CXCR4-targeted PET/CT with [¹⁸F]AlF-NOTA-QHY-04 in primary central nervous system lymphoma: a prospective comparison with MRI and [¹⁸F]FDG PET/CT.
This study aimed to evaluate the diagnostic performance of [¹⁸F]AlF-NOTA-QHY-04 PET/CT, a novel CXCR4-targeted imaging agent, in detecting primary central nervous system lymphoma (PCNSL) at initial diagnosis and suspected recurrence, in comparison with contrast-enhanced magnetic resonance imaging (CE-MRI) and [¹⁸F]FDG PET/CT.
We prospectively enrolled patients with suspected PCNSL between September 2022 and December 2024. A total of 29 patients underwent both CE-MRI and [¹⁸F]AlF-NOTA-QHY-04 PET/CT, with 20 patients also receiving [¹⁸F]FDG PET/CT. Biopsy pathology served as the reference standard for newly diagnosed lesions. Recurrence was assessed using a composite reference standard based on CE-MRI, clinical follow-up, and cerebrospinal fluid (CSF) findings when available; an exploratory sensitivity analysis excluded MRI-dependent cases. Imaging parameters including the maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), and tumor-to-background ratios (TBR) were calculated. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis and compared.
Six treatment-naïve patients (14 lesions) and 16 patients with recurrence (16 lesions) were confirmed, along with 7 patients without recurrence. Both primary and recurrent lesions showed intense tracer uptake on [¹⁸F]AlF-NOTA-QHY-04 PET/CT, characterized by notably high TBR. In the 20-patient subgroup undergoing both PET scans, [¹⁸F]AlF-NOTA-QHY-04 demonstrated significantly lower absolute SUVmax compared to [¹⁸F]FDG (median: 2.42 vs. 11.73, P < 0.001) but a substantially higher TBR-SUVmax (median: 42.75 vs. 1.07, P < 0.001), leading to the identification of more positive lesions (14 vs. 7, P = 0.023). Relative to the composite reference standard, [¹⁸F]AlF-NOTA-QHY-04 PET/CT achieved sensitivity and accuracy (87.50% and 90.91%, respectively) comparable to CE-MRI (100% for both, P > 0.05) and significantly superior to [¹⁸F]FDG PET/CT (43.75% and 59.09%, P = 0.023). ROC analysis identified [¹⁸F]AlF-NOTA-QHY-04 SUVmax as the optimal diagnostic parameter (AUC = 0.979).
[¹⁸F]AlF-NOTA-QHY-04 PET/CT demonstrated high tumor-to-background contrast in PCNSL, consistent with its low background brain uptake. It shows diagnostic accuracy comparable to CE-MRI and significantly superior to [¹⁸F]FDG PET/CT, demonstrating high potential as a valuable imaging tool for the diagnosis and restaging of PCNSL.
We prospectively enrolled patients with suspected PCNSL between September 2022 and December 2024. A total of 29 patients underwent both CE-MRI and [¹⁸F]AlF-NOTA-QHY-04 PET/CT, with 20 patients also receiving [¹⁸F]FDG PET/CT. Biopsy pathology served as the reference standard for newly diagnosed lesions. Recurrence was assessed using a composite reference standard based on CE-MRI, clinical follow-up, and cerebrospinal fluid (CSF) findings when available; an exploratory sensitivity analysis excluded MRI-dependent cases. Imaging parameters including the maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), and tumor-to-background ratios (TBR) were calculated. Diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis and compared.
Six treatment-naïve patients (14 lesions) and 16 patients with recurrence (16 lesions) were confirmed, along with 7 patients without recurrence. Both primary and recurrent lesions showed intense tracer uptake on [¹⁸F]AlF-NOTA-QHY-04 PET/CT, characterized by notably high TBR. In the 20-patient subgroup undergoing both PET scans, [¹⁸F]AlF-NOTA-QHY-04 demonstrated significantly lower absolute SUVmax compared to [¹⁸F]FDG (median: 2.42 vs. 11.73, P < 0.001) but a substantially higher TBR-SUVmax (median: 42.75 vs. 1.07, P < 0.001), leading to the identification of more positive lesions (14 vs. 7, P = 0.023). Relative to the composite reference standard, [¹⁸F]AlF-NOTA-QHY-04 PET/CT achieved sensitivity and accuracy (87.50% and 90.91%, respectively) comparable to CE-MRI (100% for both, P > 0.05) and significantly superior to [¹⁸F]FDG PET/CT (43.75% and 59.09%, P = 0.023). ROC analysis identified [¹⁸F]AlF-NOTA-QHY-04 SUVmax as the optimal diagnostic parameter (AUC = 0.979).
[¹⁸F]AlF-NOTA-QHY-04 PET/CT demonstrated high tumor-to-background contrast in PCNSL, consistent with its low background brain uptake. It shows diagnostic accuracy comparable to CE-MRI and significantly superior to [¹⁸F]FDG PET/CT, demonstrating high potential as a valuable imaging tool for the diagnosis and restaging of PCNSL.
Authors
Pang Pang, Xing Xing, Liu Liu, Zhao Zhao, Li Li, Xu Xu, Pei Pei, Yu Yu, Chen Chen, Liu Liu
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