title: Relative biological effectiveness of simulated solar particle event proton radiation to induce acute hematological change in the porcine model.
abstract: The present study was undertaken to determine relative biological effectiveness (RBE) values for simulated solar particle event (SPE) radiation on peripheral blood cells using Yucatan minipigs and electron-simulated SPE as the reference radiation. The results demonstrated a generally downward trend in the RBE values with increasing doses of simulated SPE radiation for leukocytes in the irradiated animals. The fitted RBE values for white blood cells (WBCs), lymphocytes, neutrophils, monocytes and eosinophils were above 1.0 in all three radiation dose groups at all time-points evaluated, and the lower limits of the 95% confidence intervals were > 1.0 in the majority of the dose groups at different time-points, which together suggest that proton-simulated SPE radiation is more effective than electron-simulated SPE radiation in reducing the number of peripheral WBCs, lymphocytes, neutrophils, monocytes and eosinophils, especially at the low end of the 5-10 Gy dose range evaluated. Other than the RBE values, the responses of leukocytes to electron-simulated SPE radiation and proton-simulated SPE radiation exposure are highly similar with respect to the time-course, the most radiosensitive cell type (the lymphocytes), and the shape of the dose-response curves, which is generally log-linear. These findings provide additional evidence that electron-simulated SPE radiation is an appropriate reference radiation for determination of RBE values for the simulated SPE radiations, and the RBE estimations using electron-simulated SPE radiation as the reference radiation are not complicated by other characteristics of the leukocyte response to radiation exposure.
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, 195 John Morgan Building, 3620 Hamilton Walk, Philadelphia, PA 19104-6072, USA.
authors.forename: Jenine K
authors.initials: JK
authors.lastname: Sanzari
authors.forename: Steven X
authors.initials: SX
authors.lastname: Wan
authors.forename: Eric S
authors.initials: ES
authors.lastname: Diffenderfer
authors.forename: Keith A
authors.initials: KA
authors.lastname: Cengel
authors.forename: Ann R
authors.initials: AR
authors.lastname: Kennedy
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004307:Dose-Response Relationship, Radiation; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects*; D011522:Protons; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000502:physiology*; D012062:Relative Biological Effectiveness; D012993:Solar Energy; D013552:Swine; D013556:Swine, Miniature
chemical_list: D011522:Protons
keywords: blood cells; protons; relative biological effectiveness; solar particle event
references.citation: Radiat Res. 2013 Jul;180(1):7-16
references.pmid: 23672458
references.citation: Radiother Oncol. 1988 Jan;11(1):73-82
references.pmid: 3344355
references.citation: Naturwissenschaften. 2007 Jul;94(7):517-26
references.pmid: 17235598
references.citation: Radiat Environ Biophys. 2010 Nov;49(4):715-21
references.pmid: 20725839
references.citation: Nucl Instrum Methods Phys Res A. 2000 Apr 1;443(2-3):254-63
references.pmid: 11543201
references.citation: In Vivo. 2008 Mar-Apr;22(2):159-69
references.pmid: 18468399
references.citation: Radiat Res. 1986 Jan;105(1):58-67
references.pmid: 3080801
references.citation: Arch Pathol. 1975 Feb;99(2):105-10
references.pmid: 1115680
references.citation: Radiat Meas. 1999 Jun;30(3):361-82
references.pmid: 11543148
references.citation: Phys Med Biol. 2002 Apr 21;47(8):1303-19
references.pmid: 12030557
references.citation: Health Phys. 2009 Apr;96(4):465-76
references.pmid: 19276707
references.citation: Radiat Meas. 1999 Jun;30(3):337-43
references.pmid: 11543140
references.citation: Acta Astronaut. 2005 May-Jun;56(9-12):969-74
references.pmid: 15835055
references.citation: Adv Space Res. 2003;32(1):109-14
references.pmid: 14727670
references.citation: Int J Radiat Oncol Biol Phys. 1995 Mar 30;31(5):1319-39
references.pmid: 7713791
references.citation: J Radiat Res. 1976 Sep;17(3):135-41
references.pmid: 824446
references.citation: Acta Oncol. 1997;36(6):637-42
references.pmid: 9408156
references.citation: Phys Med Biol. 2005 Jun 21;50(12):2765-77
references.pmid: 15930601
references.citation: Technol Cancer Res Treat. 2006 Apr;5(2):81-9
references.pmid: 16551128
references.citation: Int J Radiat Oncol Biol Phys. 2002 Jun 1;53(2):407-21
references.pmid: 12023146