Shielding calculations for a 200-MeV proton accelerator and comparisons with experimental data

Alsmiller, R.G.; Santoro, R.T.; Barish, J.

doi:10.2172/4235018

Cited by 3 publications

(2 citation statements)

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“…Currently these simulations have not been benchmarked against experimental measurements, but the neutron production observed agrees with what others reported previously. [31][32][33] …”

Section: Iib Monte Carlo Neutron Production Simulationsmentioning

confidence: 99%

“…34,35 The neutron energy spectra results presented here are similar to what others have reported for a proton beam stopping in a thick water and tissuelike target. [31][32][33] In the present work, the proposed DWA treatment system does not require any passive beam modification devices such as scattering foils, range modulators, or other devices used to deliver the proton beam to the patient. Hence, neutron production occurs principally in the stopping media.…”

Section: Iiib Neutron Productionmentioning

confidence: 99%

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Maximum proton kinetic energy and patient‐generated neutron fluence considerations in proton beam arc delivery radiation therapy

et al. 2009

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Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy of protons, immediately prior to entry into the patient, that must be reached by the treatment system. The commonly used value for the maximum kinetic energy required for a medical proton accelerator is 250 MeV, but it has not been demonstrated that this energy is indeed necessary to treat all or most patients eligible for proton therapy. This article quantifies the maximum kinetic energy of protons, immediately prior to entry into the patient, necessary to treat a given percentage of patients with rotational proton therapy, and examines the impact of this energy threshold on the cost and feasibility of a compact, gantry-mounted proton accelerator treatment system. One hundred randomized treatment plans from patients treated with IMRT were analyzed. The maximum radiological pathlength from the surface of the patient to the distal edge of the treatment volume was obtained for 180°continuous arc proton therapy and for 180°split arc proton therapy ͑two 90°arcs͒ using CT# profiles from the Pinnacle™ ͑Philips Medical Systems, Madison, WI͒ treatment planning system. In each case, the maximum kinetic energy of protons, immediately prior to entry into the patient, that would be necessary to treat the patient was calculated using proton range tables for various media. In addition, Monte Carlo simulations were performed to quantify neutron production in a water phantom representing a patient as a function of the maximum proton kinetic energy achievable by a proton treatment system. Protons with a kinetic energy of 240 MeV, immediately prior to entry into the patient, were needed to treat 100% of patients in this study. However, it was shown that 90% of patients could be treated at 198 MeV, and 95% of patients could be treated at 207 MeV. Decreasing the proton kinetic energy from 250 to 200 MeV decreases the total neutron energy fluence produced by stopping a monoenergetic pencil beam in a water phantom by a factor of 2.3. It is possible to significantly lower the requirements on the maximum kinetic energy of a compact proton accelerator if the ability to treat a small percentage of patients with rotational therapy is sacrificed. This decrease in maximum kinetic energy, along with the corresponding decrease in neutron production, could lower the cost and ease the engineering constraints on a compact proton accelerator treatment facility.

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“…Currently these simulations have not been benchmarked against experimental measurements, but the neutron production observed agrees with what others reported previously. [31][32][33] …”

Section: Iib Monte Carlo Neutron Production Simulationsmentioning

confidence: 99%