Examples 4: Dosimetry

In dosimetry example, a cylinder is simulated computing absorbed dose inside it. Different results such as dose, energy deposited… can be plotted. An external source, using GGEMS X-ray source is simulated generating 2e8 particles.

$ python dosimetry_photon.py [-h] [-d DEVICE] [-b BALANCE] [-n N_PARTICLES] [-s SEED] [-v VERBOSE]
-h/--help           Printing help into the screen
-d/--device         OpenCL device (all, cpu, gpu, gpu_nvidia, gpu_intel, gpu_amd, "X;Y;Z"...)
                    using all gpu: -d gpu
                    using device index 0 and 2: -d "0;2"
-b/--balance        Balance computation for device if many devices are selected "X;Y;Z"
                    60% computation on device 0 and 40% computatio on device 2: -b "0.6;0.4"
-n/--nparticles     Number of particles (default: 1000000)
-s/--seed           Seed of pseudo generator number (default: 777)
-v/--verbose        Setting level of verbosity

First, the cylinder phantom is loaded:

phantom = GGEMSVoxelizedPhantom('phantom')
phantom.set_phantom('data/phantom.mhd', 'data/range_phantom.txt')
phantom.set_rotation(0.0, 0.0, 0.0, 'deg')
phantom.set_position(0.0, 0.0, 0.0, 'mm')

Then dosimetry object is associated to the previous phantom, storing all data during particle tracking:

dosimetry = GGEMSDosimetryCalculator('phantom')
dosimetry.set_output('data/dosimetry')
dosimetry.set_dosel_size(0.5, 0.5, 0.5, 'mm')
dosimetry.water_reference(False)
dosimetry.minimum_density(0.1, 'g/cm3')
dosimetry.uncertainty(True)
dosimetry.photon_tracking(True)
dosimetry.edep(True)
dosimetry.hit(True)
dosimetry.edep_squared(True)

And finally an external source using GGEMSXRaySource is created:

point_source = GGEMSXRaySource('point_source')
point_source.set_source_particle_type('gamma')
point_source.set_number_of_particles(200000000)
point_source.set_position(-595.0, 0.0, 0.0, 'mm')
point_source.set_rotation(0.0, 0.0, 0.0, 'deg')
point_source.set_beam_aperture(5.0, 'deg')
point_source.set_focal_spot_size(0.0, 0.0, 0.0, 'mm')
point_source.set_polyenergy('data/spectrum_120kVp_2mmAl.dat')

Dose absorbed by cylinder phantom

Uncertainty dose computation

Photon tracking in phantom

Performance:

Device	Computation Time [s]
GeForce GTX 1050 Ti	253
GeForce GTX 980 Ti	65
Quadro P400	1228
Xeon X-2245 8 cores / 16 threads	570