Radiobiology of alpha particles. IV. Cell inactivation by alpha particles of energies 0.4-3.5 MeV.

RAJU, M. R., EISEN, Y., CARPENTER, S., JARRETT, K., AND HARVEY, W. F. Radiobiology of a Particles. IV. Cell Inactivation by a Particles of Energies 0.4-3.5 MeV. Radiat. Res. 133, 289-296 (1993). In this report the effectiveness of low-energy a particles in the range 0.4 to 3.5 MeV for cell killing is investigated. Four cell lines of different nuclear dimensions (AG1522, C3H 10T1/2, CHO-10B, and HS-23) are studied. Monte Carlo simulations are carried out to interpret the experimental results. They are presented as a function of dose to the nucleus, the total track length of a particles in the nucleus, and other parameters. It is found that the effectiveness of a particles for cell killing decreases with decreasing a-particle energy. The maximum RBE value is found to extend to LET values as high as 180 keV/um. Although the LET might be the same, the effectiveness of a particles for cell killing is higher in the ascending part of the Bragg curve compared to descending part of the Bragg curve. The terminal tracks of a particles are observed to be less effec