Radiobiologic Factors to Consider with Total Marrow Irradiation

Total Marrow Irradiation (TMI) is an emerging, technologically advanced radiation conditioning regimen that can simultaneously delivery radiation to specific body structures with high hematological disease burden and reduce radiation to organs at risk in order to maintain function. The result is an extraordinary ability to modulate the radiation dose to a very large extended target through the body, effecting a paradigm shift in the treatment of hematological malignancies. However, the radiobiological relevance is beginning to emerge and will be a valuable step for advancing the clinical benefit of this new technology. Toward this goal, we address the pathology of hematological disease, the historical relevance of total body irradiation and its limitations that led to TMI development, and key factors that are associated with radiobiological assessment. Furthermore, a vision of the future of radiology is discussed, in which we are expected to achieve an improved understanding of the complex and extended nature of disease and its associated microenvironment.