Calculation of energy deposition in subcellular structures

Radionuclides emitting low energy electrons are very suitable for the study of the radiosensitivity of subcellular structures because the range of the said electrons is at subcellular level and the deposition of energy from the said sources has a highly localized character. A program was written in BASIC which allows to calculate the energy deposited in the nucleus, cytoplasma and in the whole cell. The output of the program is the value of energy deposited in the chosen volume. Incorporated in the program is a subprogram for the calculation of energy in concentric spheres with the source in the middle and the source library. The calculation methods are based on the slowing down approximation and on Berger's scaled point kernels functions. The calculations show that the cell nucleus as a whole cannot be considered as a sensitive target responsible for the cell death due to ionizing radiation but that DNA complexes with a nuclear membrane are such a target. (M.D.). 12 refs., 3 tabs., 4 figs