The pharmacokinetics of 68Ga-PSMA-11 leads to intense bladder accumulation, obscuring adjacent lesions. This study evaluated the feasibility of dynamic whole-body 68Ga-PSMA-11 PET/CT Patlak parametric imaging to reduce bladder signal interference, and compared the difference between the long axial field of view (LAFOV) PET/CT and short axial field of view (SAFOV) PET/CT. A total of 18 patients with prostate cancer were prospectively enrolled in this study, 9 patients were scanned on the uMI Panorama GS (FOV = 148 cm), and the other 9 patients were scanned on the uMI Panorama 35 C (FOV = 35 cm). The V images demonstrated a significant reduction in bladder TBR LAFOV: TBRSUV: 26. 71 (14. 50-34. 83) vs. TBRV: 0, P < 0. 001; SAFOV: TBRSUV: 14. 56 (12. 64–17. 97) vs. TBRV: 0. 08 (0-1. 42), P < 0. 001 and SV LAFOV: TBRSUV: 154. 06 ± 86. 64 cm3 vs. SVV: 0. 94 ± 2. 83 cm3, P < 0. 001; SAFOV: SVSUV: 174. 33 ± 95. 48 cm3 vs. SVV: 12. 90 ± 11. 41 cm3, P < 0. 001, achieving a 99. 5% and 91. 0% volume reduction in LAFOV and SAFOV PET, respectively. Prostatic base obscuration occurred in 33. 3% (3 + 3/18) of SUV images (score = 2) but was absent in V images. All primary prostate lesions (15/15) and 96. 7% (58/60) metastases were detected on V images in LAFOV PET. All primary prostate lesions (10/10) and 90. 9% (20/22) metastases were detected on V images in SAFOV PET. In LAFOV PET, whether it is a primary or metastatic lesion, TBRSUV is higher than TBRV, but lower than TBRKi, all of which differ significantly. In SAFOV PET, lymph node metastases exhibited higher, while bone metastases showed no significant TBR difference, and primary prostate TBRV was lower than TBRSUV but remained above background. Compared with SAFOV PET, TBRSUV, TBRV, TBRKi of LAFOV PET were significantly higher (all P < 0. 01). Patlak V imaging significantly reduces bladder signal intensity and obscuration in 68Ga-PSMA-11 PET/CT while preserving lesion TBR, enabling improved visualization of prostatic base lesions. Whether LAFOV or SAFOV PET, dynamic whole-body Patlak parametric imaging is feasible for mitigating bladder interference. Our results indicate that parametric imaging contributes to improved clinical evaluation of prostate cancer lesions.
Zuo et al. (Sat,) studied this question.