Proof of principle of helium‐beam radiography using silicon pixel detectors for energy deposition measurement, identification, and tracking of single ions

Gehrke, Tim; Gallas, Raya R.; Jäkel, Oliver; Martišíková, M.

doi:10.1002/mp.12723

Cited by 27 publications

(29 citation statements)

References 56 publications

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“…While the investigations were so far mainly focused on the clinically available proton and carbon ion beams, recent studies have started addressing, both theoretically and experimentally, the potential of other ion beams being (re)considered for clinical introduction in the near future, particularly given the independence of the SPR needed for treatment planning on the imaging ion species. In this respect, helium ions are regarded as a very promising candidate, owing to their reduced lateral scattering compared to protons, and reduced imaging dose (at the same image quality) compared to carbon ions 36–39 . In particular, Volz et al 38 confirmed experimentally almost a factor of two increased spatial resolution of 4 He ion radiography compared to proton radiography, as acquired with the same second generation prototype of refs.…”

Section: General Purpose Techniquesmentioning

confidence: 99%

In vivo range verification in particle therapy

2018

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Exploitation of the full potential offered by ion beams in clinical practice is still hampered by several sources of treatment uncertainties, particularly related to limitations of our ability to locate the position of the Bragg peak in the tumour. To this end, several efforts are ongoing to improve the characterization of patient position, anatomy and tissue stopping power properties prior to treatment, as well as to enable in-vivo verification of the actual dose delivery, or at least beam range, during or shortly after treatment. This contribution critically reviews methods under development or clinical testing for verification of ion therapy, based on pre-treatment range and tissue probing as well as detection of secondary emissions or physiological changes during and after treatment, trying to disentangle approaches of general applicability from those more specific to certain anatomical locations. Moreover, it discusses future directions, which could benefit from integration of multiple modalities or address novel exploitation of the measurable signals for biologically adapted therapy.

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Section: General Purpose Techniquesmentioning

confidence: 99%

In vivo range verification in particle therapy

2018

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“…Therefore, ion imaging requires sophisticated detector systems, capable of measuring particle track information and residual energy/range on a single-event basis (Schulte et al 2008). To date, several different prototype systems have been developed (Bashkirov et al 2009, Seco & Depauw 2011, Talamonti et al 2012, Uzunyan et al 2015, Bashkirov et al 2016a, Price 2016, Pettersen et al 2017, Gehrke et al 2017).…”

Section: Introductionmentioning

confidence: 99%

The impact of secondary fragments on the image quality of helium ion imaging

et al. 2018

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Single-event ion imaging enables the direct reconstruction of the relative stopping power (RSP) information required for ion-beam therapy. Helium ions were recently hypothesized to be the optimal species for such technique. The purpose of this work is to investigate the effect of secondary fragments on the image quality of helium CT (HeCT) and to assess the performance of a prototype proton CT (pCT) scanner when operated with helium beams in Monte Carlo simulations and experiment. Experiments were conducted installing the U.S. pCT consortium prototype scanner at the Heidelberg Ion-Beam Therapy Center (HIT). Simulations were performed with the scanner using the TOPAS toolkit. HeCT images were reconstructed for a cylindrical water phantom, the CTP404 (sensitometry), and the CTP528 (line-pair) [Formula: see text] modules. To identify and remove individual events caused by fragmentation, the multistage energy detector of the scanner was adapted to function as a [Formula: see text] telescope. The use of the developed filter eliminated the otherwise arising ring artifacts in the HeCT reconstructed images. For the HeCT reconstructed images of a water phantom, the maximum RSP error was improved by almost a factor 8 with respect to unfiltered images in the simulation and a factor 10 in the experiment. Similarly, for the CTP404 module, the mean RSP accuracy improved by a factor 6 in both the simulation and the experiment when the filter was applied (mean relative error 0.40% in simulation, 0.45% in experiment). In the evaluation of the spatial resolution through the CTP528 module, the main effect of the filter was noise reduction. For both simulated and experimental images the spatial resolution was ∼4 lp cm. In conclusion, the novel filter developed for secondary fragments proved to be effective in improving the visual quality and RSP accuracy of the reconstructed images. With the filter, the pCT scanner is capable of accurate HeCT imaging.

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“…In recent years, along with protons, heavier ions (mostly helium or carbon) have been considered for imaging given their smaller deviation due to multiple Coulomb scattering. The expected effect of an improved spatial resolution was observed, once the ion fragmentation was taken into account [25][26][27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 90%

A High-Granularity Digital Tracking Calorimeter Optimized for Proton CT

Alme¹,

Barnaföldi²,

Barthel³

et al. 2020

Front. Phys.

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A typical proton CT (pCT) detector comprises a tracking system, used to measure the proton position before and after the imaged object, and an energy/range detector to measure the residual proton range after crossing the object. The Bergen pCT collaboration was established to design and build a prototype pCT scanner with a high granularity digital tracking calorimeter used as both tracking and energy/range detector. In this work the conceptual design and the layout of the mechanical and electronics implementation, along with Monte Carlo simulations of the new pCT system are reported. The digital tracking calorimeter is a multilayer structure with a lateral aperture of 27 cm × 16.6 cm, made of 41 detector/absorber sandwich layers (calorimeter), with aluminum (3.5 mm) used both as absorber and carrier, and two additional layers used as tracking system (rear trackers) positioned downstream of the imaged object; no tracking upstream the object is included. The rear tracker's structure only differs from the calorimeter layers for the carrier made of ∼200 μm carbon fleece and carbon paper (carbon-epoxy sandwich), to minimize scattering. Each sensitive layer consists of 108 ALICE pixel detector (ALPIDE) chip sensors (developed for ALICE, CERN) bonded on a polyimide flex and subsequently bonded to a larger flexible printed circuit board. Beam tests tailored to the pCT operation have been performed using high-energetic (50-220 MeV/u) proton and ion beams at the

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Proof of principle of helium‐beam radiography using silicon pixel detectors for energy deposition measurement, identification, and tracking of single ions

Cited by 27 publications

References 56 publications

In vivo range verification in particle therapy

In vivo range verification in particle therapy

The impact of secondary fragments on the image quality of helium ion imaging

A High-Granularity Digital Tracking Calorimeter Optimized for Proton CT

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