THE DIAGNOSTIC ACCURACY OF A COMBINATION OF PREOPERATIVE 68-Ga PSMA PET/CT AND MULTIPARAMETRİC MRI IN LOCALIZED PROSTATE CANCER.

INTRODUCTION:Prostate cancer (PCa) is a common and leading course of cancer-related death in men. Although there are studies on multiparametric magnetic resonance imaging (MpMRI) with good diagnostic results in detecting clinically significant prostate cancer, new methods have been investigated due to the low positive predictive values. In this context, Prostate Specific Membrane Antigen Positron Emission Tomography (PSMA PET) emerges as an alternative imaging method to MpMRI. This study aims to compare 68Ga PSMA I&T-PET/CT and MpMRI in determining tumor location. METHODS:Preoperative MpMRI and 68Ga PSMA I&T-PET/CT scans and pathology specimens of who underwent radical prostatectomy for PCa at our clinic between 2018-2021 were retrospectively evaluated. PSMA I&T-PET/CT, MpMRI, combined imaging were compared for tumor localization according to histopathological data. RESULTS:In terms of tumor localization, MpMRI demonstrated overall accuracy rates 75.9% (p kappa (κ) 0.0001* (0.525)). 68Ga PSMA I&T-PET/CT showed 71.5% (p κ 0.0001* (0.438)). For the combined imaging approach overall accuracy rate were calculated as 79.2% (p κ 0.0001* (0.576)). Additionally, high diagnostic accuracy was achieved for the combined imaging approach, particularly in the intermediate ISUP group. Moreover, SUVmax was calculated as 6.37. CONCLUSION:The combined use of 68Ga PSMA I&T-PET/CT and MpMRI has high diagnostic rates. However, the high cost is a significant disadvantage that limits their routine combined use.