PET Imaging in Primary Diagnosis of Prostate Cancer

Dr. Oyen discussed the evolving role of PET imaging in the primary diagnosis of prostate cancer at EAU PCa 2018. Multiple PET tracers exist, including choline, Fluciclovine (F-18-FACBC), PSMA (with multiple subtypes), F-18-FDHT, FDG, diphosphonate bone scan, and Na-F-18. Each has distinct properties and clinical applications, particularly in staging lymph nodes and metastases.

Choline PET/CT has good specificity (92%) but limited sensitivity (62%) for lymph node metastases. While it can guide management in 20–25% of metastatic cases, its accuracy is insufficient to replace nodal dissection. Low PSA levels and slow-growing tumors reduce its detection rate. Fluciclovine, a synthetic amino acid analog, has favorable biodistribution with minimal urinary tract uptake, improving detection in low-PSA patients and recurrent disease.

PSMA PET/CT is currently considered the most promising tracer, offering rapid clearance, high targeting, and detection of lesions as small as 4 mm. However, it cannot reliably detect micrometastases, and PSMA expression occurs in other cancers. Despite advancements, it remains unclear whether earlier detection of small-volume disease improves long-term outcomes. Large-scale randomized studies are unlikely, leaving ongoing questions about the optimal use of PET imaging in primary prostate cancer diagnosis.

For male patients, these imaging modalities represent a growing set of tools to better detect and stage prostate cancer, potentially guiding treatment more precisely while highlighting limitations in sensitivity, especially for small or early lesions.

Goldberg, H. (2018, September 14–15). EAU PCa 2018: Is there a place for PET scanning in the primary diagnosis of prostate cancer? UroToday. https://www.urotoday.com/conference-highlights/pca18/106908-eau-pca-2018-is-there-a-place-for-pet-scanning-in-the-primary-diagnosis-of-prostate-cancer.html