PSA Zero Radiographic Disease Progression on PSMA PET/CT

Area of Science:

• Oncology
• Nuclear Medicine
• Radiology

Background:

• Prostate cancer (PCa) progression can occur despite undetectable prostate-specific antigen (PSA) levels.
• Radiographic disease progression (rDP) in PCa requires further investigation, especially in the context of low PSA.
• The utility of PSMA PET/CT in identifying rDP with undetectable PSA needs clarification.

Purpose of the Study:

• To determine the frequency and characteristics of radiographic disease progression (rDP) on PSMA PET/CT in prostate cancer (PCa) patients with undetectable PSA levels.
• To analyze the clinical implications of PSA zero rDP, including progression to castration-resistant PCa and overall survival.
• To evaluate the association between sites of rDP and overall survival (OS).

Main Methods:

• Analysis of the Mayo Clinic PSMA PET Prostate Cancer Registry for patients with rDP and undetectable PSA.
• Confirmation of disease progression via biopsy or treatment response.
• Estimation of overall survival (OS) using Kaplan-Meier method and log-rank test for group comparisons.

Main Results:

• 12% (257/2141) of patients exhibited PSA zero rDP between 2021-2023.
• 61% had initially localized disease, 39% had de novo metastatic disease.
• Visceral metastases were significantly associated with poorer OS (p < 0.0001).

Conclusions:

• Prostate cancer patients frequently develop metastatic disease even with undetectable PSA values.
• Periodic advanced imaging, such as PSMA PET/CT, is recommended irrespective of PSA levels for timely detection of progression.
• Early detection through advanced imaging facilitates prompt management of PCa progression.