[BeO-OSL detectors for dose measurements in cell cultures].
OBJECTIVE
The absorbed dose is an important parameter in experiments involving irradiation of cells in vitro with unsealed radionuclides. Typically, this is estimated with a model calculation, although the results thus obtained cannot be verified. Generally used real-time measurement methods are not applicable in this setting. A new detector material with in vitro suitability is the subject of this work.


METHODS
Optically-stimulated luminescence (OSL) dosimeters based on beryllium oxide (BeO) were used for dose measurement in cell cultures exposed to unsealed radionuclides. Their qualitative properties (e. g. energy-dependent count rate sensitivity, fading, contamination by radioactive liquids) were determined and compared to the results of a Monte Carlo simulation (using AMOS software). OSL dosimeters were tested in common cell culture setups with a known geometry.


RESULTS
Dose reproducibility of the OSL dosimeters was +/-1.5%. Fading at room temperature was 0.07% per day. Dose loss (optically-stimulated deletion) under ambient lighting conditions was 0.5% per minute. The Monte Carlo simulation for the relative sensitivity at different beta energies provided corresponding results to those obtained with the OSL dosimeters. Dose profile measurements using a 6 well plate and 14 ml PP tube showed that the geometry of the cell culture vessel has a marked influence on dose distribution with 188Re.


CONCLUSIONS
A new dosimeter system was calibrated with beta-emitters of different energy. It turned out as suitable for measuring dose in liquids. The dose profile measurements obtained are suitably precise to be used as a check against theoretical dose calculations.
Klinik und Poliklinik für Nuklearmedizin, Universitätsklinikum Carl Gustav Carus, Fetscherstr. 74, 01307 Dresden, Germany. Michael.Andreeff@uniklinikum-dresden.de
M
M
Andreeff
D
D
Sommer
R
R
Freudenberg
U
U
Reichelt
J
J
Henniger
J
J
Kotzerke
D001608:Beryllium / Q000528:radiation effects*; D018929:Cell Culture Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
C032777:beryllium oxide; D001608:Beryllium