E5323. Efficacy of Forced Diuresis and Scan Timing in Reduction of Urinary Activity-Related Artefact on PSMA PET/CT: A Systematic Review
  1. Seyedeh Niloufar Rafiei Alavi; University of California, Irvine
  2. Shawn Sun; University of California, Irvine
  3. James Shi-; ; University of California, Irvine
  4. Mark Tran; University of California, Irvine
  5. Vahid Yaghmai; University of California, Irvine
PSMA has strong potential for prostate cancer diagnosis and prognosis, but challenges persist in accurately assessing local recurrence and pelvic lymph nodes due to urinary tracer accumulation. Different methods aim to address this, but a consensus on the best approach is lacking. This study conducts a systematic review to fill this gap and reach informed conclusions.

Materials and Methods:
In this comprehensive systematic review, an extensive search encompassing multiple electronic medical databases was undertaken to identify pertinent studies investigating techniques and protocol modifications of PSMA PET imaging aimed at reducing urinary tracer accumulation. A total of 15 studies were included. The studies were categorized into three intervention types: A) forced diuresis (via furosemide), B) early dynamic imaging, and C) additional late imaging. Study characteristics were summarized. Outcomes and results were synthesized and compared across the studies.

Among the studies, seven explored forced diuresis using Furosemide injection, which reduced urinary activity, minimized artifacts, and improved recurrence detection. Four studies introduced an early dynamic/static phase at 5-6 minutes, crucial for prostate lesion visibility before tracer accumulation. Five studies used a late PSMA PET phase at 120 minutes, enhancing recurrence detection and distinguishing benign from malignant lymph nodes. Heterogeneity exists among methods, requiring further research to identify suitable patient populations. Tailoring interventions to clinical contexts is crucial. Diuretics can mitigate bladder activity, but not for certain patients (e.g., with CKD). Early/late phases benefit different cases. A combination of dynamic early (1 hour) and delayed (2 hours) imaging suits staging, recurrence, and lesion characterization; delayed imaging is more beneficial for whole body metastatic assessment.

The findings of this study underscore the complexity of optimizing PSMA PET imaging protocols. The nuances of patient profiles and clinical goals should guide the choice of intervention. This tailored approach has the potential to significantly improve the accuracy and reliability of PSMA PET imaging in prostate cancer diagnosis and management, enhancing the overall quality of patient care.