M. Belli et al., RBE-LET RELATIONSHIPS FOR CELL INACTIVATION AND MUTATION INDUCED BY LOW-ENERGY PROTONS IN V79 CELLS - FURTHER RESULTS AT THE LNL FACILITY, International journal of radiation biology (Print), 74(4), 1998, pp. 501-509
Citations number
34
Categorie Soggetti
Radiology,Nuclear Medicine & Medical Imaging","Biology Miscellaneous","Nuclear Sciences & Tecnology
Purpose: RBE-LET relationships For cell inactivation and hprt mutation
in V79 cells have been studied with mono-energetic low-energy proton
beams at the radiobiological facility of the INFN-Laboratori Nazionali
di Legnaro (LNL), Padova, Italy. Materials and methods: V79 cells wer
e irradiated in mono-laver on mylar coated stainless steel petri dishe
s, in air. Inactivation data were obtained at 7.7, 34.6 and 37.8 keV/m
u m and hprt mutation was studied at 7.7 and 37.8 keV/mu m. Additional
data were also collected for both the end points with the proton LET
already considered in our previous publications, namely 11.0, 20.0 and
30.5 keV/mu m. Results: A maximum in the RBE-LET relationship for cel
l inactivation was found at around 31 keV/mu m, while the RBE for muta
tion induction increased continuously with LET. Conclusions: The proto
n RBE-LET relationship for cell inactivation is shifted to lower LET v
alues compared with that for heavier ions. For mutation induction, pro
tons of LET equal to 7.7 keV/mu m gave an RBE value comparable with th
at obtained by helium ions of about 20 keV/mu m. Mutagenicity and leth
ality caused by protons at low doses in the LET range 7.7-31 keV/mu m
were proportional, while the data at 37.8 keV/mu m suggest that this m
ay not hold at higher LET values.