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.