Particle Tracking Data: Bergen DTC Prototype

Dataset Description: Proton computing tomography is an imaging modality promising improved treatment planning for proton therapy. For this application, the Bergen pCT collaboration is developing a high granularity Digital Tracking Calorimeter (DTC), capable of measuring high multiplicities of particles in parallel [1]. In this dataset, we include various Monte Carlo (MC) simulations (generated using the Gate 9.2 simulation toolkit [2, 3] built upon Geant4 [4,5,6]) with different setups and phantom materials for evaluating and comparing particle reconstruction algorithms on the Bergen DTC.

Files: We provide multiple simulations for different phantom geometries and simulation setups, each generated with a mono-energetic pencil beam (230 MeV, 2 sigma). The supplied files include a spot scanning dataset generated for a pediatric head phantom [7], spot scanning on water phantoms (100, 150 and 200 mm) as well as single beam spots for water phantoms of various thicknesses (0, 100, 150 and 200 mm):

• head_filtered_2k_spot.npz
• water_{100,150,200}_2k_spot.npz
• water_{100,150,200}_10k.npz
• no_phantom_10k.npz

Columns: All above-mentioned simulation files contain MC simulated data of a single simulation run in tabular form, where each row represents a single particle hit inside the detector. Furthermore, each particle hit is parametrized by the following columns:

• posX, posY, posZ: Measured x, y, z position (in millimeter) of the particle hit relative to the simulation origin defined by the center of the phantom.
• edep: Amount of energy (in MeV) deposited by a particle while interacting with the sensitive area of the detector.
• eventID: Each primary is simulated in its own isolated "event" and gets an incremental ID. Everything that happens during the simulation of said primary is grouped under the same eventID. Events are simulated independent of each other. trackIDs are only unique within their respective event.
• trackID: A track describes a single particle throughout its entire lifetime in the simulation. In any given event, the first track (trackID = 1) is always associated with the primary particle. Every subsequently produced secondary particle has an incremental trackID.
• parentID: The parentID specifies the trackID in the current event that caused this track to exist. If the parentID is 0, the particle is a primary, i.e., generated by the particle beam. Otherwise, the row describes a secondary which was generated through interactions of a primary with the traversed matter.
• volumeID[2]: Incremental numerical identifier of layer containing particle hit inside GATE volume 2 defined within the detector geometry. 0 for tracking layers, 1 for calorimeter layers.
• volumeID[3]: Incremental numerical identifier of layer containing particle hit inside GATE volume 3 defined within the detector geometry.  Unique identifiers (starting from zero) for tracking layer (0, 1) and calorimeter layer (0, 1, …, 40).

References

[1] J. Alme, G. G. Barnafoldi, R. Barthel et al., “A High-Granularity Digital Tracking Calorimeter Optimized for Proton CT, ”Frontiers in Physics, vol. 8, no. October, pp. 1–20, 2020.

[2] S. Jan, G. Santin, D. Strul et al., “GATE -Geant4 Application for Tomographic Emission: a simulation toolkit for PET and SPECT,”Phys Med Biol. Phys Med Biol, vol. 49, no. 19, pp. 4543–4561, 2004.

[3] S. Jan, D. Benoit, E. Becheva et al., “GATE V6: A major enhancement of the GATE simulation platform enabling modelling of CT and radiotherapy, ”Physics in Medicine and Biology, vol. 56, no. 4,pp. 881–901, 2011.

[4] S. Agostinelli, J. Allison, K. Amako et al., “GEANT4 - A simulation toolkit, ”Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 506, no. 3, pp. 250–303, 2003.

[5] J. Allison, K. Amako, J. Apostolakis et al., “Geant4 developments and applications, ”IEEE Transactions on Nuclear Science, vol. 53, no. 1, pp. 270–278, 2006.

[6] J. Allison, K. Amako, J. Apostolakis et al., “Recent developments in geant4”, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 835, pp. 186–225, 201

[7] V. Giacometti, S. Guatelli, M. Bazalova-Carter et al., “Development of a high resolution voxelised head phantom for medical physics applications. ”Physica Medica, vol. 33, pp. 182–188, 2017.