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Tesfamicael B, Athar B, Bejarano Buele A, Kozlyuk V, Nichiporov D, Watts DA, Arjomandy B. Technical Note: Use of commercial multilayer Faraday cup for offline daily beam range verification at the McLaren Proton Therapy Center. Med Phys 2019; 46:1049-1053. [DOI: 10.1002/mp.13348] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 11/08/2018] [Accepted: 12/03/2018] [Indexed: 11/07/2022] Open
Affiliation(s)
| | - Basit Athar
- Karmanos Cancer Institute McLaren Proton Therapy Center Flint MI USA
| | | | - Valeri Kozlyuk
- Karmanos Cancer Institute McLaren Proton Therapy Center Flint MI USA
| | - Dmitri Nichiporov
- Karmanos Cancer Institute McLaren Proton Therapy Center Flint MI USA
| | | | - Bijan Arjomandy
- Karmanos Cancer Institute McLaren Proton Therapy Center Flint MI USA
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Nichiporov D, Coutinho L, Klyachko AV. Characterization of a GEM-based scintillation detector with He–CF4gas mixture in clinical proton beams. Phys Med Biol 2016; 61:2972-90. [DOI: 10.1088/0031-9155/61/8/2972] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Britten RA, Nazaryan V, Davis LK, Klein SB, Nichiporov D, Mendonca MS, Wolanski M, Nie X, George J, Keppel C. Variations in the RBE for cell killing along the depth-dose profile of a modulated proton therapy beam. Radiat Res 2012; 179:21-8. [PMID: 23148508 DOI: 10.1667/rr2737.1] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Considerable evidence now exists to show that that the relative biological effectiveness (RBE) changes considerably along the proton depth-dose distribution, with progressively higher RBE values at the distal part of the modulated, or spread out Bragg peak (SOBP) and in the distal dose fall-off (DDF). However, the highly variable nature of the existing studies (with regards to cell lines, and to the physical properties and dosimetry of the various proton beams) precludes any consensus regarding the RBE weighting factor at any position in the depth-dose profile. We have thus conducted a systematic study on the variation in RBE for cell killing for two clinical modulated proton beams at Indiana University and have determined the relationship between the RBE and the dose-averaged linear energy transfer (LETd) of the protons at various positions along the depth-dose profiles. Clonogenic assays were performed on human Hep2 laryngeal cancer cells and V79 cells at various positions along the SOBPs of beams with incident energies of 87 and 200 MeV. There was a marked variation in the radiosensitivity of both cell lines along the SOBP depth-dose profile of the 87 MeV proton beam. Using Hep2 cells, the D(0.1) isoeffect dose RBE values (normalized against (60)Co) were 1.46 at the middle of SOBP, 2.1 at the distal end of the SOBP and 2.3 in the DDF. For V79 cells, the D(0.1) isoeffect RBE for the 87 MEV beam were 1.23 for the proximal end of the SOBP: 1.46 for the distal SOBP and 1.78 for the DDF. Similar D(0.1) isoeffect RBE values were found for Hep2 cells irradiated at various positions along the depth-dose profile of the 200 MeV beam. Our experimentally derived RBE values were significantly correlated (P = 0.001) with the mean LETd of the protons at the various depths, which confirmed that proton RBE is highly dependent on LETd. These in vitro data suggest that the RBE of the proton beam at certain depths is greater than 1.1, a value currently used in most treatment planning algorithms. Thus, the potential for increased cell killing and normal tissue damage in the distal regions of the proton SOBP may be greater than originally thought.
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Affiliation(s)
- Richard A Britten
- Department of Radiation Oncology, Eastern Virginia Medical School, Norfolk, Virginia 23507, USA.
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Abstract
PURPOSE To compare clinically relevant dosimetric characteristics of proton therapy fields produced by two uniform scanning systems that have a number of similar hardware components but employ different techniques of beam spreading. METHODS This work compares two technologically distinct systems implementing a method of uniform scanning and layer stacking that has been developed independently at Indiana University (IU) and by Ion Beam Applications, S. A. (IBA). Clinically relevant dosimetric characteristics of fields produced by these systems are studied, such as beam range control, peak-to-entrance ratio (PER), lateral penumbra, field flatness, effective source position, precision of dose delivery at different gantry angles, etc. RESULTS Under comparable conditions, both systems controlled beam range with an accuracy of 0.5 mm and a precision of 0.1 mm. Compared to IBA, the IU system produced pristine peaks with a slightly higher PER (3.23 and 3.45, respectively) and smaller, symmetrical, lateral in-air penumbra of 1 mm compared to about 1.9/2.4 mm in the inplane/crossplane (IP/CP) directions for IBA. Large field flatness results in the IP/CP directions were similar: 3.0/2.4% for IU and 2.9/2.4% for IBA. The IU system featured a longer virtual source-to-isocenter position, which was the same for the IP and CP directions (237 cm), as opposed to 212/192 cm (IP/CP) for IBA. Dose delivery precision at different gantry angles was higher in the IBA system (0.5%) than in the IU system (1%). CONCLUSIONS Each of the two uniform scanning systems considered in this work shows some attractive performance characteristics while having other features that can be further improved. Overall, radiation field characteristics of both systems meet their clinical specifications and show comparable results. Most of the differences observed between the two systems are clinically insignificant.
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Affiliation(s)
- Dmitri Nichiporov
- Indiana University Integrated Science and Accelerator Technology Hall, Bloomington, IN 47408, USA.
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Moskvin V, Cheng C, Anferov V, Nichiporov D, Zhao Q, Takashina M, Parola R, Das I. SU-E-T-491: A FLUKA Monte Carlo Computational Model of a Scanning Proton Beam Therapy Nozzle at IU Proton Therapy Center. Med Phys 2012; 39:3818. [DOI: 10.1118/1.4735580] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Nichiporov D, Klyachko A, Solberg K, Kunkler B, Eads A, Ball M. SU-E-T-206: A Patient Dose Monitor for a Proton Uniform Scanning Gantry. Med Phys 2011. [DOI: 10.1118/1.3612156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Das I, Anferov V, Besemer A, Moskvin V, Nichiporov D. SU-E-T-10: A Computational Model for the Estimation of Biological Dose in a Clinical Proton Beam. Med Phys 2011. [DOI: 10.1118/1.3611960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Das I, Fanelli L, Gautam A, Zhao L, Wolanski M, Nichiporov D, Cheng C. SU-GG-T-336: Effect of Treatment and Beam Parameters on Surface Dose in Proton Beam Therapy. Med Phys 2010. [DOI: 10.1118/1.3468733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Fitzek M, Thornton A, Chang A, Shahnazi K, Sullivan M, Wolanski M, Allgower C, Anferov V, Nichiporov D, Derenchuk V. Introducing New Technology into the Clinic: The First Year of Experience in Proton Therapy with a Uniform Scanning System. Int J Radiat Oncol Biol Phys 2009. [DOI: 10.1016/j.ijrobp.2009.07.1602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Hsi WC, Moyers MF, Nichiporov D, Anferov V, Wolanski M, Allgower CE, Farr JB, Mascia AE, Schreuder AN. Energy spectrum control for modulated proton beams. Med Phys 2009; 36:2297-308. [PMID: 19610318 DOI: 10.1118/1.3132422] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [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
In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to +/-21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than +/-3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies.
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Affiliation(s)
- Wen C Hsi
- Midwest Proton Radiotherapy Institute, Bloomington, Indiana 47408 and University Florida Proton Therapy Institute, Jacksonville, Florida 32206, USA.
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Das I, Nichiporov D, Moskvin V, Shahnazi K, Fanelli L, Fitzek M, Johnstone P. SU-FF-T-328: Dose Perturbation and Range Shift with High-Z Medium in Proton Beam. Med Phys 2009. [DOI: 10.1118/1.3181808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Nichiporov D, Solberg K, Klyachko A, Das I, Zhao Q. SU-FF-T-373: Investigation of Humidity Effects On Beam Monitor Performance in a Proton Clinical Gantry. Med Phys 2009. [DOI: 10.1118/1.3181854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Nichiporov D, Solberg K, Hsi W, Wolanski M, Mascia A, Farr J, Schreuder A. Multichannel detectors for profile measurements in clinical proton fields. Med Phys 2007; 34:2683-90. [PMID: 17821976 DOI: 10.1118/1.2746513] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [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: 11/07/2022] Open
Abstract
Two beam profile measurement detectors have been developed at Indiana University Cyclotron Facility to address the need for a tool to efficiently verify dose distributions created with active methods of clinical proton beam delivery. The multipad ionization chamber (MPIC) has 128 ionization chambers arranged in one plane and is designed to measure lateral profiles in fields up to 38 cm in diameter. The MPIC pads have a 5 mm pitch for fields up to 20 cm in diameter and a 7 mm pitch for larger fields, providing the accuracy of field size determination about 0.5 mm. The multilayer ionization chamber (MLIC) detector contains 122 small-volume ionization chambers stacked at a 1.82 mm step (water-equivalent) for depth-dose profile measurements. The MLIC detector can measure profiles up to 20 cm in depth, and determine the 80% distal dose fall-off with about 0.1 mm precision. Both detectors can be connected to the same set of electronics modules, which comprise the detectors' data acquisition system. The detectors have been tested in clinical proton fields produced with active methods of beam delivery such as uniform scanning and energy stacking. This article describes detector performance tests and discusses their results. The test results indicate that the MPIC and MLIC detectors can be used for dosimetric characterization of clinical proton fields. The detectors offer significant time savings during measurements in actively delivered beams compared with traditional measurements using a water phantom.
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Affiliation(s)
- Dmitri Nichiporov
- Indiana University Cyclotron Facility, 2401 Milo B. Sampson Lane, Bloomington, Indiana 47408, USA.
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Mascia A, Farr J, Hsi W, Allgower C, Nichiporov D. TH-C-M100F-06: Therapeutic Uniform Scanning Proton Beam Development and Characterization: Longitudinal Results. Med Phys 2007. [DOI: 10.1118/1.2761684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Hsi WC, Nichiporov D, Allgower C, Farr J, Mascia A, Schreuder N, Wolanski M. SU-EE-A2-06: Using Multi-Element Detector Arrays for Commissioning Active Wobbling and Energy-Stacking Proton Beams. Med Phys 2007. [DOI: 10.1118/1.2760376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Farr J, Mascia A, Nichiporov D, Hsi W, Allgower C, Schreuder A, Thornton A. TU-FF-A2-04: Preliminary Radiological Characterization of An Active Proton Beam Spreading System for Therapeutic Use. Med Phys 2006. [DOI: 10.1118/1.2241647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Nichiporov D, Luckjashin V, Kostjuchenko V. Measurement of the activity of 11C and 22Na sources using a 4pi-beta-gamma coincidence system. Appl Radiat Isot 2004; 60:703-16. [PMID: 15082050 DOI: 10.1016/j.apradiso.2003.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2003] [Revised: 11/05/2003] [Accepted: 11/05/2003] [Indexed: 11/27/2022]
Abstract
Many radiation applications, including positron emission tomography (PET) studies and activation dosimetry, require the knowledge of the activity of short-lived radionuclide samples, whereas relative measurements may be hampered by the absence of a reference source. Using 11C radionuclide as an example, an analytical model based on a probabilistic approach has been set up to predict the activity of a pure positron emitter measured using the 4pi-beta-gamma coincidence technique. The model has been extended to describe the measurement on a 22Na source used to test the measurement technique. Comparison of the modeled results with the measurements confirms the general validity of the model. The model has also been studied for the effect of the variation of key measurement conditions, such as nominal source activity, detector efficiency, detector background levels, and coincidence resolving time. The 4pi-beta-gamma coincidence technique and the results of modeling allow the activity measurements on 22Na and 11C sources with an estimated relative standard uncertainly on the order of one percent.
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Affiliation(s)
- D Nichiporov
- iThemba Laboratories for Accelerator Based Sciences, Somerset West, South Africa.
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Abstract
Reference ionization chamber dosimetry implemented in a clinical proton beam and based on the ICRU 59 recommendations has been verified with an independent carbon activation method. The 12C(p,pn)11C nuclear reaction was used to measure the beam fluence and entrance dose. A method to transfer from the entrance dose to the dose at the ion chamber calibration position has been developed. Measurements performed in a monochromatic 200 MeV beam show that the ratio of absolute doses measured using the carbon activation and the ion chamber methods is 1.017 +/- 0.03 (type A uncertainty). This result is within the uncertainties of both methods employed, which are estimated at +/- 4.3% (carbon activation) and +/- 2.7% (ion chamber calibration).
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Affiliation(s)
- Dmitri Nichiporov
- Themba Laboratories for Accelerator Based Sciences, PO Box 722, Somerset West 7129, South Africa.
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Abstract
A number of designs have been proposed for ridge filters and range modulators used in proton therapy to modify the beam in order to spread out the Bragg peak. Despite the variety of solutions, no simple design capable of providing large fields and easy variation of the spread out Bragg peak (SOBP) length in a pulsed beam has been developed. We propose a compact ridge filter that can be used in a proton beam of any time structure. It allows the production of depth dose distributions that meet the requirements of therapy dose fields.
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Affiliation(s)
- V Kostjuchenko
- Institute for Theoretical and Experimental Physics, Moscow, Russia
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Nichiporov D, Kostjuchenko V, Puhl JM, Bensen DL, Desrosiers MF, Dick CE, McLaughlin WL, Kojima T, Coursey BM, Zink S. Investigation of applicability of alanine and radiochromic detectors to dosimetry of proton clinical beams. Appl Radiat Isot 1995; 46:1355-62. [PMID: 8563704 DOI: 10.1016/0969-8043(95)00213-w] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cancer therapy studies using proton accelerators are underway in several major medical centers in the U.S., Russia, Japan and elsewhere. To facilitate dosimetry intercomparisons between these laboratories, alanine-based detectors produced at the National Institute of Standards and Technology and commercially available radiochromic films were studied for their possible use as passive transfer dosimeters for clinical proton beams. Evaluation of characteristics of these instruments, including the LET dependence of their response of proton energy, was carried out at the Institute of Theoretical and Experimental Physics. Results of absolute dose measurements were regarded as a preliminary step of dose intercomparison between ITEP and NIST. Measurements made in a number of experiments showed average agreement between the ITEP and NIST dosimetry standards to 2.5%.
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Affiliation(s)
- D Nichiporov
- Ionizing Radiation Division, National Institute of Standards and Technology, Technology Administration, U.S. Department of Commerce, Gaithersburg, MD 20899, USA
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