Inactivation of C3H10T1/2 cells by low energy protons and deuterons.
OBJECTIVE
To determine the RBE-LET relationship for C3H10T1/2 cell inactivation by protons in the LET range 11-33 keV/microm and to compare inactivation frequencies induced in C3H10T1/2 cells by protons and deuterons at two matching LET values in the range 11-20 keV/microm.


METHODS
C3H10T1/2 cells were irradiated with protons and deuterons at the radiobiological facility set up at the 7MV Van de Graaff accelerator at the LNL, Legnaro, Padova. Gamma rays from 60Co were used as reference radiation.


RESULTS
Proton RBE values (alpha/alphagamma) for inactivation of C3H10T1/2 cells are constant around a value of 2 between 11 and 20 keV/microm and then rise sharply to reach a value of 4.2+/-1.0 at 33 keV/microm. Deuteron RBE values are 1.7+/-0.4 and 2.2+/-0.6 at LET values of 13 and 18 keV/microm respectively.


CONCLUSIONS
Proton RBE values with C3H10T1/2 cells are significantly larger than unity at LET values as low as 11 keV/microm. No difference in effectiveness for inactivation of C3H10T1/2 has been found between protons and deuterons at two LET values in the range 10-20 keV/microm.
Bettega
D
D
Dipartimento di Fisica dell'Università di Milano and INFN Sezione di Milano.
Calzolari
P
P
Marchesini
R
R
Noris Chiorda
G L
GL
Piazzolla
A
A
Tallone
L
L
Cera
F
F
Cherubini
R
R
Dalla Vecchia
M
M
Favaretto
S
S
Tiveron
P
P
D000818:Animals; D002470:Cell Survival / Q000528:radiation effects*; D002478:Cells, Cultured / Q000528:radiation effects / Q000648:ultrastructure; D003903:Deuterium; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D018499:Linear Energy Transfer; D051379:Mice; D008809:Mice, Inbred C3H; D010315:Particle Accelerators; D011522:Protons; D012062:Relative Biological Effectiveness
D011522:Protons; D003903:Deuterium