KLK3 and metastatic malignant neoplasm in the lymph nodes: Although [18F]choline and [18F]fluciclovine PET examinations have higher sensitivity (up to 90%) and specificity (up to 100%) than bone scans for finding bone metastases in patients with BCR [31,32], sensitivity of both these tracers is highly dependent on the PSA level and is less than 50% at PSA lower than 1.0 ng/mL [33], with poorer sensitivity of [18F]choline for detecting lymph node metastases than [18F]fluciclovine PET scan.