A two-dimensional array of memory cells may be used to implement a spatial dosimeter. The two-dimensional array of cells may be implemented by an integrated circuit memory. Because of the relatively small size of the integrated circuit memory, the resolution of the resulting array may be less than 100 nanometers. The change in threshold voltage of each of the cells, as a result of radiation exposure, may be used to calculate the dose seen at each cell, allowing dose profiles in two dimensions with sub-micrometer resolution.