Bone Strength Assessment Based on CT Images Using a Network Spring Model for Radiation Therapy Patients
Yan Song (University of Houston, USA), Boris Muller (Memorial Sloan-Kettering Cancer Center, USA), Chandra Burman (Memorial Sloan-Kettering Cancer Center, USA), Borys Mychalczak (Memorial Sloan-Kettering Cancer Center, USA) and Yulin Song (Memorial Sloan-Kettering Cancer Center, USA)
Copyright: © 2008
In radiation therapy, especially using intensity modulated radiation therapy (IMRT), a high dose of ionizing radiation is delivered to the patient and, therefore, the bone health is a major concern for young patients. What is more, many tumors, like soft tissue sarcomas, are located in close proximity to bone. High energy radiation unavoidably exerts negative impacts not only on bone physiological properties, but also on its mechanical and structural properties. As a result, bone fracture risk for these patients is increased significantly. Thus, it is necessary to develop a quantitative noninvasive screening technique to identify these high risk patients.
Key Terms in this Chapter
Strain: The relative deformation (size or shape) of a material under stress.
Young’s Modulus: The ratio of material stress to strain (when strain is not very large). It is a measure of material stiffness.
Stress: The internal distribution of force over a unit area. It is the interaction response to the external loading.
Voxel: The smallest volume element in a 3-dimensional image space determined by the image resolution. It is the basic image element of the object reconstructed from a series of 2-D CT images.
Intensity Modulated Radiation Therapy (IMRT): A new radiation therapy technique based on the concept of inverse treatment planning. By optimizing a set of dose-volume constraints and dose limits, the radiation intensity can be finely modulated so that the dose distribution matches the geometrical distribution of the target volume. Therefore, the maximum dose of radiation can be delivered and the side effect can be minimized.