Bone Marrow Angiogenesis in Acute Myeloid Leukemia - Evaluated by Dynamic Contrast Enhanced Magnetic Resonance (MR) Image

In malignant or neoplastic disease, angiogenesis is defined as the generation of new capillaries from preexisting blood vessels, e.g. by sprouting or by intusseption. Through the pioneering work of Folkman, it was recognized that angiogenesis plays an important role in tumor development, progression, and metastasis. It is also conceivable that there are forms or developmental stages of leukemia, multiple myeloma, or lymphomas that will progress independently of angiogenesis. Synthesis of angiogenesis activators, such as vascular endothelial growth factor (VEGF) and other angiogenic factors, such as basic fibroblast growth factor (bFGF), has been demonstrated for leukemia cells, non-Hodgkin's lymphoma, and myeloma cells. Microvessel density is also significantly elevated over normal controls with progressive increases according to the stages of myelodysplastic syndrome. Increased microvessel density (MVD) in the bone marrow was found in patients with multiple myeloma in comparison to normal controls and increased MVD is an adverse prognostic marker in multiple myeloma. However, the functional status of the blood vessel (e.g. permeability) cannot be determined by the above mentioned methods.