The goal of this prospective, single-center, single-arm trial is to evaluate the positive predictive values between 18F-PSMA-1007 PET/CT based on diagnostic model in patients with suspicious of prostate cancer. The main question and our aim to answer is:

• Can these patients with clinically significant prostate cancer in 18F-PSMA-1007 PET/CT based on diagnostic model undergo radical prostatectomy directly without prostate biopsy.

Participants will be asked to accomplish the test of serum PSA, mpMRI, then, the eligible patients (The probability of the diagnostic model to predict clinically significant prostate cancer was greater than or equal to 60 percent) need perform 18F-PSMA-1007 PET/CT. Finally, patients will receive radical prostatectomy directly if prostate cancer is considered by 18F-PSMA-1007 PET/CT.

Study Design and Setting SNOTOB study is a prospective, single-center, single-arm and open-label clinical study and conducted in the First Affiliated Hospital of USTC in China. Patients who have no surgical contraindications and meet the enrollment criteria will be recruited to the study. Subsequently, we will recommend these patients to accept radical prostatectomy without prostate biopsy directly. Before the operation, patients and their family member will be fully informed of the surgical risks, the necessity to perform a prostate biopsy for pathologic confirmation, the possibility of benign prostatic disease and the other alternative therapeutic methods including active surveillance, radiotherapy, and focal therapies and so on. Finally, the diagnostic performance of our noninvasive diagnostic strategy will be verified with the pathological results.

Screening and Enrollment The noninvasive diagnostic strategy in this study consists of a prostate cancer diagnostic model and 18F-prostate-specific membrane antigen-1007 positron emission tomography/computed tomography (18F-PSMA-1007 PET/CT) examination in series. After the patients complete the serum prostate-specific antigen (PSA) test and multiparameter magnetic resonance imaging (mpMRI), we can obtain the information of prostate-specific antigen density (PSAD) and prostate imaging-reporting and data system version 2.1 (PI-RADS v2.1) score. Then, patients' risk probability of clinically significant prostate cancer (csPCa) will be calculated by the online diagnostic nomogram (website: https://ustcprostatecancerprediction.shinyapps.io/dynnomapp/). When the prediction probability of csPCa is equal or greater than 0.60, 18F-PSMA-1007 PET/CT will be applied for further diagnosis. If patients are still considered as csPCa after 18F-PSMA-1007 PET/CT examinations, we define this condition as positive result of our noninvasive diagnostic strategy. These patients meet our criteria of this study. Of note, patients with prediction probability less than 0.60 will no longer undergo 18F-PSMA-1007 PET/CT examinations, and patients with risk probability equal or greater than 0.60 but negative 18F-PSMA-1007 PET/CT examinations will not meet the enrollment criteria too.

Inclusion Criteria:

1. Men with clinically suspected prostate cancer (abnormal DRE or PSA);
2. Complete the test of serum PSA and examination of mpMRI;
3. 4 ng/ml ≤serum total PSA<100ng/ml;
4. The probability of the diagnostic model to predict clinically significant prostate cancer was greater than or equal to 60 percent;
5. Prostate cancer is considered by 18F-PSMA-1007 PET/CT;
6. Meet the surgical indications for radical prostatectomy.

Exclusion Criteria:

1. Incomplete information of serum PSA tests or mpMRI;
2. serum total PSA<4ng/ml or ≥ 100 ng/ml;
3. The probability of the diagnostic model to predict clinically significant prostate cancer was less than 60 percent;
4. Prostate cancer is not considered by 18F-PSMA-1007 PET/CT;
5. Patients who have negative results in the previous prostate biopsy;
6. Patients refuse radical prostatectomy or still choose prostate biopsy.