Inactivation of human cells exposed to fractionated doses of low energy protons: relationship between cell sensitivity and recovery efficiency.

Within the framework of radiation biophysics research in the hadrontherapy field, split-dose studies have been performed on four human cell lines with different radiation sensitivity (SCC25, HF19, H184B5 F5-1 M10, and SQ20B). Low energy protons of about 8 and 20 keV/micron LET and gamma-rays were used to study the relationship between the recovery ratio and the radiation quality. Each cell line was irradiated with two dose values corresponding to survival levels of about 5% and 1%.

DNA DSB induction and rejoining in V79 cells irradiated with light ions: a constant field gel electrophoresis study.

Purpose: To study the induction and the time-course of rejoining of DNA double strand breaks (DSB) in V79 cells irradiated with light ions with different linear energy transfer (LET).

Materials And Methods: V79 cells were irradiated in monolayer with monoenergetic proton, deuteron, helium-3 or helium-4 ion beams, each at two different energy values. Gamma rays were used as reference radiation.

Inactivation of human normal and tumour cells irradiated with low energy protons.

Purpose: To analyse the cell inactivation frequencies induced by low energy protons in human cells with different sensitivity to photon radiation.

Materials And Methods: Four human cell lines with various sensitivities to photon irradiation were used: the SCC25 and SQ20B derived from human epithelium tumours of the tongue and larynx, respectively, and the normal lines M/10, derived from human mammary epithelium, and HF19 derived from a lung fibroblast. The cells were irradiated with y-rays and proton beams with linear energy transfer (LET) from 7 to 33 keV/microm.

Micronuclei, CREST-positive micronuclei and cell inactivation induced in Chinese hamster cells by radiation with different quality.

Purpose: To study the relative biological effectiveness-linear energy transfer (RBE-LET) relationship for micronuclei (MN) and cell inactivation, in Chinese hamster cells irradiated with low-energy protons (0.88 and 5.04 MeV, at the cell entrance surface).

RBE-LET relationships for cell inactivation and mutation induced by low energy protons in V79 cells: further results at the LNL facility.

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 were irradiated in mono-layer on mylar coated stainless steel petri dishes, in air. Inactivation data were obtained at 7.