ABSTRACT
Microdosimetry measures the random processes of energy deposition in small volumes that mimic sub-cellular sizes, therefore it may be used to perform routine verification of the LET or relative biological effectiveness distributions calculated by the treatment planning systems. Microdosimetry measures the energy deposited in a microscopic volume as a stochastic process, and results are presented both as single and as multiple-event spectra. However, the measurement of the energy deposited locally in individual events gives more information on the radiation quality, and it is therefore generally preferred. Microdosimeters can be characterized by comparing the experimental microdosimetric spectra acquired in controlled conditions to the ones simulated by reproducing the experiment as strictly as possible. The impact of the different radiation qualities on the tissue target is evaluated through computations which refer to the models of radiation effectiveness. Simulations offer a high degree of flexibility; numerical experiments can be performed by turning specific terms on or off, isolating physical effects.
