Imaging pancreatic cancer with [¹⁸F]F-AlF-NOTA-FAPI-04 positron emission tomography/computed tomography (PET/CT):...

This study aimed to evaluate the diagnostic performance of [¹⁸F]F-AlF-NOTA-FAPI-04 positron emission tomography/computed tomography (PET/CT) in pancreatic cancer by comparing its uptake patterns with other tumour types and analysing intrapancreatic heterogeneity. The study also explored possible causes of physiological pancreatic uptake to aid in distinguishing non-malignant uptake from true pathological lesions and improve diagnostic accuracy.

In this prospective study, 103 treatment-naïve cancer patients (36 pancreatic, 67 nonpancreatic) underwent [¹⁸F] AlF-NOTA-FAPI-04 PET/CT. Metabolic tumour volume (MTV), standardised uptake values (SUV), and total lesion Fibroblast Activation Protein (FAP) expression (TLF) were analysed. Hierarchical regression and independent t-tests were applied to assess correlations between imaging features and clinicopathological characteristics.

Pancreatic cancer exhibited significantly higher SUVmax (16.3 ± 4.4 vs 5.0 ± 4.3, P<0.001), SUVmean (6.3 ± 2.3 vs 1.7 ± 1.2, P<0.001), and TLF (321.5 ± 251.3 vs 89.4 ± 62.1, P<0.001) compared to non-pancreatic tumors. Tumours in the pancreatic head/neck region demonstrated greater [68 G]G-FAPI-04 uptake than body/tail lesions (SUVmean: 7.7 ± 3.1 vs 6.3 ± 2.9, P=0.016). TLF correlated positively with tumour size and stage (F = 2.576, P=0.027). Mild to moderate pancreatic uptake was also observed in a subset of patients with hepatocellular carcinoma, partially correlating with elevated alkaline phosphatase (ALP) levels.

[¹⁸F]F-AlF-NOTA-FAPI-04 PET/CT shows high specificity for pancreatic ductal adenocarcinoma, particularly in head/neck tumours. Physiological or nonspecific pancreatic uptake in nonpancreatic malignancies warrants careful interpretation to avoid misdiagnosis.