Whole-body tomographic fluorescence lifetime imaging of PD-L1 expression
Year: 2026
Type: article
Abstract: Noninvasive quantification of immune markers such as programmed death ligand-1 (PD-L1) remains a major challenge because conventional molecular imaging methods cannot readily distinguish target-bound from nonspecifically retained probes within the tumor microenvironment. Here, we establish a framework for noninvasive quantification of PD-L1 expression in deep-seated hepatocellular carcinoma (HCC) using asymptotic time-domain (ATD) fluorescence lifetime tomography. In vivo time-domain fluorescence imaging was performed in mice bearing orthotopic HCC tumors following administration of a PD-L1-targeted near-infrared fluorescent probe (αPDL1-800). Multi-exponential analysis of time-domain fluorescence data was used to derive four amplitude-based metrics of PD-L1 expression. Quantitative in vivo measurements obtained from ATD tomography were validated against ex vivo PD-L1 expression measured by Western blotting. Among the evaluated metrics, a normalized parameter that accounts for inter-lifetime crosstalk demonstrated the strongest correlation with ex vivo PD-L1 expression ( r 2 = 0.77). These findings establish a foundation for a noninvasive, nonionizing imaging approach to quantify immune biomarker expression and provide a framework for the longitudinal assessment of immunotherapy response and dynamic changes in the tumor immune microenvironment.
Source: npj Imaging
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,790
OpenAlex ID: W7223476643
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