Comment on 'estimation of organ and effective dose due to Compton backscatter security scans' [Med. Phys. 39, 3396 (2012)]

摘要

In the June 2012 Issue of Medical Physics, Hoppe and Schmidt presented simulation-based estimates of the organ and effective dose from an x-ray backscatter scan using a Rapiscan Secure 1000 single pose system that is used in airports for the security screening of persons. The paper presented Monte Carlo modeling results based upon spectrum and air kerma measurements presented in the literature. We reviewed the methods employed by the authors and conclude that the source fluence was overestimated by a factor of about 3.5 due to a mistake in the air kerma normalization. Another error factor was introduced due to a misinterpretation of the reference location that the air kerma was measured; this effectively underestimated source fluence by about 2.5. These fluence values in turn led to errors in the reported organ and effective doses.