68Ga-PSMA-11 PET/MR Can Be False Positive in Normal Prostatic Tissue

Area of Science:

• Oncology
• Nuclear Medicine
• Radiology

Background:

• Prostate-specific membrane antigen (PSMA) is a key biomarker for prostate cancer.
• Ga-PSMA-11 PET/MR is a valuable imaging modality for detecting prostate cancer.
• PSMA expression is typically high in prostate cancer cells.

Observation:

• A 65-year-old man presented with two focal PSMA-positive areas on Ga-PSMA-11 PET/MR.
• One PSMA-positive area corresponded to a confirmed prostate carcinoma (Gleason score 4 + 3).
• The second PSMA-positive area showed no evidence of malignancy but high PSMA expression via immunohistochemistry.

Findings:

• Ga-PSMA-11 PET/MR identified distinct PSMA-avid regions within the prostate.
• The study highlights a case where PSMA expression was elevated in a non-malignant prostate region.
• Immunohistochemistry confirmed high PSMA expression in both the cancerous and non-cancerous lesions.

Implications:

• This case suggests that PSMA expression may not always correlate directly with malignancy in all prostate regions.
• Further research is needed to understand the biological basis of PSMA expression in non-cancerous prostate tissue.
• The findings may refine the interpretation of PSMA-PET imaging in prostate cancer diagnosis and management.