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WE‐E‐BRE‐03: Biological Validation of a Novel High‐Throughput Irradiator for Predictive Radiation Sensitivity Bioassays
Author(s) -
Fowler TL,
Martin JA,
Shepard AJ,
Bailey AM,
Nickel KP,
Kimple RJ,
Bednarz BP
Publication year - 2014
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4889432
Subject(s) - bioassay , dna damage , reactive oxygen species , dna repair , irradiation , radiation sensitivity , radiobiology , dosimetry , nuclear medicine , radiation therapy , dna , biomedical engineering , medicine , biology , microbiology and biotechnology , genetics , surgery , physics , nuclear physics
Purpose: The large dose‐response variation in both tumor and normal cells between individual patients has led to the recent implementation of predictive bioassays of patient‐specific radiation sensitivity in order to personalize radiation therapy. This exciting new clinical paradigm has led us to develop a novel high‐throughput, variable dose‐rate irradiator to accompany these efforts. Here we present the biological validation of this irradiator through the use of human cells as a relative dosimeter assessed by two metrics, DNA double‐strand break repair pathway modulation and intercellular reactive oxygen species production. Methods: Immortalized human tonsilar epithelial cells were cultured in 96‐well micro titer plates and irradiated in groups of eight wells to absorbed doses of 0, 0.5, 1, 2, 4, and 8 Gy. High‐throughput immunofluorescent microscopy was used to detect γH2AX, a DNA double‐strand break repair mechanism recruiter. The same analysis was performed with the cells stained with CM‐H2DCFDA that produces a fluorescent adduct when exposed to reactive oxygen species during the irradiation cycle. Results: Irradiations of the immortalized human tonsilar epithelial cells at absorbed doses of 0, 0.5, 1, 2, 4, and 8 Gy produced excellent linearity in γH2AX and CM‐H2DCFDA with R2 values of 0.9939 and 0.9595 respectively. Single cell gel electrophoresis experimentation for the detection of physical DNA double‐strand breaks in ongoing. Conclusions: This work indicates significant potential for our high‐throughput variable dose rate irradiator for patient‐specific predictive radiation sensitivity bioassays. This irradiator provides a powerful tool by increasing the efficiency and number of assay techniques available to help personalize radiation therapy.