Diagnostic value of dual-time point 68Ga-PSMA PET/CT image for benign and malignant lesions in patients with prostate cancer

Liu Xiao; Minggang Su; Yuhao Li

doi:10.1007/s00261-024-04269-w

Diagnostic value of dual-time point ⁶⁸Ga-PSMA PET/CT image for benign and malignant lesions in patients with prostate cancer

Abdom Radiol (NY). 2024 Mar 28. doi: 10.1007/s00261-024-04269-w. Online ahead of print.

Authors

Liu Xiao¹, Minggang Su¹, Yuhao Li²

Affiliations

¹ Department of Nuclear Medicine, West China Hospital of Sichuan University, No. 37. Guoxue Alley, Chengdu, 610041, Sichuan, People's Republic of China.
² Department of Nuclear Medicine, West China Hospital of Sichuan University, No. 37. Guoxue Alley, Chengdu, 610041, Sichuan, People's Republic of China. tsflyh@126.com.

PMID: 38546825
DOI: 10.1007/s00261-024-04269-w

Abstract

Objective: This study aimed to ascertain the diagnostic efficacy of routine ⁶⁸Ga-PSMA imaging conducted 1 h post-injection, in conjunction with delayed imaging performed 3 h post-injection, for differentiating between benign and malignant lesions in prostate cancer (PCa) patients.

Methods: A retrospective assessment was undertaken on 44 prostate cancer patients who had undergone both routine and delayed ⁶⁸Ga-PSMA PET/CT scans. Variations in SUVmax and SUVmean values in normal organs, primary prostate cancer sites, metastatic sites, and benign lesions were analyzed. Pathological examination and extended follow-ups were used to confirm all lesions.

Results: The study encompassed 44 patients, presenting 35 primary prostate cancer lesions, 44 metastatic lesions, and 30 benign lesions. Delayed imaging (3 h post-injection) demonstrated a decreasing trend in the SUVmax and SUVmean for the liver, blood, and spleen. Conversely, an increasing trend was observed for the parotid, lacrimal, and submandibular glands. For primary lesions, the SUVmax and SUVmean values were 17.63 ± 9.61 and 9.77 ± 5.18 during routine imaging, and 25.09 ± 15.11 and 14.05 ± 8.02 (P < 0.001) during delayed imaging. A comparable increase in SUVmax and SUVmean was seen in the delayed images for metastatic lesions when juxtaposed with routine images. Nevertheless, benign lesions displayed a decrease in SUVmax and SUVmean during delayed imaging when set against routine imaging (SUVmax: 3.56 ± 1.49 vs 2.93 ± 1.47, P = 0.001; SUVmean: 1.99 ± 0.87 vs 1.65 ± 0.87, P = 0.003).

Conclusion: Imaging using ⁶⁸Ga-PSMA PET/CT at 3 h post-injection manifested a higher uptake and target-to-background uptake in most malignant prostate cancer lesions, but a diminished uptake in benign lesions. This observation can assist clinicians in distinguishing non-specific PSMA uptake in prostate cancer patients based on PSMA PET/CT image.

Keywords: Delay image; PSMA PET/CT; Prostate cancer; SUV.