| Nuclear medicine encompasses numerous steps, with accuracy being a key component throughout. Exactitude in skeletal dosimetry is of importance due to the high radiosensitivity of the hematopoietic cells populating the marrow cavities within trabecular bone. In fact, active marrow is generally the dose limiting organ in both radioimmunotherapy and bone pain palliation.; Current research involving improvements in skeletal dosimetry is being pursued through nuclear magnetic resonance- (NMR) and computed tomography- (CT) imaging. Images acquired from these imaging modalities are coupled to Monte Carlo transport models to calculate S values for radionuclides localized within the skeleton. This is accomplished by in-vivo and in-vitro imaging of specific active marrow sites to acquire trabecular bone microstructure and to determine spongiosa volume. The spongiosa volumes are being calculated in order to develop a scaling factor that will relate the active marrow volume of a specific patient to that of a newly defined reference man.; Improvement to the International Commission on Radiological Protection Publication 70 reference parameters for red marrow volume has taken many paths since research was started at the University of Florida in 1995. This work proposes to aid in the improvement of skeletal dosimetry through (1) investigation of the surface-area voxel effect of digital images, (2) spongiosa volume determination, and (3) investigation of anthropomorphic measurements as scaling factors of spongiosa volumes. |
