ABSTRACT
PURPOSE: The aim of this study was to evaluate the detection rate of [68Ga]prostate-specific membrane antigen ([68Ga]PSMA-11) positron emission tomography (PET)/magnetic resonance imaging (MRI) and to compare it with [68Ga]PSMA-11 PET/X-ray computed tomography (CT) in patients with recurrent prostate cancer (PC) after radical prostatectomy. PROCEDURES: A total of 93 patients with biochemically recurrent prostate cancer underwent [68Ga]PSMA-11 PET/CT and subsequently a whole-body integrated PET/MRI examination. Board certified nuclear medicine physicians and radiologists evaluated PET/CT and PET/MRI datasets regarding identification of tumor lesions ((i) lymph nodes, (ii) bone lesions, (iii) local recurrence, and (iv) parenchymal lesions) based on maximum [68Ga]PSMA-11 uptake as well as morphological changes. Quality of PET images for both PET/CT and PET/MRI were rated using a 5-point scoring system by evaluating lesion homogeneity, contrast, contour, and delineation. Wilcoxon signed-rank tests were used to determine statistical differences. RESULTS: PC relapse was detected in 62/93 patients. PET/MRI detected 148 out of 150 lesions described in PET/CT. In addition, PET/MRI detected 11 lesions not detected in PET/CT (5 lymph nodes, 6 local recurrences). The exact McNemar statistical test (one-sided) showed significant difference between PET/CT and PET/MRI for diagnosis of local recurrence (p value = 0.031). Diagnostic confidence for (iii) was higher in PET/MRI compared with PET/CT (PET/CT = 1.1; PET/MRI = 4.9). Diagnostic confidence for (i) (PET/CT = 4.9; PET/MRI = 4.6), (ii) (PET/CT = 4.9; PET/MRI = 4.6), and (iv) (PET/CT = 4.6; PET/MRI = 4.8) was equivalent between PET/MRI and PET/CT. CONCLUSIONS: Integrated [68Ga]PSMA-11 PET/MRI provides a similarly high diagnostic performance for localization of recurrent PC as PET/CT. For the detection of local recurrences [68Ga]PSMA-11 PET/MRI is superior compared with [68Ga]PSMA-11 PET/CT.
Subject(s)
Antigens, Surface/metabolism , Edetic Acid/analogs & derivatives , Glutamate Carboxypeptidase II/metabolism , Magnetic Resonance Imaging/methods , Oligopeptides/pharmacokinetics , Positron Emission Tomography Computed Tomography/methods , Positron-Emission Tomography/methods , Prostatic Neoplasms/pathology , Whole Body Imaging/methods , Aged , Aged, 80 and over , Edetic Acid/chemistry , Edetic Acid/pharmacokinetics , Gallium Isotopes , Gallium Radioisotopes , Humans , Male , Middle Aged , Multimodal Imaging/methods , Neoplasm Recurrence, Local/diagnostic imaging , Neoplasm Recurrence, Local/metabolism , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/surgery , Oligopeptides/chemistry , Prostatectomy/methods , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/surgery , Radiopharmaceuticals/chemistry , Radiopharmaceuticals/pharmacokinetics , Reference Standards , Tissue DistributionABSTRACT
Integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) scanning has recently become established in clinical imaging. Various studies have demonstrated the great potential of this new hybrid imaging procedure for applications in the field of oncology and the diagnostics of inflammatory processes. With initial studies demonstrating the feasibility and high diagnostic potential of PET/MRI comparable to PET-computed tomography (CT), the focus of future studies should be on the identification of application fields with a potential diagnostic benefit of PET/MRI over other established diagnostic tools. Both MRI and PET/CT are widely used in the diagnostic algorithms for malignancies of the female pelvis. A simultaneous acquisition of PET and MRI data within a single examination provides complementary information which can be used for a more comprehensive evaluation of the primary tumor as well as for whole body staging. Therefore, the aim of this article is to outline potential clinical applications of integrated PET/MRI for the diagnostic work-up of primary or recurrent gynecological neoplasms of the female pelvis.