Acoustic pulse generation in excised muscle by pulsed proton beam irradiation and the possibility of clinical application to radiation therapy.

Hayakawa, Yoshinori; Tada, Junichiro; Inada, Tomohiro; Kitagawa, Toshio; Wagai, Toshio; Yosioka, Katuya

doi:10.1250/ast.9.255

Cited by 14 publications

(15 citation statements)

References 4 publications

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“…Sulak et al experimentally detected acoustic signals produced by proton beams in fluid media and successfully demonstrated a thermal expansion model for this phenomenon . Hayakawa et al detected acoustic pulse signals in animal tissues and humans, demonstrating the feasibility of determining dose distribution in proton therapy . A 3D dosimetric scanner based on ionizing radiation‐induced acoustic computed tomography (RACT) was theoretically designed to verify dose distribution and proton range in a water phantom .…”

Section: Introductionmentioning

confidence: 99%

“…15 Hayakawa et al detected acoustic pulse signals in animal tissues and humans, demonstrating the feasibility of determining dose distribution in proton therapy. [22][23][24] A 3D dosimetric scanner based on ionizing radiation-induced acoustic computed tomography (RACT) was theoretically designed to verify dose distribution and proton range in a water phantom. 25 A clinical ultrasound array was deployed to localize the proton Bragg peak from reconstructed thermoacoustic images in water and gelatin phantoms, which provided perfectly co-registered overlay of the Bragg peak onto a standard ultrasound image acquired by the same ultrasound array, and overcame the presence of acoustic heterogeneity and speed of sound errors.…”

Section: Introductionmentioning

confidence: 99%

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Simulation studies of time reversal‐based protoacoustic reconstruction for range and dose verification in proton therapy

Yu¹,

Li²,

Zhang³

et al. 2019

Medical Physics

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Purpose In vivo range verification in proton therapy is a critical step to help minimize range and dose uncertainty. We propose to employ a time reversal (TR)‐based approach using proton‐induced acoustics (protoacoustics) to reconstruct pressure/dose distribution in heterogeneous tissues. Methods The dose distribution of mono‐energetic proton pencil beam in a CT‐based patient phantom was calculated by Monte Carlo simulation. K‐wave toolbox was used to investigate protoacoustic pressurization, propagation and reconstruction in 2D. To address the tissue heterogeneity effect, a number of physical parameters, including mass density (ρ), speed of sound (c), volumetric thermal expansion coefficient (αV), isobaric specific heat capacity (Cp) and attenuation power law prefactor (α0), were empirically converted from CT number. The performance was evaluated using two figures of merit: mean square error (MSE) of pressure profiles and Bragg peak localization error (ΔBP). The impact of six parameters of the TR inversion was examined, including number of sensors, sampling duration, sampling timestep, spill time, noise level and number of iterations. Results The quantitative accuracy of TR reconstruction and its dependency on the selected parameters is presented. Under optimum conditions, the positioning accuracy of the Bragg peak can be controlled below 1 mm. For instance, MSE is 0.0123 and ΔBP is 0.59 mm under the following conditions (32 sensors, sampling duration: 600 µs, sampling timestep: 40 ns, spill time: 1 µs, no noise). Conclusions The feasibility of TR‐based protoacoustic reconstruction in 2D for proton range verification was first demonstrated. The approach is not only applicable to pencil beam, but also has potential to be extended to passive scattering systems.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simulation studies of time reversal‐based protoacoustic reconstruction for range and dose verification in proton therapy

Yu¹,

Li²,

Zhang³

et al. 2019

Medical Physics

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“…[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Based on the difference between their characteristic proton spills, the protoacoustic pressure amplitude generated by single-bunch synchrotron spills (<1 µs) is expected to be higher than those generated by either clinical cyclotrons, which typically deliver proton spills with ∼50 µs rise and fall times, or clinical synchrotrons, which typically deliver with ∼200 µs rise and fall times. 22 Given the short (<1 µs) spill times and high (up to 100 mA instantaneous 11 ) proton current capabilities, previous observations of the protoacoustic signal have employed linear accelerator, 6 synchrotron, [7][8][9][10][11][12][13][14][15][16][17] and tandem-accelerator 18 proton sources. Protoacoustic signals have also been observed using cyclotron-derived proton beams, 6,19 but these have used custom, modifiable beam lines originally built for research before they were applied to clinical therapy use, and the spill rise times were not reported.…”

Section: Introductionmentioning

confidence: 99%

“…Previous protoacoustic measurements have utilized proton sources at dedicated facilities. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Based on the difference between their characteristic proton spills, the protoacoustic pressure amplitude generated by single-bunch synchrotron spills (<1 µs) is expected to be higher than those generated by either clinical cyclotrons, which typically deliver proton spills with ∼50 µs rise and fall times, or clinical synchrotrons, which typically deliver with ∼200 µs rise and fall times. 22 Given the short (<1 µs) spill times and high (up to 100 mA instantaneous 11 ) proton current capabilities, previous observations of the protoacoustic signal have employed linear accelerator, 6 synchrotron, 7-17 and tandem-accelerator 18 proton sources.…”

Section: Introductionmentioning

confidence: 99%

Experimental observation of acoustic emissions generated by a pulsed proton beam from a hospital‐based clinical cyclotron

et al. 2015

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Purpose: To measure the acoustic signal generated by a pulsed proton spill from a hospital-based clinical cyclotron. Methods: An electronic function generator modulated the IBA C230 isochronous cyclotron to create a pulsed proton beam. The acoustic emissions generated by the proton beam were measured in water using a hydrophone. The acoustic measurements were repeated with increasing proton current and increasing distance between detector and beam. Results: The cyclotron generated proton spills with rise times of 18 µs and a maximum measured instantaneous proton current of 790 nA. Acoustic emissions generated by the proton energy deposition were measured to be on the order of mPa. The origin of the acoustic wave was identified as the proton beam based on the correlation between acoustic emission arrival time and distance between the hydrophone and proton beam. The acoustic frequency spectrum peaked at 10 kHz, and the acoustic pressure amplitude increased monotonically with increasing proton current. Conclusions: The authors report the first observation of acoustic emissions generated by a proton beam from a hospital-based clinical cyclotron. When modulated by an electronic function generator, the cyclotron is capable of creating proton spills with fast rise times (18 µs) and high instantaneous currents (790 nA). Measurements of the proton-generated acoustic emissions in a clinical setting may provide a method for in vivo proton range verification and patient monitoring. C 2015 American Association of Physicists in Medicine. [http://dx

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“…Only in 1988 it was shown that proton beams interacting with water and soft tissue could be detected by using the iono-acoustic effect. [2] Seven years later, in 1995, the real clinical breakthrough took place when Hayakawa demonstrated the detection of acoustic waves in vivo during proton therapy treatment of a hepatic patient. [3] In those days, it was already recognized that for a successful clinical application it is essential to measure the dose distribution in 3-D.…”

Section: Introductionmentioning

confidence: 99%

Modelling the Iono-Acoustic Wave Field for Proton Beam Range Verification

Dongen

Blécourt

Lens

et al. 2018

2018 IEEE International Ultrasonics Symposium (IUS)

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In proton therapy, cancer patients are irradiated with high energy protons. For a successful treatment it is important that the location with the highest energy deposition, the so-called Bragg-peak, is located inside the tumor and not in the healthy surrounding tissue. Here, we investigate if the iono-acoustic wave field generated by the protons can be used to monitor the Bragg-peak location during treatment. To this end we present a new numerical method to model the pressure field generated by a clinical proton pencil beam. To compute the field, we convolve a 3-D Greens function, representing the impulse response of the medium, with a volume density of injection rate source. This source describes the expansion of the medium due to a local temperature increase caused by the energy deposited by the protons. To image the proton dose distribution, we first measure the pressure field synthetically by a matrix transducer positioned below the Bragg peak in a plane parallel to the beam. Next, we use these measurements to solve the linear inverse problem iteratively. To regularize the inversion, we take the temporal behavior of the dose deposition as prior knowledge. For the presented example, where the pencil beam has a proton range of 63 mm we are able to reconstruct the location of the Bragg peak within 4 mm accuracy.

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Acoustic pulse generation in excised muscle by pulsed proton beam irradiation and the possibility of clinical application to radiation therapy.

Abstract: Acoustic pulse generationin excised muscle by pulsed proton beam irradiation and the possibility of clinical application to radiation therapy

Cited by 14 publications

References 4 publications

Simulation studies of time reversal‐based protoacoustic reconstruction for range and dose verification in proton therapy

Simulation studies of time reversal‐based protoacoustic reconstruction for range and dose verification in proton therapy

Experimental observation of acoustic emissions generated by a pulsed proton beam from a hospital‐based clinical cyclotron

Modelling the Iono-Acoustic Wave Field for Proton Beam Range Verification

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