18F-PSMA PET/CT Versus CT Alone in Assessment of Prostatic Cancer Patients

Prostate cancer represents the most frequently diagnosed malignancy in men worldwide and accounts for approximately 30% of all new male cancer diagnoses in 2025, with recent data highlighting a significant 3% annual increase in incidence rates, particularly in advanced-stage disease\[1\]. The accurate staging and restaging of prostate cancer (PCa) are critical for determining the optimal therapeutic approach, particularly in detecting nodal or distant metastases \[2\]. The Gleason score and Prostate-Specific Antigen (PSA) levels serve as the foundational pillars for the clinical staging and initial risk stratification of prostate cancer. The Gleason score, which evaluates the histological architecture and cellular differentiation of prostate tissue from a biopsy, is calculated by summing the two most prevalent cancer patterns (yielding scores typically ranging from 6 to 10) \[3\]. Concurrently, the serum PSA level acts as a biochemical marker reflecting the overall volume and activity of the prostatic disease \[3,4\]. Computed Tomography (CT) has been the standard imaging modality for assessment of metastatic sites; however, it relies primarily on anatomy, such as lymph node size and shape, which often leads to low sensitivity in detecting early-stage or micrometastatic disease\[5\]. Recently, in response to these limitations the landscape has shifted toward molecular imaging with PSMA-targeted imaging using PET/CT which targets the Prostate-Specific Membrane Antigen (PSMA) -a protein significantly overexpressed in malignant prostate cells-allowing for the detection of lesions independent of their anatomical size \[6\]. Evidence suggests that PSMA PET/CT provides superior diagnostic accuracy, higher sensitivity, and better specificity compared to CT alone, often leading to a change in clinical management for a substantial percentage of patients\[2,7\]. Additionally, the clinical utility of 18-F PSMA PET/CT is significantly enhanced by its capacity for calculating quantitative analysis. Metrics such as the maximum Standardized Uptake Value (SUVmax), PSMA-derived tumor volume (PSMA-TV), and total lesion PSMA (TL-PSMA) provide an objective, reproducible assessment of disease burden \[8\]. In this study, we aim to compare the diagnostic performance of 18-F PSMA PET/CT and CT alone in staging, assessment of therapy response, as well as evaluation of biochemical recurrence

• Correlation between quantitative measures and other clinical, pathological and laboratory measures [Time frame: 2 years]