/index
examples-docs/Nozzle/index
examples-docs/Optical/index
examples-docs/Outcome/index
examples-docs/Patient/index
examples-docs/PhaseSpace/index
examples-docs/Scoring/index
examples-docs/SpecialComponents/index
examples-docs/TimeFeature/index
examples-docs/UCSFETF/index
examples-docs/VarianceReduction/index
.. toctree::
:hidden:
:maxdepth: 1
:caption: How to Extend OpenTOPAS
extension-docs/intro
extension-docs/geometry
extension-docs/source
extension-docs/physics
extension-docs/scoring
extension-docs/outcome
extension-docs/filtering
extension-docs/field
extension-docs/imaging
extension-docs/user_hook
.. toctree::
:hidden:
:maxdepth: 1
:caption: Provided Extensions
extensions/rbe/intro
extensions/imaging/index
extensions/microdosimetry/intro