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Farr JB, Mascia AE, Hsi WC, Allgower CE, Jesseph F, Schreuder AN, Wolanski M, Nichiporov DF, Anferov V. Clinical characterization of a proton beam continuous uniform scanning system with dose layer stacking. Med Phys 2009; 35:4945-54. [PMID: 19070228 DOI: 10.1118/1.2982248] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A proton beam delivery system on a gantry with continuous uniform scanning and dose layer stacking at the Midwest Proton Radiotherapy Institute has been commissioned and accepted for clinical use. This paper was motivated by a lack of guidance on the testing and characterization for clinical uniform scanning systems. As such, it describes how these tasks were performed with a uniform scanning beam delivery system. This paper reports the methods used and important dosimetric characteristics of radiation fields produced by the system. The commissioning data include the transverse and longitudinal dose distributions, penumbra, and absolute dose values. Using a 208 MeV cyclotron's proton beam, the system provides field sizes up to 20 and 30 cm in diameter for proton ranges in water up to 27 and 20 cm, respectively. The dose layer stacking method allows for the flexible construction of spread-out Bragg peaks with uniform modulation of up to 15 cm in water, at typical dose rates of 1-3 Gy/min. For measuring relative dose distributions, multielement ion chamber arrays, small-volume ion chambers, and radiographic films were employed. Measurements during the clinical commissioning of the system have shown that the lateral and longitudinal dose uniformity of 2.5% or better can be achieved for all clinically important field sizes and ranges. The measured transverse penumbra widths offer a slight improvement in comparison to those achieved with a double scattering beam spreading technique at the facility. Absolute dose measurements were done using calibrated ion chambers, thermoluminescent and alanine detectors. Dose intercomparisons conducted using various types of detectors traceable to a national standards laboratory indicate that the measured dosimetry data agree with each other within 5%.
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Affiliation(s)
- J B Farr
- Indiana University, Department of Physics, Swain Hall West, Room 117, 727 E. Third St., Bloomington, Indiana 47405, USA.
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Allgower CE, Schreuder AN, Farr JB, Mascia AE. Experiences with an application of industrial robotics for accurate patient positioning in proton radiotherapy. Int J Med Robot 2007; 3:72-81. [PMID: 17441029 DOI: 10.1002/rcs.128] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Protons beams deliver targeted radiation doses with greater precision than is possible with electrons or megavoltage X-ray photons, but to retain this advantage, patient positioning systems at proton clinics must meet tighter accuracy requirements. For this and other reasons, robots were incorporated into the treatment room systems at MPRI. METHODS The Midwest Proton Radiotherapy Institute (MPRI) is the first radiotherapy facility in the United States to use commercial robots with six degrees of freedom for patient positioning, rather than a traditional bed with four degrees of freedom. RESULTS This paper outlines the ways in which robots are used at MPRI and attempts to distil insights from the experience of treating over 200 radiotherapy patients with a robotic system from February 2004 to late 2006. CONCLUSIONS The system has performed well, and with great reliability, but there is room for future improvement, especially in ease of use and in reducing the time to get patients into position.
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Affiliation(s)
- C E Allgower
- Medical Physics Department, Midwest Proton Radiotherapy Institute, Bloomington, IN 47408, USA.
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Nefkens BMK, Prakhov S, Gårdestig A, Allgower CE, Bekrenev V, Briscoe WJ, Clajus M, Comfort JR, Craig K, Grosnick D, Isenhower D, Knecht N, Koetke D, Koulbardis A, Kozlenko N, Kruglov S, Lolos G, Lopatin I, Manley DM, Manweiler R, Marusić A, McDonald S, Olmsted J, Papandreou Z, Peaslee D, Phaisangittisakul N, Price JW, Ramirez AF, Sadler M, Shafi A, Spinka H, Stanislaus TDS, Starostin A, Staudenmaier HM, Supek I, Tippens WB. Test of charge conjugation invariance. Phys Rev Lett 2005; 94:041601. [PMID: 15783546 DOI: 10.1103/physrevlett.94.041601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Indexed: 05/24/2023]
Abstract
We report on the first determination of upper limits on the branching ratio (BR) of eta decay to pi0pi0gamma and to pi0pi0pi0gamma. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(eta-->pi0pi0gamma)<5 x 10(-4) at the 90% confidence level, in support of C invariance of isoscalar electromagnetic interactions of the light quarks. We have also measured BR(eta-->pi0pi0pi0gamma)<6 x 10(-5) at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions.
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Affiliation(s)
- B M K Nefkens
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
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Stephenson EJ, Bacher AD, Allgower CE, Gårdestig A, Lavelle CM, Miller GA, Nann H, Olmsted J, Pancella PV, Pickar MA, Rapaport J, Rinckel T, Smith A, Spinka HM, van Kolck U. Observation of the charge symmetry breaking d+d-->4He+pi(0) reaction near threshold. Phys Rev Lett 2003; 91:142302. [PMID: 14611518 DOI: 10.1103/physrevlett.91.142302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2003] [Indexed: 05/24/2023]
Abstract
We report the first observation of the charge symmetry breaking d+d-->4He+pi(0) reaction near threshold. Measurements using a magnetic channel (gated by two photons) of the 4He scattering angle and momentum (from time of flight) permitted reconstruction of the pi(0) "missing mass," the quantity used to separate 4He+pi(0) events from the continuum of double radiative capture 4He+gamma+gamma events. We measured total cross sections for neutral pion production of 12.7+/-2.2 pb at 228.5 MeV and 15.1+/-3.1 pb at 231.8 MeV. The uncertainty is dominated by statistical errors. These cross sections arise fundamentally from the down-up quark mass difference and quark electromagnetic effects that contribute in part through meson mixing (e.g., pi(0)-eta) mechanisms.
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Affiliation(s)
- E J Stephenson
- Indiana University Cyclotron Facility, Bloomington, Indiana 47408, USA
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Craig K, Comfort JR, Allgower CE, Bekrenev V, Berger E, Briscoe WJ, Clajus M, Draper B, Grosnick D, Isenhower D, Knecht N, Koetke D, Koulbardis A, Kozlenko N, Kruglov S, Lolos GJ, Lopatin I, Manley DM, Manweiler R, Marusić A, McDonald S, Nefkens BMK, Olmsted J, Papandreou Z, Peaslee D, Phaisangittisakul N, Prakhov S, Price JW, Pulver M, Ramirez AF, Sadler ME, Shafi A, Spinka H, Stanislaus S, Starostin A, Supek I, Staudenmaier HM, Tippens WB. Dynamics of the pi(-)p-->pi(0)pi(0)n reaction for p(pi(-))<750 MeV/c. Phys Rev Lett 2003; 91:102301. [PMID: 14525473 DOI: 10.1103/physrevlett.91.102301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2003] [Indexed: 05/24/2023]
Abstract
Data are presented for the reaction pi(-)p-->pi(0)pi(0)n in the range from threshold to p(pi(-))=750 MeV/c. The systematics of the data and multipole analyses are examined for sensitivity to a f(0)(600) ("sigma") meson. A one-pion-exchange mechanism is found to be very weak, or absent. The reaction appears to become dominated by sequential pi(0) decays through the Delta(1232) resonance as the beam momentum increases, along with substantial interference effects from several competing mechanisms.
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Affiliation(s)
- K Craig
- Arizona State University, Tempe, Arizona 85287-1504, USA
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Manley DM, Abaev VV, Allgower CE, Bekrenev V, Briscoe WJ, Clajus M, Comfort JR, Craig K, Grosnick D, Isenhower D, Knecht N, Koetke DD, Kulbardis AA, Kozlenko NG, Kruglov S, Lolos G, Lopatin IV, Manweiler R, Marusić A, McDonald S, Nefkens BMK, Olmsted J, Papandreou Z, Peaslee DC, Phaisangittisakul N, Prakhov S, Price JW, Ramirez AF, Sadler M, Shafi A, Spinka H, Stanislaus TDS, Starostin A, Staudenmaier HM, Strakovsky II, Supek I, Tippens WB. Properties of the Lambda(1670)(1-)/2 resonance. Phys Rev Lett 2002; 88:012002. [PMID: 11800936 DOI: 10.1103/physrevlett.88.012002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2001] [Indexed: 05/23/2023]
Abstract
Recently the Crystal Ball Collaboration measured precise new data for the near-threshold reaction K(-)p-->etaLambda, which is dominated by formation of the Lambda(1670)1 / 2(-). In this Letter, we present results of a unitary, multichannel analysis that incorporates the new Crystal Ball data. For our preferred fit, we obtain mass M = 1673+/-2 MeV, width Gamma = 23+/-6 MeV, and elasticity x = 0.37+/-0.07. This elasticity is significantly larger than previously recognized. Resonance parameters of our preferred fit are in striking agreement with the quark-model predictions of Koniuk and Isgur.
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Affiliation(s)
- D M Manley
- Kent State University, Kent, Ohio 44242-0001, USA
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Tippens WB, Prakhov S, Allgower CE, Bekrenev V, Berger E, Briscoe WJ, Clajus M, Comfort JR, Craig K, Efendiev A, Grosnick D, Holstein BR, Huber GM, Isenhower D, Knecht N, Koetke D, Koulbardis A, Kozlenko N, Kruglov S, Lolos GJ, Lopatin I, Manley DM, Marusić A, Manweiler R, McDonald S, Nefkens BM, Olmsted J, Papandreou Z, Phaisangittisakul N, Price JW, Pulver M, Ramirez AF, Sadler ME, Shafi A, Spinka H, Stanislaus S, Starostin A, Staudenmaier HM. Determination of the quadratic slope parameter in eta-->3pi(0) decay. Phys Rev Lett 2001; 87:192001. [PMID: 11690403 DOI: 10.1103/physrevlett.87.192001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2001] [Indexed: 05/23/2023]
Abstract
We have determined the quadratic slope parameter alpha for eta-->3pi(0) to be alpha = -0.031(4) from a 99% pure sample of 10(6)eta-->3pi(0) decays produced in the reaction pi(-)p-->n(eta) close to the eta threshold using the Crystal Ball detector at the AGS. The result is four times more precise than the present world data and disagrees with current chiral perturbation theory calculations by about four standard deviations.
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Affiliation(s)
- W B Tippens
- University of California, Los Angeles, Los Angeles, California 90095-1547
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Starostin A, Staudenmaier HM, Allgower CE, Bekrenev V, Berger E, Briscoe WJ, Clajus M, Comfort JR, Craig K, Grosnick D, Isenhower D, Knecht N, Koetke D, Koulbardis A, Kozlenko N, Kruglov S, Kycia T, Lolos G, Lopatin I, Manley DM, Manweiler B, Marusić A, McDonald S, Nefkens BM, Olmsted J, Papandreou Z, Peaslee D, Peterson RJ, Phaisangittisakul N, Prakhov S, Pulver M, Ramirez AF, Sadler M, Shafi A, Slaus I, Spinka H, Stanislaus S, Supek I, Tippens WB. Measurement of pi(0)pi(0) production in the nuclear medium by pi(-) interactions at 0.408 GeV/c. Phys Rev Lett 2000; 85:5539-5542. [PMID: 11136041 DOI: 10.1103/physrevlett.85.5539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2000] [Indexed: 05/23/2023]
Abstract
We report on an investigation of the (pi(-),pi(0)pi(0)) reaction by means of measurements of the pi(0)pi(0) invariant mass distributions from pi(-) interactions on H, D, C, Al, and Cu targets at p(pi(-)) = 0.408 GeV/c. The sharp, strong peak in the pi(+)pi(-) invariant mass near 2m(pi) reported by the CHAOS Collaboration is not seen in our pi(0)pi(0) data. However, we do observe a change in the shape of the pi(0)pi(0) invariant mass spectrum for the different targets, indicating that the pi(0)pi(0) interaction diminishes in the nuclear medium as represented by nuclei D, C, Al, and Cu, compared to hydrogen.
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Affiliation(s)
- A Starostin
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
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