Using of 18 fluorine labeled prostatic specific membrane antigen positron emission tomography-computed tomography in staging of prostatic cancer in correlation with prostate specific antigen level

Abstract

Background: Due to its biological properties, Prostate-specific membrane antigen (PSMA) is a good target for prostate cancer molecular imaging. The aim of this work was to evaluate the role of 18F PSMA Tomography–Computed Tomography (PET CT) in the diagnosis and staging of cancer prostate in association with prostate specific antigen serum level. Methods: This prospective cohort work was performed on 30 individuals pathologically proven prostate cancer patients, seven patients were recently diagnosed and were referred for primary staging of the disease, and 27 patients were long term patients who received initial treatment and were referred due to high prostate-specific antigen (PSA) level. Results: There was positive association between PSA values and maximum standardized uptake values (SUV max) of PSMA expression at prostate with insignificant correlations between PSA and age or SUV max of PSMA expression of metastatic lesions of prostate cancer. At 3.4 cut-off value, SUV max of PSMA expression at prostate had 100% sensitivity and specificity win diagnosis of active local cancer prostatic lesions with higher AUC than PSA. PSA was higher among metastatic prostate cancer patients with statistically significant difference. At cut-off value equal to 5.3, PSA had 95% sensitivity and 71.4% specificity in prediction of metastasis.Conclusions: PSMA PET/CT is the modality of choice in recurrent cancer prostate, it can assess the site of recurrence and determine the disease burden. It can detect cancer prostate metastasis in non-enlarged lymph nodes, bony deposits even with no apparent CT morphological changes.