Acoustic signals from proton beam interaction in water—Comparing experimental data and Monte Carlo simulation

Feasibility of RACT for 3D dose measurement and range verification in a water phantom

“…Both approaches are predicated on the formation of radioisotopes and excited nuclei resulting from the inelastic collisions of protons with the endogenous constituents within tissue. For example, the production of the positron emitters 11 C, 14 N, and 15 O results in annihilation and production of two 0.511 MeV gamma quanta used to form PET images, [1][2][3] while the emission of high energy gammas (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) accompanying the decay of the excited nuclear states of 12 C, 16 O, and 40 Ca (Ref. 4) forms the basis of SPECT.…”

“…Past studies have demonstrated a relationship between the pressure signals as measured by a transducer and hydrophone from a pulsed proton beam over a range of energies. [6][7][8] However, the combined work of De Bonis et al and Sulak et al demonstrates a discrepancy that could be explained based on the geometry of the ultrasound detector and proton beam properties. To overcome these problems and provide a clinically viable diagnostic method of 3D dosimetric imaging, the ultrasound source formed after a brief increase in temperature from a pulse proton beam can be localized by acquiring these pressure signals over many projections and forming an image using thermoacoustic computed tomographic methods.…”

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

“…In addition to the aforementioned approaches, in vivo range/dose verification utilizing proton‐induced acoustic (protoacoustic) signals is a very promising alternative solution. Since the concept was initially proposed by Askaryan, many groups have worked on a number of aspects including both numerical simulations and experimental measurements . Sulak et al experimentally detected acoustic signals produced by proton beams in fluid media and successfully demonstrated a thermal expansion model for this phenomenon .…”

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

“…[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.…”

“…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.…”