The Reconstruction Toolkit (RTK), an open-source cone-beam CT reconstruction toolkit based on the Insight Toolkit (ITK)

International audiencePurpose: To develop an open-source toolkit for fast cone-beam CT reconstruction based on the Insight Toolkit. Methods: We have started the Reconstruction Toolkit (RTK, http://www.openrtk.org), an open-source toolkit for cone-beam CT reconstruction, based on the Insight Toolkit (ITK, http://www.itk.org/) and using GPU code extracted from Plastimatch (http://www.plastimatch.org/). RTK is developed by an open consortium (see affiliations) under the non- contaminating Apache 2.0 license. The quality of the platform is daily checked with regression tests in partnership with Kitware which already supports ITK. Results: Several features are already available: Elekta, Varian and IBA inputs, multi-threaded Feldkamp-David-Kress reconstruction on CPU and GPU, Parker short scan weighting, multi-threaded CPU and GPU forward projectors, etc. Each feature is either accessible through command line tools or C++ classes that can be included in independent software. A MIDAS community (http://midas3.kitware.com) has been opened to provide CatPhan datasets of several vendors (Elekta, Varian and IBA). RTK will be used in the upcoming cone-beam CT scanner developed by IBA for proton therapy rooms. Many features are under development: new input format support, iterative reconstruction, hybrid Monte Carlo / deterministic CBCT simulation, etc. Conclusions: RTK has been built to freely share tomographic reconstruction development between researchers and is open for new contributions