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1
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Charity RJ, Wylie J, Wang SM, Webb TB, Brown KW, Cerizza G, Chajecki Z, Elson JM, Estee J, Hoff DEM, Kuvin SA, Lynch WG, Manfredi J, Michel N, McNeel DG, Morfouace P, Nazarewicz W, Pruitt CD, Santamaria C, Sweany S, Smith J, Sobotka LG, Tsang MB, Wuosmaa AH. Strong Evidence for ^{9}N and the Limits of Existence of Atomic Nuclei. Phys Rev Lett 2023; 131:172501. [PMID: 37955509 DOI: 10.1103/physrevlett.131.172501] [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: 11/02/2022] [Revised: 03/16/2023] [Accepted: 09/07/2023] [Indexed: 11/14/2023]
Abstract
The boundaries of the chart of nuclides contain exotic isotopes that possess extreme proton-to-neutron asymmetries. Here we report on strong evidence of ^{9}N, one of the most exotic proton-rich isotopes where more than one half of its constitute nucleons are unbound. With seven protons and two neutrons, this extremely proton-rich system would represent the first-known example of a ground-state five-proton emitter. The invariant-mass spectrum of its decay products can be fit with two peaks whose energies are consistent with the theoretical predictions of an open-quantum-system approach; however, we cannot rule out the possibility that only a single resonancelike peak is present in the spectrum.
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Affiliation(s)
- R J Charity
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - J Wylie
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - S M Wang
- Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Institute of Modern Physics, Fudan University, Shanghai 200433, China
- Shanghai Research Center for Theoretical Nuclear Physics, NSFC and Fudan University, Shanghai 200438, China
| | - T B Webb
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - K W Brown
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - G Cerizza
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - Z Chajecki
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA
| | - J M Elson
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - J Estee
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - D E M Hoff
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - S A Kuvin
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - W G Lynch
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Manfredi
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - N Michel
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - D G McNeel
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - P Morfouace
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - W Nazarewicz
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - C D Pruitt
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - C Santamaria
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Sweany
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Smith
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - L G Sobotka
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - M B Tsang
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - A H Wuosmaa
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
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2
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Anthony AK, Niu CY, Wang RS, Wieske J, Brown KW, Chajecki Z, Lynch WG, Ayyad Y, Barney J, Baumann T, Bazin D, Beceiro-Novo S, Boza J, Chen J, Cook KJ, Cortesi M, Ginter T, Mittig W, Pype A, Smith MK, Soto C, Sumithrarachchi C, Swaim J, Sweany S, Teh FCE, Tsang CY, Tsang MB, Watwood N, Wuosmaa AH. Beam particle identification and tagging of incompletely stripped heavy beams with HEIST. Rev Sci Instrum 2022; 93:013306. [PMID: 35104937 DOI: 10.1063/5.0068180] [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: 08/23/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
A challenge preventing successful inverse kinematics measurements with heavy nuclei that are not fully stripped is identifying and tagging the beam particles. For this purpose, the HEavy ISotope Tagger (HEIST) has been developed. HEIST utilizes two micro-channel plate timing detectors to measure the time-of-flight, a multi-sampling ion chamber to measure energy loss, and a high-purity germanium detector to identify isomer decays and calibrate the isotope identification system. HEIST has successfully identified 198Pb and other nearby nuclei at energies of about 75 MeV/A. In the experiment discussed, a typical cut containing 89% of all 198Pb80+ in the beam had a purity of 86%. We examine the issues of charge state contamination. The observed charge state populations of these ions are presented and, using an adjusted beam energy, are well described by the charge state model GLOBAL.
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Affiliation(s)
- A K Anthony
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Y Niu
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - R S Wang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Wieske
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K W Brown
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Z Chajecki
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA
| | - W G Lynch
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Y Ayyad
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Barney
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - T Baumann
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Bazin
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Beceiro-Novo
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Boza
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA
| | - J Chen
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K J Cook
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Cortesi
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - T Ginter
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - W Mittig
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Pype
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - M K Smith
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Soto
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA
| | - C Sumithrarachchi
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Swaim
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA
| | - S Sweany
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - F C E Teh
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Y Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - M B Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - N Watwood
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A H Wuosmaa
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
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3
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Jin Y, Niu CY, Brown KW, Li ZH, Hua H, Anthony AK, Barney J, Charity RJ, Crosby J, Dell'Aquila D, Elson JM, Estee J, Ghazali M, Jhang G, Li JG, Lynch WG, Michel N, Sobotka LG, Sweany S, Teh FCE, Thomas A, Tsang CY, Tsang MB, Wang SM, Wu HY, Yuan CX, Zhu K. First Observation of the Four-Proton Unbound Nucleus ^{18}Mg. Phys Rev Lett 2021; 127:262502. [PMID: 35029460 DOI: 10.1103/physrevlett.127.262502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/18/2021] [Accepted: 11/16/2021] [Indexed: 06/14/2023]
Abstract
^{18}Mg was observed, for the first time, by the invariant-mass reconstruction of ^{14}O+4p events. The ground-state decay energy and width are E_{T}=4.865(34) MeV and Γ=115(100) keV, respectively. The observed momentum correlations between the five particles are consistent with two sequential steps of prompt 2p decay passing through the ground state of ^{16}Ne. The invariant-mass spectrum also provides evidence for an excited state at an excitation energy of 1.84(14) MeV, which is likely the first excited 2^{+} state. As this energy exceeds that for the 2^{+} state in ^{20}Mg, this observation provides an argument for the demise of the N=8 shell closure in nuclei far from stability. However, in open systems this classical argument for shell strength is compromised by Thomas-Ehrman shifts.
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Affiliation(s)
- Y Jin
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - C Y Niu
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K W Brown
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Z H Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - H Hua
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - A K Anthony
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Barney
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - R J Charity
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - J Crosby
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Dell'Aquila
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J M Elson
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - J Estee
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Ghazali
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - G Jhang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J G Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - W G Lynch
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - N Michel
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - L G Sobotka
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - S Sweany
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - F C E Teh
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Thomas
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - C Y Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M B Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - S M Wang
- Institute of Modern Physics, Fudan University, Shanghai 200433, China
- FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - H Y Wu
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - C X Yuan
- Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082, China
| | - K Zhu
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
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4
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Charity RJ, Webb TB, Elson JM, Hoff DEM, Pruitt CD, Sobotka LG, Brown KW, Cerizza G, Estee J, Lynch WG, Manfredi J, Morfouace P, Santamaria C, Sweany S, Tsang CY, Tsang MB, Zhang Y, Zhu K, Kuvin SA, McNeel D, Smith J, Wuosmaa AH, Chajecki Z. Observation of the Exotic Isotope ^{13}F Located Four Neutrons beyond the Proton Drip Line. Phys Rev Lett 2021; 126:132501. [PMID: 33861136 DOI: 10.1103/physrevlett.126.132501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/22/2021] [Accepted: 02/24/2021] [Indexed: 06/12/2023]
Abstract
A ^{13}F resonance was observed following a charge-exchange reaction between a fast ^{13}O beam and a ^{9}Be target. The resonance was found in the invariant-mass distribution of 3p+^{10}C events and probably corresponds to a 5/2^{+} excited state. The ground state was also expected to be populated, but was not resolved from the background. The observed level decays via initial proton emissions to both the ground and first 2^{+} state of ^{12}O, which subsequently undergo 2p decay. In addition, there may also be a significant proton decay branch to the second 2^{+} level in ^{12}O. The wave function associated with the observed level may be collectivized due to coupling to the continuum as is it located just above the threshold for proton decay to the 2_{2}^{+} state of ^{12}O.
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Affiliation(s)
- R J Charity
- Departments of Chemistry and Physics, Washington University, St. Louis, Missouri 63130, USA
| | - T B Webb
- Departments of Chemistry and Physics, Washington University, St. Louis, Missouri 63130, USA
| | - J M Elson
- Departments of Chemistry and Physics, Washington University, St. Louis, Missouri 63130, USA
| | - D E M Hoff
- Departments of Chemistry and Physics, Washington University, St. Louis, Missouri 63130, USA
| | - C D Pruitt
- Departments of Chemistry and Physics, Washington University, St. Louis, Missouri 63130, USA
| | - L G Sobotka
- Departments of Chemistry and Physics, Washington University, St. Louis, Missouri 63130, USA
| | - K W Brown
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - G Cerizza
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Estee
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - W G Lynch
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Manfredi
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - P Morfouace
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Santamaria
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - S Sweany
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Y Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - M B Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Y Zhang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Zhu
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - S A Kuvin
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - D McNeel
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - J Smith
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - A H Wuosmaa
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - Z Chajecki
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA
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5
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Webb TB, Wang SM, Brown KW, Charity RJ, Elson JM, Barney J, Cerizza G, Chajecki Z, Estee J, Hoff DEM, Kuvin SA, Lynch WG, Manfredi J, McNeel D, Morfouace P, Nazarewicz W, Pruitt CD, Santamaria C, Smith J, Sobotka LG, Sweany S, Tsang CY, Tsang MB, Wuosmaa AH, Zhang Y, Zhu K. First Observation of Unbound ^{11}O, the Mirror of the Halo Nucleus ^{11}Li. Phys Rev Lett 2019; 122:122501. [PMID: 30978039 DOI: 10.1103/physrevlett.122.122501] [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: 12/20/2018] [Revised: 02/23/2019] [Indexed: 06/09/2023]
Abstract
The structure of the extremely proton-rich nucleus _{8}^{11}O_{3}, the mirror of the two-neutron halo nucleus _{3}^{11}Li_{8}, has been studied experimentally for the first time. Following two-neutron knockout reactions with a ^{13}O beam, the ^{11}O decay products were detected after two-proton emission and used to construct an invariant-mass spectrum. A broad peak of width ∼3.4 MeV was observed. Within the Gamow coupled-channel approach, it was concluded that this peak is a multiplet with contributions from the four lowest ^{11}O resonant states: J^{π}=3/2_{1}^{-}, 3/2_{2}^{-}, 5/2_{1}^{+}, and 5/2_{2}^{+}. The widths and configurations of these states show strong, nonmonotonic dependencies on the depth of the p-^{9}C potential. This unusual behavior is due to the presence of a broad threshold resonant state in ^{10}N, which is an analog of the virtual state in ^{10}Li in the presence of the Coulomb potential. After optimizing the model to the data, only a moderate isospin asymmetry between ground states of ^{11}O and ^{11}Li was found.
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Affiliation(s)
- T B Webb
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
| | - S M Wang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K W Brown
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - R J Charity
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - J M Elson
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - J Barney
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - G Cerizza
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Z Chajecki
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, USA
| | - J Estee
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - D E M Hoff
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - S A Kuvin
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - W G Lynch
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Manfredi
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - D McNeel
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - P Morfouace
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - W Nazarewicz
- Department of Physics and Astronomy and FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C D Pruitt
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - C Santamaria
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Smith
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - L G Sobotka
- Department of Physics, Washington University, St. Louis, Missouri 63130, USA
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, USA
| | - S Sweany
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Y Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - M B Tsang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A H Wuosmaa
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - Y Zhang
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Zhu
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
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6
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Affiliation(s)
- J. Romanos
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA
- Department of Natural Sciences, Lebanese American University, Byblos, Lebanon
| | - S. Sweany
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA
| | - T. Rash
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA
| | - L. Firlej
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA
- LCVN, Université Montpellier 2, 34095 Montpellier Cedex 5, France
| | - B. Kuchta
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA
- Laboratoire MARIDEL, Aix-Marseille Université, 13396 Marseille, France
| | - J.C. Idrobo
- Advanced Microscopy Laboratory, Oak Ridge National Lab, Oak Ridge, TN 37831, USA
| | - P. Pfeifer
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA
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7
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Abstract
Purpose: Melatonin has neuroprotective effects in animal studies and has been suggested to decrease adverse reactions of chemotherapy including neuropathy. This pilot trial aimed at assessing whether melatonin, given during taxane chemotherapy for breast cancer, will decrease the incidence and/or severity of neuropathy. Methods: Twenty two consecutive patients beginning chemotherapy for breast cancer with paclitaxel, or docetaxel were enrolled. Patients received melatonin 21 mg daily at bedtime. Incidence and severity of neuropathy were assessed using neurological examinations, toxicity assessment per NCI-CTC 3.0 scale and FACT-Taxane quality of life questionnaire. Results: Neuropathy was seen in 45% (n = 10) of patients, 23% (n = 6) grade 1 and 22% (n = 5) Grade 2 neuropathy. No grade 3 neuropathies were reported. The majority (55%) of all patients reported no neuropathy. Compliance with melatonin (>60% of dose) was seen in most patients (86%) No patient reported daytime sedation. The median FACT-Taxane quality of life end of study score was 137, with only a 0.5 median decline from baseline. Conclusion: Patients receiving melatonin during taxane chemotherapy had a reduced incidence of neuropathy. Melatonin may be useful in the prevention or reduction of taxane-induced neuropathy and in maintaining quality of life. Larger trials are warranted to further explore the role of melatonin in neuropathy treatment and prevention.
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Affiliation(s)
- Z Nahleh
- Karmanos Cancer Institute, Division of Hematology-Oncology, Wayne State University 4100 John R, 4HWCRC, Detroit, MI 48201, USA
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Sweany S, Lafollette J, Pruemer J, Swango M, Clark M, Wainino A, Nahleh Z. Effect of melatonin on taxane-induced neuropathy in breast cancer patients. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.19640] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
19640 Background: Neurotoxicity caused by taxane chemotherapies(CT) can be dose limiting and can cause a decrease in quality of life. Melatonin has been evaluated for its use in decreasing adverse reactions of CT. Preclinical data suggests that melatonin has neuroprotective capability. The objective of this study is to determine if melatonin will decrease the incidence and severity of taxane-related neuropathy. Methods: Fifty patients beginning CT for any stage of breast cancer with paclitaxel, albumin-bound paclitaxel, or docetaxel will be enrolled. Patients should have no underlying neuropathy. Melatonin is given at 21 mg at bedtime on Day 1 and continued for 28 days after the last taxane dose. Every 28 days, neuropathy is assessed using the NCI-CTC 3.0 scale and possible side effects of melatonin are evaluated. Quality of life (QOL) is analyzed using the FACT-Taxane QOL assessment. Outcomes analyzed included the incidence and severity of neuropathy, and changes in QOL. Results: Currently 17 patients have been enrolled with 12 having completed taxaneCT and melatonin. Five have withdrawn due to non-medical reasons and were evaluated for toxicities. The mean age is 49 years (range 36–67 years). The end of study FACT-Taxane score was available for 11 of the 12 patients, with an average score of 135 (range 106–168). The average baseline QOL score was 131 (range 99–148). The average change in QOL score was +4. Eleven have completed paclitaxel with an average dose of 862 mg/m2 (range 525–1620 mg/m2). One patient received docetaxel t 450 mg/m2. Five patients self- reported adverse effects including night-time sedation (2), hot flashes (1), headache (1), constipation (1), nail darkening (1), and fatigue (1). Neuropathy distribution was as follows : 50 % (6) of patients had grade 0, 33% (4) grade 1, and 16% (2) grade 2 neuropathy. The mean change in neuropathy score was +0.67. Conclusion: Melatonin appears promising as a neuroprotective agent in patients receiving taxane-based chemotherapy. No patient developed grade 3 or 4 neuropathy compared to historical controls of 22–33%. Fifty percent of patients treated with melatonin while on taxane CT developed no neuropathy, and those who did, had grade 1 or 2 neuropathy.QOL was maintained. Melatonin's neuroprotective effect should be further evaluated. No significant financial relationships to disclose.
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Affiliation(s)
- S. Sweany
- University of Cincinnati, Cincinnati, OH
| | | | - J. Pruemer
- University of Cincinnati, Cincinnati, OH
| | - M. Swango
- University of Cincinnati, Cincinnati, OH
| | - M. Clark
- University of Cincinnati, Cincinnati, OH
| | - A. Wainino
- University of Cincinnati, Cincinnati, OH
| | - Z. Nahleh
- University of Cincinnati, Cincinnati, OH
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