|   | 
Details
   web
Records
Author (up) AGATA Collaboration (Soderstrom, P.A. et al); Gadea, A.
Title Interaction position resolution simulations and in-beam measurements of the AGATA HPGe detectors Type Journal Article
Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 638 Issue 1 Pages 96-109
Keywords gamma-ray tracking; AGATA; Monte Carlo simulations; HPGe detectors; Fusion-evaporation reactions
Abstract The interaction position resolution of the segmented HPGe detectors of an AGATA triple cluster detector has been studied through Monte Carlo simulations and in an in-beam experiment. A new method based on measuring the energy resolution of Doppler-corrected gamma-ray spectra at two different target to detector distances is described. This gives the two-dimensional position resolution in the plane perpendicular to the direction of the emitted gamma-ray. The gamma-ray tracking was used to determine the full energy of the gamma-rays and the first interaction point, which is needed for the Doppler correction. Five different heavy-ion induced fusion-evaporation reactions and a reference reaction were selected for the simulations. The results of the simulations show that the method works very well and gives a systematic deviation of <1 mm in the FVVHM of the interaction position resolution for the gamma-ray energy range from 60 keV to 5 MeV. The method was tested with real data from an in-beam measurement using a (30)5i beam at 64 MeV on a thin C-12 target. Pulse-shape analysis of the digitized detector waveforms and gamma-ray tracking was performed to determine the position of the first interaction point, which was used for the Doppler corrections. Results of the dependency of the interaction position resolution on the gamma-ray energy and on the energy, axial location and type of the first interaction point, are presented. The FVVHM of the interaction position resolution varies roughly linearly as a function of gamma-ray energy from 8.5 mm at 250 key to 4 mm at 1.5 MeV, and has an approximately constant value of about 4 mm in the gamma-ray energy range from 1.5 to 4 MeV.
Address [Soderstrom, P. -A.; Nyberg, J.; Al-Adili, A.; Atac, A.; Veyssiere, C.] Uppsala Univ, Dept Phys & Astron, SE-75121 Uppsala, Sweden, Email: P-A.Soderstrom@physics.uu.se
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes ISI:000290082600015 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 619
Permanent link to this record
 

 
Author (up) AGATA Collaboration; Domingo-Pardo, C.; Bazzacco, D.; Doornenbal, P.; Farnea, E.; Gadea, A.; Gerl, J.; Wollersheim, H.J.
Title Conceptual design and performance study for the first implementation of AGATA at the in-flight RIB facility of GSI Type Journal Article
Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 694 Issue Pages 297-312
Keywords gamma-Ray spectroscopy; Tracking; Monte Carlo
Abstract The main objective of the Advanced GAmma Tracking Array (AGATA) is the investigation of the structure of exotic nuclei at the new generation of RIB facilities. As part of the preparatory phase for FAIR-NUSTAR, AGATA is going to be installed at the FRS fragmentation facility of the GSI centre for an experimental campaign to be performed in 2012 and 2013. Owing to its gamma-ray tracking capabilities and the envisaged enhancement in resolving power, a series of in-flight gamma-ray spectroscopy experiments are being planned. The present work describes the conceptual design of this first implementation of AGATA at GSI-FRS, and provides information about the expected performance figures. According to the characteristics of each particular experiment, it is foreseen that the target-array distance is adjusted in order to achieve the optimum compromise between detection efficiency and energy resolution, or to cover an specific angular range of the emitted electromagnetic radiation. Thus, a comprehensive Monte Carlo study of the detection sensitivity in terms of photopeak efficiency, resolution and peak-to-total ratio, as a function of the target-array distance is presented. Several configurations have been investigated, and MC-calculations indicate that a remarkable enhancement in resolving power can be achieved when double-cluster AGATA detectors are developed and implemented. Several experimental effects are also investigated. This concerns the impact of passive materials between the target and the array, the angular distribution of the detection efficiency and the influence of target thickness effects and transition lifetimes in the attainable detection sensitivity. A short overview on half-life measurements via lineshape effects utilizing AGATA is also presented. (C) 2012 Elsevier B.V. All rights reserved.
Address [Domingo-Pardo, C.; Gadea, A.] Univ Valencia, CSIC, IFIC, Valencia, Spain, Email: domingo@ific.uv.es
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000311020500041 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1240
Permanent link to this record
 

 
Author (up) AGATA Collaboration; Farnea, E.; Recchia, F.; Bazzacco, D.; Kroll, T.; Podolyak, Z.; Quintana, B.; Gadea, A.
Title Conceptual design and Monte Carlo simulations of the AGATA array Type Journal Article
Year 2010 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 621 Issue 1-3 Pages 331-343
Keywords Monte Carlo code; gamma-ray tracking array
Abstract The aim of the Advanced GAmma Tracking Array (AGATA) project is the construction of an array based on the novel concepts of pulse shape analysis and gamma-ray tracking with highly segmented Ge semiconductor detectors. The conceptual design of AGATA and its performance evaluation under different experimental conditions has required the development of a suitable Monte Carlo code. In this article, the description of the code as well as simulation results relevant for AGATA, are presented.
Address [Farnea, E.; Recchia, F.; Bazzacco, D.] Ist Nazl Fis Nucl, Sez Padova, Padua, Italy, Email: Enrico.Farnea@pd.infn.it
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes ISI:000281109100045 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 390
Permanent link to this record
 

 
Author (up) Aguiar, P.; Rafecas, M.; Ortuño, J.E.; Kontaxakis, G.; Santos, A.; Pavia, J.; Rosetti, M.
Title Geometrical and Monte Carlo projectors in 3D PET reconstruction Type Journal Article
Year 2010 Publication Medical Physics Abbreviated Journal Med. Phys.
Volume 37 Issue 11 Pages 5691-5702
Keywords 3D PET; iterative reconstruction; list-mode reconstruction; ray-tracing techniques; Monte Carlo simulation; system response matrix
Abstract Purpose: In the present work, the authors compare geometrical and Monte Carlo projectors in detail. The geometrical projectors considered were the conventional geometrical Siddon ray-tracer (S-RT) and the orthogonal distance-based ray-tracer (OD-RT), based on computing the orthogonal distance from the center of image voxel to the line-of-response. A comparison of these geometrical projectors was performed using different point spread function (PSF) models. The Monte Carlo-based method under consideration involves an extensive model of the system response matrix based on Monte Carlo simulations and is computed off-line and stored on disk. Methods: Comparisons were performed using simulated and experimental data of the commercial small animal PET scanner rPET. Results: The results demonstrate that the orthogonal distance-based ray-tracer and Siddon ray-tracer using PSF image-space convolutions yield better images in terms of contrast and spatial resolution than those obtained after using the conventional method and the multiray-based S-RT. Furthermore, the Monte Carlo-based method yields slight improvements in terms of contrast and spatial resolution with respect to these geometrical projectors. Conclusions: The orthogonal distance-based ray-tracer and Siddon ray-tracer using PSF image-space convolutions represent satisfactory alternatives to factorizing the system matrix or to the conventional on-the-fly ray-tracing methods for list-mode reconstruction, where an extensive modeling based on Monte Carlo simulations is unfeasible.
Address [Aguiar, Pablo] Univ Santiago de Compostela, Dept Fis Particulas, Complexo Hosp Univ Santiago de Compostela, Fdn IDICHUS IDIS, Santiago De Compostela, Spain, Email: pablo.aguiar.fernandez@sergas.es
Corporate Author Thesis
Publisher Amer Assoc Physicists Medicine Amer Inst Physics Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0094-2405 ISBN Medium
Area Expedition Conference
Notes ISI:000283747600015 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 338
Permanent link to this record
 

 
Author (up) Asai, M.; Cortes-Giraldo, M.A.; Gimenez-Alventosa, V.; Gimenez, V.; Salvat, F.
Title The PENELOPE Physics Models and Transport Mechanics. Implementation into Geant4 Type Journal Article
Year 2021 Publication Frontiers in Physics Abbreviated Journal Front. Physics
Volume 9 Issue Pages 738735 - 20pp
Keywords coupled electron-photon transport; Monte Carlo simulation; PENELOPE code system; random-hinge method; Geant4 toolkit
Abstract A translation of the penelope physics subroutines to C++, designed as an extension of the Geant4 toolkit, is presented. The Fortran code system penelope performs Monte Carlo simulation of coupled electron-photon transport in arbitrary materials for a wide energy range, nominally from 50 eV up to 1 GeV. Penelope implements the most reliable interaction models that are currently available, limited only by the required generality of the code. In addition, the transport of electrons and positrons is simulated by means of an elaborate class II scheme in which hard interactions (involving deflection angles or energy transfers larger than pre-defined cutoffs) are simulated from the associated restricted differential cross sections. After a brief description of the interaction models adopted for photons and electrons/positrons, we describe the details of the class-II algorithm used for tracking electrons and positrons. The C++ classes are adapted to the specific code structure of Geant4. They provide a complete description of the interactions and transport mechanics of electrons/positrons and photons in arbitrary materials, which can be activated from the G4ProcessManager to produce simulation results equivalent to those from the original penelope programs. The combined code, named PenG4, benefits from the multi-threading capabilities and advanced geometry and statistical tools of Geant4.
Address [Asai, Makoto] SLAC Natl Accelerator Lab, Menlo Pk, CA USA, Email: miancortes@us.es;
Corporate Author Thesis
Publisher Frontiers Media Sa Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2296-424x ISBN Medium
Area Expedition Conference
Notes WOS:000742889400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5080
Permanent link to this record
 

 
Author (up) Assam, I.; Vijande, J.; Ballester, F.; Perez-Calatayud, J.; Poppe, B.; Siebert, F.A.
Title Evaluation of dosimetric effects of metallic artifact reduction and tissue assignment on Monte Carlo dose calculations for I-125 prostate implants Type Journal Article
Year 2022 Publication Medical Physics Abbreviated Journal Med. Phys.
Volume 49 Issue Pages 6195-6208
Keywords metallic artifact reduction; Monte Carlo dosimetry; post-implant CT; prostate brachytherapy; tissue assignment schemes; voxelized virtual patient model
Abstract Purpose Monte Carlo (MC) simulation studies, aimed at evaluating the magnitude of tissue heterogeneity in I-125 prostate permanent seed implant brachytherapy (BT), customarily use clinical post-implant CT images to generate a virtual representation of a realistic patient model (virtual patient model). Metallic artifact reduction (MAR) techniques and tissue assignment schemes (TAS) are implemented on the post-implant CT images to mollify metallic artifacts due to BT seeds and to assign tissue types to the voxels corresponding to the bright seed spots and streaking artifacts, respectively. The objective of this study is to assess the combined influence of MAR and TAS on MC absorbed dose calculations in post-implant CT-based phantoms. The virtual patient models used for I-125 prostate implant MC absorbed dose calculations in this study are derived from the CT images of an external radiotherapy prostate patient without BT seeds and prostatic calcifications, thus averting the need to implement MAR and TAS. Methods The geometry of the IsoSeed I25.S17plus source is validated by comparing the MC calculated results of the TG-43 parameters for the line source approximation with the TG-43U1S2 consensus data. Four MC absorbed dose calculations are performed in two virtual patient models using the egs_brachy MC code: (1) TG-43-based D-w,w-TG(43), (2) D-w,D-w-MBDC that accounts for interseed scattering and attenuation (ISA), (3) D-m,D-m that examines ISA and tissue heterogeneity by scoring absorbed dose in tissue, and (4) D-w,D-m that unlike D-m,D-m scores absorbed dose in water. The MC absorbed doses (1) and (2) are simulated in a TG-43 patient phantom derived by assigning the densities of every voxel to 1.00 g cm(-3) (water), whereas MC absorbed doses (3) and (4) are scored in the TG-186 patient phantom generated by mapping the mass density of each voxel to tissue according to a CT calibration curve. The MC absorbed doses calculated in this study are compared with VariSeed v8.0 calculated absorbed doses. To evaluate the dosimetric effect of MAR and TAS, the MC absorbed doses of this work (independent of MAR and TAS) are compared to the MC absorbed doses of different I-125 source models from previous studies that were calculated with different MC codes using post-implant CT-based phantoms generated by implementing MAR and TAS on post-implant CT images. Results The very good agreement of TG-43 parameters of this study and the published consensus data within 3% validates the geometry of the IsoSeed I25.S17plus source. For the clinical studies, the TG-43-based calculations show a D-90 overestimation of more than 4% compared to the more realistic MC methods due to ISA and tissue composition. The results of this work generally show few discrepancies with the post-implant CT-based dosimetry studies with respect to the D-90 absorbed dose metric parameter. These discrepancies are mainly Type B uncertainties due to the different I-125 source models and MC codes. Conclusions The implementation of MAR and TAS on post-implant CT images have no dosimetric effect on the I-125 prostate MC absorbed dose calculation in post-implant CT-based phantoms.
Address [Assam, Isong; Siebert, Frank-Andre] UKSH, Clin Radiotherapy Radiooncol, Campus Kiel, Kiel, Germany, Email: Isong.Assam@uksh.de
Corporate Author Thesis
Publisher Wiley Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0094-2405 ISBN Medium
Area Expedition Conference
Notes WOS:000835807200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5321
Permanent link to this record
 

 
Author (up) ATLAS Collaboration (Aad, G. et al); Amoros, G.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Kaci, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Miñano, M.; Mitsou, V.A.; Moles-Valls, R.; Moreno Llacer, M.; Oliver Garcia, E.; Perez Garcia-Estañ, M.T.; Ros, E.; Salt, J.; Solans, C.A.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M.; Wildauer, A.
Title Measurement of the transverse momentum distribution of Z/gamma* bosons in proton-proton collisions at sqrt(s)=7 TeV with the ATLAS detector Type Journal Article
Year 2011 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 705 Issue 5 Pages 415-434
Keywords Z bosons; Differential cross section; Perturbative QCD; Event generators; Monte Carlo models
Abstract A measurement of the Z/gamma* transverse momentum (p(T)(Z)) distribution in proton-proton collisions at sqrt(s) = 7 TeV is presented using Z/gamma* -> e(+)e(-) and Z/gamma* -> mu(+)mu(-) decays collected with the ATLAS detector in data sets with integrated luminosities of 35 pb(-1) and 40 pb(-1), respectively. The normalized differential cross sections are measured separately for electron and muon decay channels as well as for their combination up to pi of 350 GeV for invariant dilepton masses 66 GeV < m(ll) < 116 GeV. The measurement is compared to predictions of perturbative QCD and various event generators. The prediction of resummed QCD combined with fixed order perturbative QCD is found to be in good agreement with the data.
Address [Akdogan, T.; Arik, E.; Arik, M.; Istin, S.; Ozcan, V. E.; Rador, T.] Bogazici Univ, Dept Phys, Istanbul, Turkey
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000297490400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 840
Permanent link to this record
 

 
Author (up) ATLAS Collaboration (Aad, G. et al); Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Fassi, F.; Ferrer, A.; Fiorini, L.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Kaci, M.; Lacasta, C.; Lacuesta, V.R.; March, L.; Marti-Garcia, S.; Miñano, M.; Mitsou, V.A.; Moles-Valls, R.; Moreno Llacer, M.; Oliver Garcia, E.; Pedraza Lopez, S.; Perez Garcia-Estañ, M.T.; Romero Adam, E.; Ros, E.; Salt, J.; Sanchez Martinez, V.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M.
Title Measurement of angular correlations in Drell-Yan lepton pairs to probe Z/gamma* boson transverse momentum at root s=7 TeV with the ATLAS detector Type Journal Article
Year 2013 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 720 Issue 1-3 Pages 32-51
Keywords Z boson; Differential cross section; Perturbative QCD; Event generators; Monte Carlo models
Abstract A measurement of angular correlations in Drell-Yan lepton pairs via the phi(eta)* observable is presented. This variable probes the same physics as the Z/gamma* boson transverse momentum with a better experimental resolution. The Z/gamma* -> e(+)e(-) and Z/gamma* -> mu(+)mu(-) decays produced in proton-proton collisions at a centre-of-mass energy of root s = 7 TeV are used. The data were collected with the ATLAS detector at the LHC and correspond to an integrated luminosity of 4.6 fb(-1). Normalised differential cross sections as a function of phi(eta)* are measured separately for electron and muon decay channels. These channels are then combined for improved accuracy. The cross section is also measured double differentially as a function of phi(eta)* for three independent bins of the Z boson rapidity. The results are compared to QCD calculations and to predictions from different Monte Carlo event generators. The data are reasonably well described, in all measured Z boson rapidity regions, by resummed QCD predictions combined with fixed-order perturbative QCD calculations or by some Monte Carlo event generators. The measurement precision is typically better by one order of magnitude than present theoretical uncertainties.
Address [Aad, G.; Ahles, F.; Amoroso, S.; Barber, T.; Bernhard, R.; Boehler, M.; Bruneliere, R.; Christov, A.; Consorti, V.; Fehling-Kaschek, M.; Flechl, M.; Hartert, J.; Herten, G.; Horner, S.; Jakobs, K.; Janus, M.; Kononov, A. I.; Kopp, A. K.; Kuehn, S.; Lai, S.; Landgraf, U.; Lohwasser, K.; Ludwig, I.; Ludwig, J.; Mahboubi, K.; Mohr, W.; Nilsen, H.; Parzefall, U.; Rammensee, M.; Rave, T. C.; Rurikova, Z.; Ruthmann, N.; Schmidt, E.; Schumacher, M.; Siegert, F.; Stoerig, K.; Sundermann, J. E.; Temming, K. K.; Thoma, S.; Tsiskaridze, V.; Venturi, M.; Vivarelli, I.; von Radziewski, H.; Anh, T. Vu; Warsinsky, M.; Weiser, C.; Werner, M.; Winkelmann, S.; Xie, S.; Zimmermann, S.] Univ Freiburg, Fak Math & Phys, D-79106 Freiburg, Germany, Email: atlas.publications@cern.ch
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000316513500004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1389
Permanent link to this record
 

 
Author (up) ATLAS Collaboration (Adragna, P. et al); Castelo, J.; Castillo Gimenez, V.; Cuenca, C.; Ferrer, A.; Fullana, E.; Gonzalez, V.; Higon-Rodriguez, E.; Poveda, J.; Ruiz, A.; Salvachua, B.; Sanchis, E.; Solans, C.; Torres, J.; Valero, A.; Valls Ferrer, J.A.
Title Measurement of pion and proton response and longitudinal shower profiles up to 20 nuclear interaction lengths with the ATLAS Tile calorimeter Type Journal Article
Year 2010 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 615 Issue 2 Pages 158-181
Keywords Calorimeter; Test-beam; ATLAS; Monte Carlo simulation; GEANT4; Hadronic shower development; Pion-proton response; Longitudinal shower profile for hadrons
Abstract The response of pions and protons in the energy range of 20-180 GeV, produced at CERN's SPS H8 test-beam line in the ATLAS iron-scintillator Tile hadron calorimeter, has been measured. The test-beam configuration allowed the measurement of the longitudinal shower development for pions and protons up to 20 nuclear interaction lengths. It was found that pions penetrate deeper in the calorimeter than protons. However, protons induce showers that are wider laterally to the direction of the impinging particle. Including the measured total energy response, the pion-to-proton energy ratio and the resolution, all observations are consistent with a higher electromagnetic energy fraction in pion-induced showers. The data are compared with GEANT4 simulations using several hadronic physics lists. The measured longitudinal shower profiles are described by an analytical shower parametrization within an accuracy of 5-10%. The amount of energy leaking out behind the calorimeter is determined and parametrized as a function of the beam energy and the calorimeter depth. This allows for a leakage correction of test-beam results in the standard projective geometry.
Address [Hakobyan, H.; Simonyan, M.] Yerevan Phys Inst, Yerevan 375036, Armenia, Email: Margar.Simonyan@cern.ch
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes ISI:000276299900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 252
Permanent link to this record
 

 
Author (up) Ballester, F.; Tedgren, A.C.; Granero, D.; Haworth, A.; Mourtada, F.; Fonseca, G.P.; Zourari, K.; Papagiannis, P.; Rivard, M.J.; Siebert, F.A.; Sloboda, R.S.; Smith, R.L.; Thomson, R.M.; Verhaegen, F.; Vijande, J.; Ma, Y.Z.; Beaulieu, L.
Title A generic high-dose rate Ir-192 brachytherapy source for evaluation of model-based dose calculations beyond the TG-43 formalism Type Journal Article
Year 2015 Publication Medical Physics Abbreviated Journal Med. Phys.
Volume 42 Issue 6 Pages 3048-3062
Keywords Ir-192; HDR brachytherapy; Monte Carlo methods; model-based dose calculation; TG-186
Abstract Purpose: In order to facilitate a smooth transition for brachytherapy dose calculations from the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) formalism to model-based dose calculation algorithms (MBDCAs), treatment planning systems (TPSs) using a MBDCA require a set of well-defined test case plans characterized by Monte Carlo (MC) methods. This also permits direct dose comparison to TG-43 reference data. Such test case plans should be made available for use in the software commissioning process performed by clinical end users. To this end, a hypothetical, generic high-dose rate (HDR) Ir-192 source and a virtual water phantom were designed, which can be imported into a TPS. Methods: A hypothetical, generic HDR Ir-192 source was designed based on commercially available sources as well as a virtual, cubic water phantom that can be imported into any TPS in DICOM format. The dose distribution of the generic Ir-192 source when placed at the center of the cubic phantom, and away from the center under altered scatter conditions, was evaluated using two commercial MBDCAs [Oncentra (R) Brachy with advanced collapsed-cone engine (ACE) and BrachyVision AcuRos (TM)]. Dose comparisons were performed using state-of-the-art MC codes for radiation transport, including ALGEBRA, BrachyDose, GEANT4, MCNP5, MCNP6, and pENELopE2008. The methodologies adhered to recommendations in the AAPM TG-229 report on high-energy brachytherapy source dosimetry. TG-43 dosimetry parameters, an along-away dose-rate table, and primary and scatter separated (PSS) data were obtained. The virtual water phantom of (201)(3) voxels (1 mm sides) was used to evaluate the calculated dose distributions. Two test case plans involving a single position of the generic HDR Ir-192 source in this phantom were prepared: (i) source centered in the phantom and (ii) source displaced 7 cm laterally from the center. Datasets were independently produced by different investigators. MC results were then compared against dose calculated using TG-43 and MBDCA methods. Results: TG-43 and PSS datasets were generated for the generic source, the PSS data for use with the ACE algorithm. The dose-rate constant values obtained from seven MC simulations, performed independently using different codes, were in excellent agreement, yielding an average of 1.1109 +/- 0.0004 cGy/(h U) (k = 1, Type A uncertainty). MC calculated dose-rate distributions for the two plans were also found to be in excellent agreement, with differences within type A uncertainties. Differences between commercial MBDCA and MC results were test, position, and calculation parameter dependent. On average, however, these differences were within 1% for ACUROS and 2% for ACE at clinically relevant distances. Conclusions: A hypothetical, generic HDR Ir-192 source was designed and implemented in two commercially available TPSs employing different MBDCAs. Reference dose distributions for this source were benchmarked and used for the evaluation of MBDCA calculations employing a virtual, cubic water phantom in the form of a CT DICOM image series. The implementation of a generic source of identical design in all TPSs using MBDCAs is an important step toward supporting univocal commissioning procedures and direct comparisons between TPSs.
Address [Ballester, Facundo] Univ Valencia, Dept Atom Mol & Nucl Phys, E-46100 Burjassot, Spain, Email: Facundo.Ballester@uv.es
Corporate Author Thesis
Publisher Amer Assoc Physicists Medicine Amer Inst Physics Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0094-2405 ISBN Medium
Area Expedition Conference
Notes WOS:000356998300031 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2315
Permanent link to this record