The Application Value of 18F-prostate-specific Membrane Antigen PET/CT in Prostate Cancer

Prostate cancer (PCa) is the most common type of malignant tumor and the third leading cause of cancer-associated mortality among men worldwide. The biological behaviors of PCa at different degrees of malignancy also largely differ, directly impacting disease outcomes and responses to treatment. Therefore, accurate risk stratification of PCa before treatment and the development of an individualized treatment regimen, play a vital role to improve the clinical outcome of patients. However, overdiagnosis and unnecessary biopsies, which are invasive examinations associated with higher costs and adverse effects. When the PSA is less than 20ng/mL, less than 1% of PCa patients have a positive bone scan, and routine bone scans are not recommended for asymptomatic or low-risk PCa patients. Interestingly, due to the variations among evaluators that often occur when defining the T stage, biopsies operate inaccuracy, also low-PSA level can also occur metastasis, there is a need for an objective and accurate imaging biomarker for the diagnosis of different grade PCa. Prostate-specific membrane antigen (PSMA) is a type II transmembrane protein, which has higher expression in cancerous prostate cells than in normal prostate cells. Meanwhile, its expression level is positively correlated with the degree of malignancy, the tendency of metastasis, and the risk of early recurrence. In recent years, 18F-PSMA positron emission tomography/computerized tomography (PSMA PET/CT) has earned widespread attention as a novel imaging modality based on molecular-level analysis, rather than morphological or physiological analysis, to assist in PCa diagnosis and tumor burden evaluation. Currently, Maximum Standardized Uptake Value (SUVmax) is the most commonly used semi-quantitative parameter in PET/CT, which is used to assess tumor burden of PCa, and thus can be used as an imaging biomarker to assess the degree of malignancy of prostate cancers. However, prior studies mainly focused on the corre