A MICRODOSIMETRIC-KINETIC MODEL OF CELL-DEATH FROM EXPOSURE TO IONIZING-RADIATION OF ANY LET, WITH EXPERIMENTAL AND CLINICAL-APPLICATIONS

Authors
Citation
Rb. Hawkins, A MICRODOSIMETRIC-KINETIC MODEL OF CELL-DEATH FROM EXPOSURE TO IONIZING-RADIATION OF ANY LET, WITH EXPERIMENTAL AND CLINICAL-APPLICATIONS, International journal of radiation biology, 69(6), 1996, pp. 739-755
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Radiology,Nuclear Medicine & Medical Imaging","Nuclear Sciences & Tecnology
ISSN journal
0955-3002
Volume
69
Issue
6
Year of publication
1996
Pages
739 - 755
Database
ISI
SICI code
0955-3002(1996)69:6<739:AMMOCF>2.0.ZU;2-0
Abstract
A model of mammalian cell death and survival following exposure to ion izing radiation that combines a kinetic description of repair and inju ry processes with a microdosimetric description of radiation energy de position is presented. With reduction of one of the defining kinetic e quations from quadratic to linear form, relations are obtained that de scribe the results of commonly performed variations of the cell surviv al experiment. These include single-dose survival of linear-quadratic form, survival after split-dose treatment and after post-irradiation c hange in culture conditions and survival after exposure to continuousl y administered irradiation at low constant dose-rate. The effect of th e inhomogeneous deposition of radiation energy inherent in exposure to radiation of significantly non-zero LET is included in these relation s which apply to radiation of any LET. The values of the kinetic rate and time constants for repair and the processes that lead to cell deat h postulated in the model, which compose the alpha and beta parameters of the linear-quadratic survival relation, are estimated from cell su rvival experiments and DNA double-strand break measurements from the l iterature. A relation for estimating the daily fractional dose equival ent to continuous irradiation as employed in low dose-rate brachythera py cancer treatment is presented.