Survival of mammalian cells exposed to ultrahigh dose rates from a laser-produced plasma x-ray source.
OBJECTIVE
To determine whether intense laser-produced x rays have an increased radiation hazard.


METHODS
Mammalian cells were exposed to x rays from a laser-produced plasma that produced ultrahigh peak absorbed dose rates, up to a factor of 10(10) higher than those produced by conventional x rays used in imaging. The cell survival was studied as a function of the absorbed dose. The survival of mammalian cells exposed to high peak absorbed dose rates with laser-produced x rays was compared with the survival of cells exposed to standard absorbed dose rates with conventional x-ray sources. Comparative survival studies were performed by using a conventional x-ray tube and a cobalt 60 source. The absorbed doses in the irradiation field were measured with thermoluminescent dosimeters.


RESULTS
Cell survival following irradiation by filtered, laser-produced x rays with a high dose rate was not markedly different from the survival following irradiation by conventional sources. There was, however, a notable difference between the survival after exposure to filtered, laser-produced x rays and the survival after exposure to unfiltered laser-produced x rays.


CONCLUSIONS
Exposure to filtered, laser-produced x rays with a high dose rate does not lead to increased harm to mammalian cells exposed in vitro compared with the harm from exposure to x rays from conventional sources, which indicates that the use of high-power laser facilities for medical imaging is justified.
Tillman
C
C
Division of Atomic Physics, Lund Institute of Technology, Sweden.
Grafström
G
G
Jonsson
A C
AC
Jönsson
B A
BA
Mercer
I
I
Mattsson
S
S
Strand
S E
SE
Svanberg
S
S
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006168:Guinea Pigs; D007834:Lasers / Q000009:adverse effects*; D020714:Maximum Tolerated Dose; D011833:Radiation Injuries, Experimental / Q000209:etiology*