Diagnostic Possibilities of PET/CT with 18F-PSMA in Patients with Suspected Prostate Cancer

Relevance. Prostate cancer (PC) is one of the most common malignant neoplasms in men. Every year, about 1.4 million new cases of prostate cancer are diagnosed in the world and 366,000 men die each year from this pathology. Despite the presence of a fairly wide range of diagnostic options in the early diagnosis of prostate cancer, primarily the determination of the level of prostate specific antigen (PSA) in the blood serum and multiparametric magnetic resonance imaging (mpMRI), there remains a group of patients with ambiguous values of the above indicators. The use of positron emission tomography combined with computed tomography (PET/CT) with a tumoritropic radiopharmaceutical drug (RFLP) 18F-PSMA improves the early diagnosis of prostate cancer, which is the key to success for successful treatment, duration and quality of life of the patient. Material and methods. The study included 30 patients with suspected prostate cancer, based on the PSA level in the ʽgray zoneʼ 2–10 ng/ml and Pi-RADS 3 according to the MRI data. All patients underwent PET/CT with 18F-PSMA, with further morphological verification of the process. Results. Out of 30 patients, 7 (23.33%) had positive PET/CT with 18F-PSMA. The diagnostic model obtained during the construction and subsequent analysis of the SUV level ROC-curve showed high values of sensitivity (86%), specificity (100%), diagnostic accuracy (86%) and positive predictive value (100%) of the method (area under ROC-curve (AUC) 0.93), with reference indicators of RFLP accumulation – standardized uptake value (SUV) 2.5. The negative predictive value was 27%. Conclusion. Our study confirmed the high diagnostic accuracy of PET/CT with 18F-PSMA in the differential diagnosis of a tumor process in the prostate gland, with a reference indicator SUV > 2.5. We recommend 18F-PSMA PET/CT in patients with suspected PCa who have ambiguous PSA (2-10 ng/mL) and mpMRI (Pi-RADS 3) findings.