ABSTRACT
The entire skeleton in an adult consists of 200 distinct bones divisible into four classes: long, short, flat and irregular bones. Radiosensitive cells in the human skeletal system have been identified as haematopoietic cells present in bone marrow, endosteal cells lying close to bone surfaces and epithelial cells close to bone surfaces in the air sinuses of the skull. For directly ionizing radiations, there are two approaches to calculate energy deposited in the sensitive regions of the skeletal system. The first is to focus the modelling on closely representing the anatomical microstructures of the skeletal system and to couple the model to a Monte Carlo particle transport code. The second approach is to model the particle transport in such a way that the traversed distance across a given microscopic region by a particle matches exactly the real path of the particle in the skeletal microstructure. Patient-specific determination of marrow cellularity and marrow reserve is important to improve bone dosimetry calculations.
