Introduction
Brachytherapy is a widely used medical device for cancer treatment (What's brachytherapy).
The software is used by medical physicists to define the treatment planning in order to deliver a therapeutic dose to tumors, preserving the surrounding healty tissues (Role of softwares in brachytherapy) .
A software emploied to define the patient treatment planning must be rigourous and reliable for the cause of the delicate clinical use; the requirements for such a software are listed below.
The brachytherapic dosimetric
software must:
The features of commercial softwares available, used commonly in the clinical practice, are showed in What kind of software is available in hospitals at present.
Brachytherapy example development
The brachytherapy advanced example follows
the Unified Software Development Process; the rigorous software process adopted
contributes to the quality of the product.
The requested functionalities
are listed in the User Requirements.
The design is shown in Brachytherapy
example design.
Validation tests have been
performed ( Tests ).
Features of the brachytherapy example
The brachytherapy example is generalised for all the brachytherapic thecniques.
1.General features shared by the different brachytherapic techniques.
The application satisfies general
functionalities which are shared by the different brachytherapic techniques:
2.Particular
aspects of each brachytherapic source
The application satisfies also
particular
aspects of each brachytherapic device which consist in different source
composition.
The source is defined in the
following terms:
The feature of generalisation + specific aspect of the sources is obtained thanks to the use of the design pattern Abstract Factory.in the geometry structure; in the materials composition; in the energy spectrum of the gamma delivered by the source.
Thanks to the use of this design
pattern, the source definition is completely trasparent: the user communicates
with the abstract object BrachyVFactory, indipendently from the concrete
sorce definition.
The defined sources are:
The user can define other brachytherapic sources without changing the example implementation.the interstitial source Bebig Isoseed I-125; the endocavitary source MicroSelectron HDR Ir-192; Leipzig Applicator.
3.Physics
The Geant4 Low Energy processes
are activated for electrons and gamma.
The Standard Processes
are activated for positrons.
4.Detector
The phantom (sensitive detector)
is devided in voxels (dimension=1mm);
the energy deposit of a voxel
is associated with the center of the voxel itself.
5.Analysis
The results are stored
in the file brachytherapy.hbk.
The AIDA 3.0 toolkit
is used for the analysis.
How to run the application
Results of the simulation
Example of results for all
the brachytherapic techniques are shown in Results
;
the information stored in
the ntuple has been elaborated with analysis devices to obtain the histograms
shown and the isodose curves.
Future
The next project involving the brachytherapy advanced example is the parallelisation of the system and the access to distributed calculation resources.
As explained in What kind of software is available in hospitals at present, MonteCarlo simulations have never been used in the clinical practice because they are slow in terms of computational time, even if the dose calculation is more accurate.
A solution to this problem is given by the parallelisation of the application and the access to distributed resources: in such a way institutes can share CPU and run the simulation in a parallelised way, even if their single CPU resources are poor.
Collaborations