The Application Value of 18F Prostate-specific Membrane Antigen Positron Emission Tomography/Computerized Tomography（18F-PSMA-PET/CT）in Prostate Cancer
The Application Value of 18F Prostate-specific Membrane Antigen Positron Emission Tomography/Computerized Tomography（18F-PSMA-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, such as infection and
 bleeding. The American Urological Association (AUA) and the European Association of Urology
 (EAU) adopted that 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 correlation between patients' biochemical
 recurrence lesions and the PSA levels and Gleason score. There is a lack of research to
 explore the correlation among primary PCa burden, PSA levels, and the degree of prostate
 cancer malignancy. The aim of this project is to use 18F-PSMA PET/CT indexes SUVmax to
 analyze the correlation among primary PCa imaging, GS, and PSA levels, and to evaluate the
 predictive value of this method for prostate cancer risk stratification, metastasis risk, and
 biochemical recurrence.
Inclusion Criteria:

 -  1 age between 40 and 100 years old

 -  2 PSA >0.4 ng/mL for primary PCa with biopsy proven or RP diagnosis of prostate cancer

 -  3 PSA >0.2 ng/mL after RP, PSA ≥2 ng/mL above the nadir after EBRT) or persisting PSA
 after radical treatment with rising PSA values

 -  4 complete clinical, pathological, imaging and biochemical information

 Exclusion Criteria:

 -  1 lack of histological examinationproven diagnosis of PCa

 -  2 18F-PSMA PET/CT being performed after pharmacotherapy since PSMA-targeted imaging
 can be disturbed by previous therapie