Information and examples on FLUKA Monte Carlo simulations
- 1 Information and examples on FLUKA Monte Carlo simulations
- 1.1 Introduction to FLUKA
- 1.2 Flair and Flair-Geoeditor
- 1.3 Installation and running
- 1.4 Lectures, presentations and exercises
- 1.5 Examples
- 1.6 Existing FLUKA projects
- 1.6.1 Simulations of a Therapeutic Proton Beam with FLUKA Monte Carlo Code and Varian Eclipse Proton Planning Software - Master thesis work by Kine Johnsen
- 1.6.2 Dosimetric Consequences of Dropping the Momentum Analysis System in a Compact Proton Therapy System - Project thesis by Eivind Rørvik
- 1.6.3 Biasing exercise from Workshop
Introduction to FLUKA
FLUKA is a general purpose Monte Carlo code and is used for a number of applications in experimental physics, dosimetry, detector design, medical physics and radio-biology.
Flair and Flair-Geoeditor
Flair is the Graphical user interface for FLUKA and is used for preparing the simulation as well as running the simulations, process and plot the data (through Gnuplot). Flair also contain a geometry viewer/editor named flair-geoviewer, which is used for visualization and editing of the simulation geometry.
The Flair-Geoeditor (previously geoviewer)can be used for visualization and edition of the geometry. Several tutorials are available on youtube. See e.g. this tutorial on selection of regions and zones.
Installation and running
In order to install FLUKA you must, as a registered user, download the necessary software from the FLUKA web-page. At the University of Bergen we use Ubuntu and the 64bit Gfortran version of FLUKA, and this is what we recommend for new users at the university. If you wish to use a Windows-pc you can download FLUPIX. FLUPIX is Linux Live CD, with pre-installed FLUKA, flair and all the necessary tools in for performing fluka runs. In the packages.txt you will find a complete list of the packages currently included in the ISO image. To save disk space, FLUPIX is only able to run through the VirtualBox machine (www.virtualbox.org) a free and open source Virtual machine supported by Sun. More information on FLUPIX can be found here.
If you wish to install FLUKA, Flair and Flair-Geoviewer yourself, you can find a detailed installation guide here
Lectures, presentations and exercises
The best way to learn FLUKA is to attend one of the courses held by the FLUKA-team. If this is not an immediate option you can find a large number of lectures and exercises from both basic courses and advanced courses on the FLUKA web-page. Lectures and exercises from one of the beginners courses are available here.
Existing FLUKA projects
Simulations of a Therapeutic Proton Beam with FLUKA Monte Carlo Code and Varian Eclipse Proton Planning Software - Master thesis work by Kine Johnsen
The thesis is available in pdf format here.
Kine looked into the source.f user routine in FLUKA in order to be able to define more complex beams than a simple pencil beam. Some example files for creating Spread-Out-Bragg-Peaks for protons and Fluka input files are available here:
Dosimetric Consequences of Dropping the Momentum Analysis System in a Compact Proton Therapy System - Project thesis by Eivind Rørvik
The high investment cost of proton therapy centers could be lowered by building just one single room systems. When a accelerator serves a single treatment room, the beam line could be minimized to cut the cost further. One of the systems available on the market today is cutting the Momentum Analysis system (MAS, Momentum analyser), and degrading the beam directely in front of the patient. The momentum of the beam is then larger compared to other systems, which further enlarges the distal dose falloff, a common dosimetric parameter used in clinics. A higher distal dose falloff will create a higher dose to organs at risk behind the tumor volume, which enlarges the NTCP, as shown in the figure.
The distal falloff of a single bragg peak plotted as a function of the treatment range, of 5 different setups. The three systems without a momentum analyser have approxmataly constant falloff, independent of the range. Every datapoint consist of a single FLUKA simulation of 500 000 initial particles.
In this thesis a simplified 250 MEV proton beam is degraded through PMMA and dropped into a water phantom. The thickness of PMMA i varied to get different clinical relevant ranges. Other proton beams were dropped directly into the water phantom, with realistic ESS/Synchrotron parameters. The bragg curves of the beams were outputted by a usrbin-card, and the range (90%) and distal dose falloff (80%-20%) were analysed by a matlab script. The plot shows the 5 different beams.
As seen, the systems without a MAS have a constant distal dose falloff for all ranges, compared to the ESS/synchrotron systems, which have a almost propotional ratio between the parameters.
At deep treatment depths (prostate etc.), the clinically differences between the systems nearly neglectable. But for close treatment depths (Breast, spine etc), the should be accounted for. For some conditions, as left sided breast cancer, treatment with such a system MIGHT not be favoured over high presision photon therapy. Multiple doseplans should be made and compared for these potential cancer type, to either confirm or rule out the possible dosimetric consequence of dropping the MAS.
The thesis was written in a project course at NTNU under supervision of Pål Erik Goa, in collaboration with Kristian Smeland Ytre-Hauge.