Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
COMPARISONS OF MEASURED BIOLOGICAL RESPONSE AND PREDICTIONS FROM MICRODOSIMETRIC DATA APPLICABLE TO BRACHYTHERAPY
Autore:
ZELLMER DL; SHADLEY JD; GILLIN MT;
Indirizzi:
MED COLL WISCONSIN,DEPT RADIAT ONCOL MILWAUKEE WI 53226
Titolo Testata:
Radiation protection dosimetry
fascicolo: 1-4, volume: 52, anno: 1994,
pagine: 395 - 403
SICI:
0144-8420(1994)52:1-4<395:COMBRA>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
NO
Recensione:
Indirizzi per estratti:
Citazione:
D.L. Zellmer et al., "COMPARISONS OF MEASURED BIOLOGICAL RESPONSE AND PREDICTIONS FROM MICRODOSIMETRIC DATA APPLICABLE TO BRACHYTHERAPY", Radiation protection dosimetry, 52(1-4), 1994, pp. 395-403

Abstract

The site model of the theory of dual radiation action (TDRA) has comeunder question in recent years and has been replaced by the more general track model. The latter reduces to the former if the proximity function is a uniform distribution of energy transfer points and the probability of interaction between two 'sublesions' to produce a lesion isconstant. The site diameter is usually assumed to be of the order of a few nanometres. This investigation tests if the conditions of the site model can bc met for low LET radiation given a site diameter of 1 mum or more. The linear quadratic response of cells to radiation implies that for low dose and/or low dose rate (if repair is viable) that single hit or linear response becomes the dominant process. Because of repair of 'sublesions', at dose rates in brachytherapy (1-7 Gy.h 1), most cell lines are thought to exhibit linear response and, therefore, potentially offer a test of the TDRA site model if differences in linear energy exist. Single event spectra of Co-60, Cs-137, Ir-192, Yb-169 and I-125 were measured in propane tissue-equivalent (TE) gas at a simulated volume of 1.0 mum in diameter. The y(d)sBAR (and therefore the low dose predicted RBEs) relative to Co-60 are 1.2, 1.5, 1.7 and 2.0 for Cs-137, Ir-192, Yb-169 and I-125, respectively. Ir-192 irradiation was selected as a test of predicted RBE from TDRA and cell survival experiments were performed on plateau phase CHO-K1 (repair proficient) and CHO-xrs-5 (repair deficient) cells at dose rates from 0.12 Gy.h-1 to 4.54 Gy.min-1. The xrs-5 line showed a linear response and no dose rate effect while the Kl line exhibited linearity at and below 0.3 Gy.h-1. The RBEs (ratio of the survival curve slopes) of the K1 cells are consistent with those predicted by the site model of the TDRA.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 18/09/20 alle ore 17:02:43