December 5, 2022
@
12:00 PM
–
1:00 PM
Imaging Oxygen in Cancer: for Radiotherapy & Surgery
Brian W. Pogue, PhD
Chair
Department of Medical Physics
University of Wisconsin-Madison
Oxygen is one of the ubiquitous molecules in life, but yet one of the most challenging to quantify. This is because of the temporal and spatial microheterogeneity and because most tools developed to measure it only access a small fraction of the information, or worse, alter the measurement as it is happening. This talk will review tools for this purpose, and focus on molecular sensors for oxygen measurement that have applications in science and medicine.
In the field of surgical oncology, many advances have occurred in the field of molecular guidance, where fluorescence from reporters can add important specificity of the signal. The breadth of systems being developed and advanced for fluorescence guidance in surgery is growing rapidly, and a review of these and their technical capabilities will be given. A recent discovery has been made that protoporphyrin IX (PpIX) shows that fluorescence can be produced only in areas of hypoxia with time-gated fluorescence capture. This delayed fluorescence emission lifetime exists when going from oxygenated to hypoxic tissue, and the advancement of this technique is one of the few ubiquitous metabolic signals from most oncologic tissues.
In the field of radiation therapy, a rapidly emerging aspect is what is called ‘FLASH’ radiotherapy, where the dose to tissue is given in milliseconds. It has been shown that this approach radically changes the radiobiological response, sparing normal tissues. The mechanism for this is implicated to be oxygen consumption effects during the irradiation, and a range of tools have been used to quantify this. The effect of oxygen dynamics in radiotherapy will be shown, and methods to quantify the dominance of oxygen in the damage is being discovered.
Print PDF