A Head-to-Head Comparison of Detection Rate and Tumor Uptake of FAPI, PSMA, and FDG PET/CT in Newly Diagnosed High-risk Prostate Cancer
Wei Zhang, Yanhao Dong, Lian Xu, Penghui Liao, Xinxing Du, Cong Hu, Zehong Peng, Lihan Lai, Zhicheng Zheng, Jiahua Pan, Yinjie Zhu, Jianjun Liu, Ruohua Chen, Liang Dong, Wei XuePurpose:
This study was designed to investigate the detection rate and tumor uptake of 18 F-AlF-NOTA-De-FAPI PET/CT in newly diagnosed high-risk prostate cancer (PCa), compared with 68 Ga-PSMA-11 and 18 F-FDG PET/CT.
Patients and Methods:
This study enrolled 48 patients with biopsy-diagnosed, treatment-naive high-risk PCa who underwent 18 F-AlF-NOTA-De-FAPI, 68 Ga-PSMA-11, and 18 F-FDG PET/CT between April and December 2024. A head-to-head comparison of detection rate and tumor uptake was performed among the 3 tracers. In addition, 18 F-AlF-NOTA-De-FAPI and 68 Ga-PSMA-11 dual-tracer PET was used to characterize the imaging phenotypes of each lesion and interlesional heterogeneity.
Results:
A total of 477 lesions were detected by the 3 PET tracers. 68 Ga-PSMA-11 exhibited the highest overall detection rate (96.4%), followed by 18 F-AlF-NOTA-De-FAPI (81.1%) and 18 F-FDG (66.0%). A total of 17 68 Ga-PSMA-11-negative lesions were identified in 8 patients, all of which were detected by 18 F-AlF-NOTA-De-FAPI, whereas only 12 were detected by 18 F-FDG. Combined 68 Ga-PSMA-11 and 18 F-AlF-NOTA-De-FAPI PET identified all lesions detected by triple-tracer PET. Based on relative tracer dominance of dual-tracer PET, patients were classified as PSMA-dominant (n=23), FAPI-dominant (n=5), or mixed phenotype (n=20). The mixed phenotype with marked interlesional heterogeneity might be associated with more advanced clinical characteristics, with a higher proportion of metastatic disease and a greater metastatic burden.
Conclusions:
18 F-AlF-NOTA-De-FAPI is a promising PET tracer for newly diagnosed high-risk PCa. It may improve the detection rate of 68 Ga-PSMA-11-negative lesions and provide complementary information that could reflect interlesional heterogeneity. The clinical value of combining 18 F-AlF-NOTA-De-FAPI and 68 Ga-PSMA-11 PET requires further validation in larger prospective cohorts.