Protoporphyrin IX delayed fluorescence imaging: a modality for hypoxia-based surgical guidance (Journal of Biomedical Optics)

Arthur Pétusseau, Petr Bruza, Brian Pogue

Short Abstract: This study presents the first real-time imaging of tumor hypoxia using delayed fluorescence from PpIX, showing high contrast in a pancreatic cancer model. By mapping tissue oxygen levels, the method provides strong tumor contrast, offering a promising tool for oxygen-based surgical guidance.

Pressure-enhanced sensing of tissue oxygenation via endogenous porphyrin: Implications for dynamic visualization of cancer in surgery (Proceedings of the National Academy of Science)

Arthur Pétusseau, Marien Ochoa, Matthew Reed, Marvin M. Doyley, Tayyaba Hasan, Petr Bruza, Brian W. Pogue

Short Abstract: This study introduces a novel method, PRESTO, for visualizing tissue hypoxia using pressure-enhanced delayed fluorescence from ALA-induced PpIX. By applying light pressure to temporarily halt blood flow, the technique highlights poorly oxygenated tissue, enabling strong contrast between tumors and healthy tissue. Demonstrated across five tumor models, this approach offers a powerful new tool for real-time cancer detection and may have broader applications in vascular and hypoxic diseases.

Imaging of hypoxia, oxygen consumption and recovery in vivo during ALA-photodynamic therapy using delayed fluorescence of Protoporphyrin IX (Photodiagnosis and Photodynamic Therapy)

Marek Scholz, Arthur F. Petusseau, Jason R. Gunn, M. Shane Chapman, Brian W. Pogue

Short Abstract: This study demonstrates real-time monitoring of intracellular oxygen during photodynamic therapy (PDT) using time-gated imaging of delayed fluorescence (DF) of protoporphyrin IX (PpIX). Applied in mice and human skin, the method reveals dose-dependent oxygen depletion and recovery, with high spatial and temporal resolution. This approach enables direct pO₂ imaging during PDT and holds strong clinical potential to improve treatment efficacy..

Intracellular Oxygen Transient Quantification in Vivo During Ultra-High Dose Rate FLASH Radiation Therapy (International Journal of Radiation Oncology*Biology*Physics)

Arthur F. Petusseau, Megan Clark, Petr Bruza, David Gladstone, Brian W. Pogue

Short Abstract: This study presents a method to measure intracellular oxygen depletion during ultra-high dose rate (FLASH) radiation using PpIX delayed fluorescence. In mice, intracellular pO2 changes closely matched extracellular pO2 measured by oxyphor phosphorescence, both scaling with dose. This technique offers a new way to track oxygen dynamics near DNA during FLASH, with potential for human translation.

Dynamic oxygen assessment techniques enable determination of anesthesia’s impact on tissue (Research Square)

Megan A Clark, Armin D Tavakkoli, Arthur F Petusseau, Augustino V Scorzo, Alireza Kheirollah, Scott C Davis, Rendall R Strawbridge, Petr Bruza, Brian W Pogue, David J Gladstone, P Jack Hoopes

Short Abstract: This study quantifies how anesthesia type and timing affect tissue oxygenation in mice, which can influence radiotherapy outcomes. Using Oxyphor PdG4 and PpIX delayed fluorescence, both extracellular and intracellular pO₂ levels were tracked. Isoflurane anesthesia caused a significant pO₂ rise over 10 minutes, while ketamine/xylazine maintained steady, lower pO₂. Results highlight the importance of standardizing anesthesia protocols to reduce variability in radiation response.