AUTHOR=Zhou Xing , Li YingChun , Jiang Xiao , Wang XiaoXiong , Chen ShiRong , Shen TaiPeng , You JinHui , Lu Hao , Liao Hong , Li Zeng , Cheng ZhuZhong 

TITLE=Intra-Individual Comparison of 18F-PSMA-1007 and 18F-FDG PET/CT in the Evaluation of Patients With Prostate Cancer

JOURNAL=Frontiers in Oncology

VOLUME=Volume 10 - 2020

YEAR=2021

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2020.585213

DOI=10.3389/fonc.2020.585213

ISSN=2234-943X

ABSTRACT=Abstract
Purpose: 18F labelled PSMA-1007 presents promising results in detecting prostate cancer (PC), while some pitfalls exists meanwhile. An intra-individual comparison of 18F-FDG and 18F-PSMA-1007 in patients with prostate cancer were aimed to be performed in the present study. Then the pitfalls of 18F-PSMA-1007 PET/CT in imaging of patients with prostate cancer were analyzed.
Methods and material: 21 prostate cancer patients underwent 18F-PSMA-1007 PET/CT as well as 18F-FDG PET/CT before surgery. All positive lesions were noticed and then differentiated PC metastasis from benign lesions. the SUVs, TBR of primary tumor, up to 10 metastases per patients were recorded (5 for bone, 5 for soft tissue metastasis ); the SUVs of up to 10 benign lesions per patients were recorded, too. Detection rate, SUVs and TBR of 18F-PSMA-1007 PET/CT and 18F-FDG PET/CT were compared for lesions, respectively. The optimal cut-off values of SUVs for metastases vs. benign lesions was found through areas under ROC in 18F-PSMA-1007.
Results: Detection rate of lesions (both primary and metastases) of 18F-PSMA-1007 PET/CT was higher than that of 18F-FDG PET/CT. The SUVs, TBR of primary tumor and metastases of 18F-PSMA-1007 PET/CT was higher than that of 18F-FDG PET/CT. 18F-PSMA-1007 PET/CT was more likely to detect benign lesions than 18F-FDG PET/CT. SUVs for metastases was significantly higher than for benign lesions in both 18F-PSMA-1007 PET/CT and 18F-FDG PET/CT. ROC suggested that SUVmax=7.71, SUVmean=5.35 might be the optimal cut-off values for metastases vs. benign lesions. No statistically significant difference was found when evaluating SUVmax of 18F-PSMA-1007 and 18F-FDG for benign lesions.
Conclusion: The pilot study suggested that 18F-PSMA-1007 showed superiority over 18F-FDG because its high detecting rate of PC lesions and excellent tumor uptake. While non-tumor uptake in 18F-PSMA-1007 may lead to misdiagnosis, recognizing these pitfalls and careful analysis can improve the accuracy of diagnosis.