Recent evidence suggests that both standard-time and delayed-time \[⁶⁸Ga\]Ga-PSMA PET acquisitions can reveal clinically relevant findings, and neither phase should be excluded a priori in routine practice. This study evaluates a streamlined dual-phase protocol consisting of:
* A standard whole-body PET/CT acquisition performed 60 minutes after radiotracer administration. * A delayed pelvic PET-only acquisition performed 90 minutes post-injection, reconstructed using the attenuation-correction CT (CT/AC) obtained from the initial whole-body scan.
Because the prostate gland and pelvic lymph nodes exhibit minimal physiological mobility, accurate PET-CT anatomical correspondence can be maintained through careful patient repositioning, without repeating the CT scan.
The main advantage of this protocol is a reduction in patient radiation exposure, as the delayed phase does not require a second CT scan. It also reduces in-department time and maintains diagnostic quality of PET interpretation, provided that the PET-CT alignment remains acceptable.
This method may additionally enhance workflow efficiency in the Nuclear Medicine Unit by allowing early identification-based on predefined clinical parameters-of patients most likely to benefit from delayed pelvic imaging.
Newly diagnosed prostate cancer undergoing staging, or
Biochemical recurrence following prior radical-intent therapy (surgery and/or radiotherapy), or
High-risk prostate cancer, defined as Gleason Score ≥ 8 or PSA ≥ 20 ng/mL.
Written informed consent and authorization for personal data processing.
Genitourinary comorbidities that could interfere with imaging or interpretation.
Intermediate- or low-risk prostate cancer.
Delayed acquisition performed on a PET/CT scanner different from the standard acquisition.
Additional PET/CT required due to artifacts compromising diagnostic quality (e.g., urinary retention, excessive motion).