Assessment of liver graft hypoxia via 18F-FMISO PET‑CT imaging

Objective: drawing on existing literature and the clinical use of radiopharmaceutical (RFP) ¹⁸F-FMISO in on- cology, this pilot study aims to assess the feasibility of using non-invasive PET-CT imaging to detect hypoxia in liver grafts resulting from ischemia-reperfusion injury.

Materials and methods. 18F-FMISO uptake in tumors, as visualized by PET-CT, enables the generation of quantitative maps of tissue hypoxia, a technique that is increa- singly being explored to guide radiation therapy planning. As part of refining the study methodology, the research team successfully obtained the first PET-CT images demonstrating ¹⁸F-FMISO uptake in the liver of a patient at a late postoperative stage following liver transplantation.

Results. A positive indication of transplant hypoxia was defined as an increase in both the mean and maximum standardized uptake values (SUVs) when measured at 180 minutes post-intravenous injection of the radiopharmaceutical, compared to measurements at 90 minutes. Two imaging series – CT and PET – were acquired. Diffuse uptake of the radiopharmaceutical was observed in the liver, with greater tracer retention relative to background at 180 minutes compared to 90 minutes post-injection.

Conclusion. The findings suggest the presence of transplant hypoxia despite the absence of biochemical abnor- malities. This technique shows promise as a non-invasive diagnostic tool for detecting hypoxic changes in liver grafts. However, further optimization and validation of the technique are necessary.

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