KLK3 and posterior cortical atrophy: Compared with conventional PCa detection methods, such as digital rectal examination (DRE), PSA, ultrasonic imaging, and MP-MRI, targeted molecular imaging using radionuclide-labeled drugs provides not only anatomical information but also molecular, metabolic information on the whole-body scale and includes positron emission tomography/computed tomography (PET/CT) and single-photon emission computed tomography/computed tomography (SPECT/CT) (Vargas et al., 2015; Wibmer et al., 2016).