Characterization of a novel phantom for three-dimensional in vitro cell experiments.
A novel intensity-modulated radiation therapy (IMRT) phantom for use in three-dimensional in vitro cell experiments, based on a commercially available system (CIRS Inc., Norfolk, VA), was designed and fabricated. The water-equivalent plastic phantom can, with a set of water-equivalent plastic inserts, enclose 1-3 multi-well tissue culture plates. Dosimetry within the phantom was assessed using thermoluminescence dosimeters (TLDs) and film. The phantom was loaded with three tissue culture plates, and an array of TLDs or a set of three films was placed underneath each plate within the phantom, and then irradiated using an IMRT plan created for it. Measured doses from each dosimeter were compared to those acquired from the treatment planning system. The percent differences between TLD measurements and the corresponding points in the treatment plan ranged from 1.3% to 2.9%, differences which did not show statistical significance. Average point-by-point percent dose differences for each film plane ranged from 1.6% to 3.1%. The percentage dose difference for which 95% of the points in the film matched those corresponding to the calculated dose plane to within 3.0% ranged from 2.8% to 4.2%. The good agreement between predicted and measured dose shows that the phantom is a useful and efficient tool for three-dimensional in vitro cell experiments.
Altman
Michael B
MB
Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, USA.
Vesper
Benjamin J
BJ
Smith
Brett D
BD
Stinauer
Michelle A
MA
Pelizzari
Charles A
CA
Aydogan
Bulent
B
Reft
Chester S
CS
Radosevich
James A
JA
Chmura
Steven J
SJ
Roeske
John C
JC
D002478:Cells, Cultured; D019047:Phantoms, Imaging; D050397:Radiotherapy, Intensity-Modulated / Q000295:instrumentation / Q000379:methods*