Proton CT setup at CV-28 of IEN/CNEN

Evseev, Ivan; Assis, Joaquim Teixeira de; Yevseyeva, Olga; Filho, U. M. Vinagre; Setti, João Antônio Palma; Schelin, H.R.; Paschuk, S.A.; Klock, Margio Cezar Loss; Schulte, R.; Lopes, Ricardo Tadeu

doi:10.1590/s0103-97332005000500006

Cited by 2 publications

(3 citation statements)

References 6 publications

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“…Within the Bethe-Bloch domain, the question is almost energy and material independent: the energy-range relations are practically identical if the reduced units for the energy and passed thickness are used [5], [13]. That is why we could take the 19,68MeV proton data from [14] as the experimental reference without losing the validity of the presented analysis.…”

Section: Monte Carlo Simulationsmentioning

confidence: 99%

GEANT4 Tuning For pCT Development

Yevseyeva¹,

Assis²,

Evseev³

et al. 2011

AIP Conference Proceedings

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Abstract. Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Thus, the fidelity of proton computed tomography (pCT) simulations as a tool for proton therapy planning depends in the general case on the accuracy of results obtained for the proton interaction with thick absorbers. GEANT4 simulations of proton energy spectra after passing thick absorbers do not agree well with existing experimental data, as showed previously. Moreover, the spectra simulated for the Bethe-Bloch domain showed an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 version 8.2 during our simulations for pCT. This work describes in more details the simulations of the proton passage through aluminum absorbers with varied thickness. The simulations were done by modifying only the geometry in the Hadrontherapy Example, and for all available choices of the Electromagnetic Physics Models. As the most probable reasons for these effects is some specific feature in the code, or some specific implicit parameters in the GEANT4 manual, we continued our study with version 9.2 of the code. Some improvements in comparison with our previous results were obtained. The simulations were performed considering further applications for pCT development. The interest in proton computed tomography (pCT) development is now reopened with the spread of the proton beam treatment [1]. The idea is to use the same medical proton therapy beam for diagnosis with pCT, i.e. for tumor localization and data acquisition for further irradiation planning. Potentially it can improve the quality of proton therapy and decrease the dose delivered to patients. The Monte Carlo simulations have a successful history in varied fields of study and could also be a helpful instrument in the case of pCT.

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Section: Monte Carlo Simulationsmentioning

confidence: 99%

GEANT4 Tuning For pCT Development

Yevseyeva¹,

Assis²,

Evseev³

et al. 2011

AIP Conference Proceedings

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“…Monte Carlo simulations of parallel pCT projections of a simple phantom, selected for initial studies, were performed with GEANT4 to evaluate the anticipated equipment performance of the experimental setup at CV-28 [23,24]. The phantom has a general structure similar to that described in [12]: a glass tube (borosilicate [46]: ȡ=2.23g/cm 3 ) with 5mm external and 4mm internal diameter with a 1mm diameter polyethylene rod (Marlex [46]: ȡ=0.93g/cm 3 ) along the central axis, and filled with pure water.…”

Section: Simulation Of Initial Pct Experiments At Cv-28 Of Ien/cnenmentioning

confidence: 99%

“…However, the pCT technique still requires more basic research before it becomes a routine service. In this work, we describe Monte Carlo simulations in preparation of auxiliary pCT experiments on Line#3 at CV-28 of IEN/CNEN in Rio de Janeiro, Brazil, using 25 MeV protons [23,24]. It will be shown that these measurements, despite the low energy used, can closely reproduce some aspects of pCT measurements at higher energies (~250MeV) in preparation at the proton treatment center in Loma Linda, USA.…”

Section: Introductionmentioning

confidence: 99%

The density measurements in pCT imaging

Evseev¹,

Assis²,

Yevseyeva³

et al. 2005

Medical Imaging 2005: Physics of Medical Imaging

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In existing proton treatment centers, dose calculations are performed based on x-ray computerized tomography (CT). Alternatively, the therapeutic proton beam could be used to collect the data for treatment planning via proton CT (pCT). With the development of medical proton gantries, first at Loma Linda University Medical Center and now in several other proton treatment centers, it is of interest to continue the early pCT investigations of the 1970s and the early 1980s. From that time, the basic idea of the pCT method has advanced from average energy loss measurements to an individual proton tracking technique. This reduces the image degradation due to multiple Coulomb scattering. Thereby, the central pCT problem shifts to the fidelity of the physical information obtained about the scanned patient, which will be used for proton treatment planning. The accuracy of relative electron density distributions extracted from pCT images was investigated in this work using continuous slowing down approximation (CSDA) and water-equivalent-thickness (WET) concepts. Analytical results were checked against Monte Carlo simulations, which were obtained with SRIM2003 and GEANT4 Monte Carlo software packages. The range of applications and the sources of absolute errors are discussed.

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Proton CT setup at CV-28 of IEN/CNEN

Cited by 2 publications

References 6 publications

GEANT4 Tuning For pCT Development

GEANT4 Tuning For pCT Development

The density measurements in pCT imaging

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