Researchers have developed a new positron emission tomography (PET) tracer, 4-N-[¹⁸F]FDG-PBA, designed to improve imaging of liver tumors, and reported encouraging results in preclinical tests. The work, published as a research article in EJNMMI Radiopharmacy and Chemistry, addresses a well-known weakness of the standard PET imaging agent [¹⁸F]FDG: it accumulates strongly in healthy liver tissue, which can obscure tumors and compromise diagnostic accuracy in the hepatic region.
The new tracer was created by conjugating [¹⁸F]FDG with 4-aminophenylboronic acid, abbreviated PBA. According to the study, the total preparation time was approximately 40 minutes, with a decay-uncorrected radiochemical yield of 10 ± 5 percent across more than three preparations and a radiochemical purity exceeding 95 percent.
In both in vitro and in vivo assays, 4-N-[¹⁸F]FDG-PBA displayed high stability, with no observable defluorination, the authors report.
Cellular uptake experiments in H22 hepatoma cells showed that the probe accumulates rapidly in tumor cells. A key mechanistic finding emerged when the researchers blocked glucose transporter 1 (GLUT-1), the transporter responsible for cellular uptake of conventional [¹⁸F]FDG, using the inhibitor STF-31. Uptake of the new tracer fell by only 2.1 percent, a change that was not statistically significant (p = 0.13). This indicates that 4-N-[¹⁸F]FDG-PBA relies on a transmembrane transport mechanism distinct from that of [¹⁸F]FDG and does not depend on GLUT-1.
The team then evaluated the tracer in tumor-bearing mouse models using biodistribution analysis and micro-PET/CT imaging. These experiments showed that the compound is eliminated primarily through the renal-urinary system.
Importantly for the intended application, the tracer showed low hepatic background signal in the mouse models, along with what the authors describe as superior tumor visualization capability and favorable tumor-to-background ratios for liver tumor imaging. Low background uptake in the liver is precisely the property that conventional [¹⁸F]FDG lacks, and it is the central rationale for developing this alternative agent.
The authors conclude that 4-N-[¹⁸F]FDG-PBA possesses excellent stability, favorable pharmacokinetic characteristics, and a GLUT-independent tumor uptake mechanism, properties that together make it a promising novel radiotracer for high-precision liver tumor imaging.
Several caveats frame these findings. All results reported here come from preclinical work: chemical synthesis, cell-line experiments in H22 hepatoma cells, and studies in tumor-bearing mice. Performance in rodents does not establish safety, dosimetry, or diagnostic accuracy in humans, and clinical translation would require further validation studies.
Within those limits, the study offers a mechanistically interesting addition to the liver imaging toolkit. The findings establish a preclinical foundation that future studies in human subjects would need to build upon.
Subject of Research: Development and preclinical evaluation of the PET tracer 4-N-[¹⁸F]FDG-PBA for liver tumor imaging
Article Title: Radiosynthesis and preclinical evaluation of 4-N-[¹⁸F]FDG-PBA as a novel PET tracer for tumor imaging
Article References: Dong, W., Shen, C., Chang, R., Zhang, Z., Niu, C., Duan, X., & Guo, Y. (2026). Radiosynthesis and preclinical evaluation of 4-N-[¹⁸F]FDG-PBA as a novel PET tracer for tumor imaging. EJNMMI Radiopharmacy and Chemistry. https://doi.org/10.1186/s41181-026-00500-9
Image Credits: AI Generated
DOI: 10.1186/s41181-026-00500-9
Keywords: PET imaging, radiotracer, 4-N-[18F]FDG-PBA, liver tumor imaging, GLUT-1, H22 hepatoma cells, micro-PET/CT, biodistribution, radiochemical yield, fluorine-18, preclinical evaluation, renal clearance
News Source: Nathaniel Bowman. (October 29, 2026). New fluorinated glucose-based PET tracer shows promise for liver tumor imaging in mice. Scienmag.
