KLK3 and posterior cortical atrophy: In detecting bone metastases at initial diagnosis of PCa, bone scintigraphy presents a relatively low diagnostic yield of 3.5% with PSA ≤ 10 ng/mL, 6.9% with PSA between 10 and 20 ng/mL, and 41.8% with PSA > 20 ng/mL [1].