Small animal absorbed radiation dose from serial micro-computed tomography imaging.
OBJECTIVE
To determine the radiation dose to mouse cancer xenografts from serial micro-computed tomography (CT) examinations.


METHODS
A nude mouse with a 15-mm subcutaneous pancreatic cancer xenograft in the rightflank was used. Radiation exposure to the subcutaneous tumor and the mouse pancreas (to simulate an orthotopic pancreatic tumor model) was measured using lithium fluoride thermoluminescent dosimeters. Ultrafast micro-CT was performed using 80 kVp, 0.26 mA, 0.156 mm slice thickness, 256 slices, 0.7 mm Al filtration, and 60-second image acquisition time (15 mA second). Micro-CT imaging acquisitions were repeated four times.


RESULTS
We measured consistently low tumor doses (0.014 to 0.02 Gy; average=0.017 Gy) per scan. Orthotopic doses in the region of the pancreas were also consistently low (0.014 to 0.018 Gy; average=0.016 Gy) per scan.


CONCLUSIONS
Radiation doses delivered during ultrafast micro-CT serial imaging in the mouse are low and are likely below the threshold to affect tumor growth.
Carlson
Stephanie K
SK
Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. scarlson@mayo.edu
Classic
Kelly L
KL
Bender
Claire E
CE
Russell
Stephen J
SJ
D000818:Animals; D005260:Female; D051379:Mice; D009369:Neoplasms / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014183:Transplantation, Heterologous