INTRODUCTION
Prostate cancer is the most common cancer in men according to the Global Burden of Cancer (GLOBOCAN) 2018 data. In cancer-related deaths, it takes second place after lung cancer [1]. Multiparametric magnetic resonance imaging (mpMRI) is defined as the addition of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced imaging (DCI) to classical T2-weighted MRI examination, which is used for diagnosis and local staging in prostate cancer. The Prostate Imaging- Reporting and Data System (PI-RADS) assessment uses a 5-point scale based on the probability that a combination of mpMRI findings at T2-weighted imaging, DWI, and DCI to identify the each lesion in the prostate. While mpMRI has become the standard approach after prior negative biopsy [2], some prostate cancer lesions may be overlooked [3,4]. Therefore, there is clearly still a demand for improved imaging methods to more accurately identify prostate cancer.
Hybrid positron emission tomography (PET) / MRI devices, which clinicians have recently started to use, combine the functional findings of PET with the high tissue contrast of mpMRI and increase the intraprostatic lesion detection rates significantly [5]. Several radiopharmaceuticals including 18Fluorine (18F) -ethyl choline, 11Carbon (11C) -Acetate, 18F- Fluorodeoxyglucose (FDG), fluorocyclobutanecarboxylic acid (FACBC) that have shown promise in prostate cancer imaging have been recently put into use. However, 68Gallium – prostate membrane specific antigen (68Ga-PSMA) is currently the most widely used radiopharmaceutical in PET diagnostic imaging for prostate cancer [6].
The aim of our study is to evaluate the diagnostic accuracy of the68Ga-PSMA PET/MRI and mpMRI by region-based comparison of index tumour localisations using histopathological tumour maps of patients who underwent radical prostatectomy (RP) due to clinically significant prostate cancer.