Quantitative proton radiography of an animal patient

Schneider, Uwe; Dellert, M.; Pedroni, E.; Pemler, P.; Besserer, Jürgen; Moosburger, M.; Theiler, Prisca; Kaser‐Hotz, Barbara

doi:10.1117/12.479946

Cited by 4 publications

(5 citation statements)

References 9 publications

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“…The range telescope, as well as the range shifter plates, were calibrated into water equivalent thickness. 12 The sensitive area of the radiographic apparatus was 3 cmϫ20 cm. The images were produced by scanning the beam by magnetic deflection ͑20 cm͒ in one direction and by moving the patient table in the other direction perpendicular to the beam.…”

Section: Methodsmentioning

confidence: 99%

“…The detailed calibration process is described elsewhere. 12 For each scan all range shifters were put successively into the beam path to determine the position of the range spectrum in range telescope plates as a function of the additional absorbing material ͑number of range shifter plates͒ and the water level.…”

Section: Methodsmentioning

confidence: 99%

“…Additionally, the range telescope was calibrated into water equivalent thickness. 12 We analyzed the radiography scans of the homogeneous water phantom in order to determine the density resolution. For this purpose we calculated the standard deviation of all pixel of the calibrated ''water images'' ͑0-160 mm͒ from the nominal water levels.…”

Section: A Density Resolutionmentioning

confidence: 99%

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First proton radiography of an animal patient

et al. 2004

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The purpose of this work is to show the feasibility of proton radiography in terms of radiation dose, imaging speed, image quality (density and spatial resolution), and image content under clinical conditions. Protons with 214 MeV energy can penetrate through most patients and were used for imaging. The measured residual range (or energy) of the protons behind the patient was subtracted from the range without an object in the beam path and used to create a projected image. The image content is therefore proportional to the range that protons have lost in the patient. We took proton images of the head of a dog after it received proton radiotherapy treatment of a nasal tumor. The spatial resolution by measuring for each proton separately its coordinate in front of and behind the patient was approximately 1 mm. The acquisition time was on the order of several seconds and was limited by the patient table movement. The range sensitivity of the images was approximately 0.6 mm, which is good enough to use the images for therapy range verification. The dose that the dog received during exposure was 0.03 mGy, which is approximately a factor 50-100 smaller than for a comparable x-ray image. The potential to obtain quantitative images of proton ranges with satisfying spatial and range resolution and low dose to the patient suggests that proton radiography should be applied to patients who are under proton radiotherapy treatment.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: A Density Resolutionmentioning

confidence: 99%

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First proton radiography of an animal patient

et al. 2004

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“…It has already been emphasized in the literature that as it has become standard to perform routine imaging of the treatment beam in photon therapy it will be the same in proton therapy too 10 . There are various applications of proton imaging 40 . The benefit for patient positioning has been stressed long ago 39 .…”

Section: Discussionmentioning

confidence: 99%

High-energy proton imaging for biomedical applications

Prall

Durante

Berger

et al. 2016

Sci Rep

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The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allows imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. Tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.

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“…Based on experiments using water bath, the spatial resolution achieved for the residual range image is ϳ1 mm and the density resolution was 0.3%. In 2003 and 2005, Schneider et al 21,22 extended the test of their system to a dog patient. Proton beams at 214 MeV were used and the range and range dilution information were analyzed.…”

Section: Introductionmentioning

confidence: 99%

Proton radiography and fluoroscopy of lung tumors: A Monte Carlo study using patient‐specific 4DCT phantoms

Han

Chen

2011

Medical Physics

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Purpose: Monte Carlo methods are used to simulate and optimize a time-resolved proton range telescope ͑TRRT͒ in localization of intrafractional and interfractional motions of lung tumor and in quantification of proton range variations. Methods: The Monte Carlo N-Particle eXtended ͑MCNPX͒ code with a particle tracking feature was employed to evaluate the TRRT performance, especially in visualizing and quantifying proton range variations during respiration. Protons of 230 MeV were tracked one by one as they pass through position detectors, patient 4DCT phantom, and finally scintillator detectors that measured residual ranges. The energy response of the scintillator telescope was investigated. Mass density and elemental composition of tissues were defined for 4DCT data. Results: Proton water equivalent length ͑WEL͒ was deduced by a reconstruction algorithm that incorporates linear proton track and lateral spatial discrimination to improve the image quality. 4DCT data for three patients were used to visualize and measure tumor motion and WEL variations. The tumor trajectories extracted from the WEL map were found to be within ϳ1 mm agreement with direct 4DCT measurement. Quantitative WEL variation studies showed that the proton radiograph is a good representation of WEL changes from entrance to distal of the target. Conclusions: MCNPX simulation results showed that TRRT can accurately track the motion of the tumor and detect the WEL variations. Image quality was optimized by choosing proton energy, testing parameters of image reconstruction algorithm, and comparing to ground truth 4DCT. The future study will demonstrate the feasibility of using the time resolved proton radiography as an imaging tool for proton treatments of lung tumors.

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Quantitative proton radiography of an animal patient

Cited by 4 publications

References 9 publications

First proton radiography of an animal patient

First proton radiography of an animal patient

High-energy proton imaging for biomedical applications

Proton radiography and fluoroscopy of lung tumors: A Monte Carlo study using patient‐specific 4DCT phantoms

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