At PSA below 0.5 ng/mL, detection rates range between 38% and 64% [2, 6, 7], indicating that the approved PSMA radioligands will fail to localize the site of PCa recurrence in 1/3rd to 2/3rd of patients with PSA below 0.5 ng/mL. This evidence concerns the gene FOLH1 and posterior cortical atrophy.