The current international biodosimetry gold standard for assessing ionizing radiation (IR) exposure in humans is the Dicentric Chromosome Aberration Assay (DCAA). However, this assay is neither simple or fast. It requires substantial expertise and experienced technical personnel, as well as the infrastructure of a well outfitted bio-research laboratory. Furthermore, it's most effective at assessing acute exposures to low-LET IR, with sensitivity down to ~0.1Gy for acute exposure. It is less effective or accurate with chronic exposures that occur over extended time frames, or acute exposures that happened a substantial time in the past. All of this of course pre-supposes that you know that the genotoxic exposure is limited to IR and not some other DNA breaking agent or some combination of IR and other (chemical) genotoxic DNA breaking agents.

Without adopting a similar assessment method for the cells recovered in the buccal smear, and doing extensive quality control and characterization of the method, you will be hard pressed to establish it as a viable alternative to the alreadyl established and officially adopted DCAA.

For your information, the Special Issue on the European European Network of Biodosimetry (RENEB) project guest edited by Drs Ulrike Kulka and Andrzej Wojcik has just become available online as the January 2017 issue of International Journal of Radiation Biology. All papers in this special issue are freely downloadable.

http://www.tandfonline.com/toc/irab20/93/1