The usefulness of FCH Positron Emission Tomography–Computed Tomography (PET/CT) in the localisation of PCa foci in patients with rising serum PSA level after treatment has been extensively documented [3, 7–10] and FCH PET/CT can also be helpful in guiding salvage radiation therapy [11, 12]. Here, KLK3 is linked to posterior cortical atrophy.