Direct comparison between protons and alpha-particles of the same LET: I. Irradiation methods and inactivation of asynchronous V79, HeLa and C3H 10T1/2 cells.

A direct comparison was carried out of the biological effectiveness of protons and alpha-particles of the same linear energy transfer (LET) under identical conditions with a variety of in vitro biological systems. Monolayers of mammalian cells were irradiated with accelerated beams of protons (1.2 and 1.4 MeV) and alpha-particles (30 and 35 MeV) corresponding to LETs of 23 and 20 keV microns-1 for each particle type. For V79-4 cells it was observed that the linear term of the dose-response for cell inactivation by protons was significantly greater than that for alpha-particles of the same LET. For HeLa and HeLa S3 cells, also, the linear term appeared to be greater for protons, but this was not observed with more limited data for C3H 10T1/2 cells. The result for V79 cells is in agreement with the report of Belli et al. (1989) who observed that the biological effectiveness of protons rose sharply between 17 and 30 keV microns-1 in strong contrast to alpha-particles which reached a peak effectiveness at greater than 100 keV microns-1. These results place new constraints on the biologically relevant features of the microscopic structure of radiation tracks, and have implications for the mechanistic and practical comparison between radiations.

[1]  G. Moschini,et al.  RBE-LET relationship for the survival of V79 cells irradiated with low energy protons. , 1989, International journal of radiation biology.

[2]  J. Thacker,et al.  Mutation and inactivation of cultured mammalian cells exposed to beams of accelerated heavy ions. II. Chinese hamster V79 cells. , 1979, International journal of radiation biology and related studies in physics, chemistry, and medicine.

[3]  D. Goodhead,et al.  Track structure analysis of ultrasoft X-rays compared to high- and low-LET radiations. , 1989, International journal of radiation biology.

[4]  D. Goodhead,et al.  The Mutagenicity of a Particles from Plutonium-238 , 1982 .

[5]  W. G. Cochran.  The combination of estimates from different experiments. , 1954 .

[6]  Maria Antonella Tabocchini,et al.  Proton irradiation facility for radiobiological studies at a 7 MV Van de Graaff accelerator , 1987 .

[7]  C. Geard,et al.  Inactivation of synchronized Chinese Hamster V79 cells with charged-particle track segments. , 1980, Radiation research.

[8]  D. Goodhead,et al.  A Versatile Plutonium-238 Irradiator for Radiobiological Studies with α-particles , 1991 .

[9]  D. Goodhead,et al.  Inactivation and mutation of cultured mammalian cells by aluminium characteristic ultrasoft X-rays. II. Dose-responses of Chinese hamster and human diploid cells to aluminium X-rays and radiations of different LET. , 1977, International journal of radiation biology and related studies in physics, chemistry, and medicine.

[10]  D. Goodhead,et al.  Thickness measurements on V79-4 cells: a comparison between laser scanning confocal microscopy and electron microscopy. , 1990, International journal of radiation biology.

[11]  S. C. Sharma,et al.  Inactivation of cells by heavy ion bombardment. , 1971, Radiation research.

[12]  E. Blakely,et al.  Heavy-ion effects on mammalian cells: inactivation measurements with different cell lines. , 1985, Radiation research. Supplement.

[13]  D. Goodhead,et al.  Mutation and inactivation of mammalian cells by various ionising radiations , 1977, Nature.

[14]  Dudley T. Goodhead,et al.  1 – Relationship of Microdosimetric Techniques to Applications in Biological Systems , 1987 .

[15]  F. Wilcoxon.  Individual Comparisons by Ranking Methods , 1945 .

[16]  D. Goodhead,et al.  Mutation and inactivation of cultured mammalian cells exposed to beams of accelerated heavy ions. I. Irradiation facilities and methods. , 1979, International journal of radiation biology and related studies in physics, chemistry, and medicine.

[17]  G. W. Barendsen,et al.  RESPONSES OF CULTURED CELLS, TUMOURS, AND NORMAL TISSUES TO RADIATIONS OF DIFFERENT LINEAR ENERGY TRANSFER. , 1968 .

[18]  G. Neary.  IRRADIATION OF SIMPLE BIOLOGICAL SPECIMENS BY CHARGED PARTICLES. , 1970 .

[19]  P. B. Price,et al.  A nuclear-track-recording polymer of unique sensitivity and resolution , 1978 .

[20]  Cornelius A. Tobias,et al.  Heavy-Ion Radiobiology: Cellular Studies , 1984 .

[21]  R. Sievert,et al.  Book Reviews : Recommendations of the International Commission on Radiological Protection (as amended 1959 and revised 1962). I.C.R.P. Publication 6. 70 pp. PERGAMON PRESS. Oxford, London and New York, 1964. £1 5s. 0d. [TB/54] , 1964 .

[22]  F Ianzini,et al.  Direct comparison of biological effectiveness of protons and alpha-particles of the same LET. II. Mutation induction at the HPRT locus in V79 cells. , 1992, International journal of radiation biology.

[23]  D. Harder,et al.  Restricted LET Remains a Good Parameter of Radiation Quality , 1988 .

[24]  J. P. Keene.  The Uses of Cyclotrons in Chemistry, Metallurgy and Biology , 1972 .

[25]  James F. Ziegler,et al.  Helium: Stopping Powers and Ranges in All Elemental Matter , 1977 .

[26]  D. Goodhead,et al.  The effect of 238Pu alpha-particles on the mouse fibroblast cell line C3H 10T1/2: characterization of source and RBE for cell survival. , 1987, International journal of radiation biology and related studies in physics, chemistry, and medicine.

[27]  R. Thomas.  The quality factor in radiation protection , 1987 .

[28]  K. Schmidt,et al.  LET dependence of transient yields in the pulse radiolysis of aqueous systems with deuterons and alpha particles. , 1977, Radiation research.

[29]  D. Goodhead,et al.  Inactivation and mutation of cultured mammalian cells by aluminium characteristic ultrasoft X-rays. I. Properties of aluminium X-rays and preliminary experiments with Chinese hamster cells. , 1977, International journal of radiation biology and related studies in physics, chemistry, and medicine.

[30]  D T Goodhead,et al.  Mutation and inactivation of cultured mammalian cells exposed to beams of accelerated heavy ions. IV. Biophysical interpretation. , 1980, International journal of radiation biology and related studies in physics, chemistry, and medicine.

[31]  P. Todd.  Heavy-ion irradiation of cultured human cells. , 1967, Radiation research. Supplement.

[32]  F Ianzini,et al.  Direct comparison of biological effectiveness of protons and alpha-particles of the same LET. III. Initial yield of DNA double-strand breaks in V79 cells. , 1992, International journal of radiation biology.

[33]  B. Vojnovic,et al.  The irradiation of V79 mammalian cells by protons with energies below 2 MeV. Part I: Experimental arrangement and measurements of cell survival. , 1989, International journal of radiation biology.

[34]  R. Cox,et al.  Mutation and inactivation of cultured mammalian cells exposed to beams of accelerated heavy ions. III. Human diploid fibroblasts. , 1979, International journal of radiation biology and related studies in physics, chemistry, and medicine.

[35]  Joseph F. Janni,et al.  Energy loss, range, path length, time-of-flight, straggling, multiple scattering, and nuclear interaction probability , 1982 .