Comparative evaluation of bone and some materials used as bone tissue substitutes in radiotherapy and radiological applications

In this work, a study of radiation scattering properties of some real bone tissues and bone tissue-equivalent materials was carried out. The selected real bone tissues which are six in number include cortical bone, humerus, mandible, cartilage, yellow marrow and spongiosa. The tissue-equivalent materials include red marrow/G1, red marrow/L3, red marrow/SR4, aluminium, Cameron wax, facey liquid, magnesium, plaster of Paris, poll resin, poly (vinyl chloride), pyrex, Shonka plastic (B100) and Spiers liquid. Monte-Carlo software package (EGSnrc) was used to determine and study the scattering properties of the selected real bone tissue and its substitutes with the view of establishing an equivalence between them. The simulation of the transport of X-ray photons considered photoelectric absorption, coherent scattering and Compton scattering. The incident photon energy used in the simulation of angular distributions of photons scattered by these bone tissues is 17.44 keV. The computational result shows that the scattering properties of some of the bone tissue equivalent materials are similar to some of the real bone tissues. It revealed that the peak positions for real bone tissues: cortical bone, cartilage, yellow marrow and spongiosa gotten from the angular dispersive scattering studies were found to occur at 0.19286 Å⁻¹, 0.17331 Å⁻¹, 0.1341 Å⁻¹ and 0.3667 Å⁻¹ respectively. Those obtained from the bone tissue-equivalent materials: magnesium, red marrow/G1 and Cameron wax are 0.19286 Å⁻¹, 0.23186 Å⁻¹ and 0.17331 Å⁻¹ respectively. As a result of closeness in the scattering properties, it was concluded that magnesium and poll resin bone tissue substitutes can simulate the cortical bone tissue. Red marrow/G1, red marrow/L3 and Cameron wax bone tissue substitutes can be used to simulate the cartilage bone tissue. Red marrow/S4 and Cameron wax bone tissue substitutes are good substitutes for yellow marrow bone tissue while pyrex is not a good substitute for any of the bones. Based on the wide disparity in scattering properties studies obtained in this work, it was not possible to identify a good substitute for the humerus, mandible and spongiosa real bone tissues from among the selected tissue equivalent materials.