Patient positioning for protontherapy using a proton range telescope

Romero, J. L.; Osborn, James; Brady, F.P.; Caskey, W.; Cebra, D.; Partlan, M. D.; Kusko, Bruce H.; King, R. S. B.; Mirshad, I.; Kubo, Hideo; Daftari, Inder K.; Chu, W. T.

doi:10.1016/0168-9002(94)01353-5

Cited by 19 publications

(17 citation statements)

References 12 publications

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“…It contains four groups of rectangular inserts composed of three different tissue-equivalent polymers representing enamel (RSP = 1.770), adult cortical bone (RSP = 1.685), and lung (RSP = 0.217), as well as air (RSP = 0.007). The inserts are completely contained within the body of the phantom and have dimensions of 15×15×45 mm 3 . The centers of the inserts are positioned at radii of 25, 55, and 80 mm, respectively, such that their innermost and outermost edges are orthogonal to the radius of the cylinder.…”

Section: B Custom Edge Phantommentioning

confidence: 99%

“…The recent increase in the number of proton therapy facilities, and the lack of imaging support for proton therapy in the treatment room, has led to a renewed interest in proton radiography and CT for improved range definition and treatment verification. [1][2][3] The present procedure for proton therapy planning involves converting the Hounsfield value of each voxel in x-ray CT planning scans of the patient into proton stopping power via a stoichiometrically acquired calibration curve. However, since there is no unique relationship between Hounsfield values and proton stopping power, this procedure has inherent uncertainties of a few percent in the proton range, requiring additional distal uncertainty margins in proton treatment plans.…”

Section: Introductionmentioning

confidence: 99%

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An evaluation of spatial resolution of a prototype proton CT scanner

et al. 2016

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Purpose: To evaluate the spatial resolution of proton CT using both a prototype proton CT scanner and Monte Carlo simulations. Methods: A custom cylindrical edge phantom containing twelve tissue-equivalent inserts with four different compositions at varying radial displacements from the axis of rotation was developed for measuring the modulation transfer function (MTF) of a prototype proton CT scanner. Two scans of the phantom, centered on the axis of rotation, were obtained with a 200 MeV, low-intensity proton beam: one scan with steps of 4• , and one scan with the phantom continuously rotating. In addition, Monte Carlo simulations of the phantom scan were performed using scanners idealized to various degrees. The data were reconstructed using an iterative projection method with added total variation superiorization based on individual proton histories. Edge spread functions in the radial and azimuthal directions were obtained using the oversampling technique. These were then used to obtain the modulation transfer functions. The spatial resolution was defined by the 10% value of the modulation transfer function (MTF 10% ) in units of line pairs per centimeter (lp/cm). Data from the simulations were used to better understand the contributions of multiple Coulomb scattering in the phantom and the scanner hardware, as well as the effect of discretization of proton location. Results: The radial spatial resolution of the prototype proton CT scanner depends on the total path length, W , of the proton in the phantom, whereas the azimuthal spatial resolution depends both on W and the position, u − , at which the most-likely path uncertainty is evaluated along the path. For protons contributing to radial spatial resolution, W varies with the radial position of the edge, whereas for protons contributing to azimuthal spatial resolution, W is approximately constant. For a pixel size of 0.625 mm, the radial spatial resolution of the image reconstructed from the fully idealized simulation data ranged between 6.31 ± 0.36 lp/cm for W = 197 mm i.e., close to the center of the phantom, and 13.79 ± 0.36 lp/cm for W = 97 mm, near the periphery of the phantom. The azimuthal spatial resolution ranged from 6.99 ± 0.23 lp/cm at u − = 75 mm (near the center) to 11.20 ± 0.26 lp/cm at u − = 20 mm (near the periphery). Multiple Coulomb scattering limits the radial spatial resolution for path lengths greater than approximately 130 mm, and the azimuthal spatial resolution for positions of evaluation greater than approximately 40 mm for W = 199 mm. The radial spatial resolution of the image reconstructed from data from the 4• stepped experimental scan ranged from 5.11 ± 0.61 lp/cm for W = 197 mm to 8.58 ± 0.50 lp/cm for W = 97 mm. In the azimuthal direction, the spatial resolution ranged from 5.37 ± 0.40 lp/cm at u − = 75 mm to 7.27 ± 0.39 lp/cm at u − = 20 mm. The continuous scan achieved the same spatial resolution as that of the stepped scan.

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Section: B Custom Edge Phantommentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An evaluation of spatial resolution of a prototype proton CT scanner

et al. 2016

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“…The benefit of proton imaging for patient positioning has been stressed long ago39. Also for such an application, a PM installed at a fixed position downstream of the patient and outside the treatment room could be used.…”

Section: Discussionmentioning

confidence: 99%

“…There are various applications of proton imaging40. The benefit for patient positioning has been stressed long ago39. It should be clear that accurate patient positioning is mandatory in a high-dose treatment.…”

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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“…A high energy proton beam can accurately deliver a precise radiation dose to the lesion while minimizing the dose to the surrounding tissue. The success of PRT is based on the precision with which the dose is deposited in the tumor volume [16]. Neutron tracking detectors can also be employed to accurately locate nuclear materials (waste, spills).…”

Section: Daniel Holslin Aaron Polichar Janis Baltgalvismentioning

confidence: 99%