Abstract
BackgroundThe purpose of this study was to investigate the imaging properties of pulmonary metastases and benign opacities in 68Ga-PSMA positron emission tomography (PET) in patients with prostate cancer (PC).Methods68Ga-PSMA-PET/CT scans of 739 PC patients available in our database were evaluated retrospectively for lung metastases and non-solid focal pulmonary opacities. Maximum standardized uptake values (SUVmax) were assessed by two- and three-dimensional regions of interest (2D/3D ROI). Additionally CT features of the lesions, such as location, morphology and size were identified.ResultsNinety-one pulmonary metastases and fourteen opacities were identified in 34 PC patients. In total, 66 PSMA-positive (72.5%) and 25 PSMA-negative (27.5%) metastases were identified. The mean SUVmax of pulmonary opacities was 2.2±0.7 in 2D ROI and 2.4±0.8 in 3D ROI. The mean SUVmax of PSMA-positive pulmonary metastases was 4.5±2.7 in 2D ROI and in 4.7±2.9 in 3D ROI; this was significantly higher than the SUVmax of pulmonary opacities in both 2D and 3D ROI (p<0.001). The mean SUVmax of PSMA-negative metastases was 1.0±0.5 in 2D ROI and 1.0±0.4 in 3D ROI, and significantly lower than that of the pulmonary opacities (p<0.001). A significant (p<0.05) weak linear correlation between size and 3D SUVmax in lung metastases (ρSpearman=0.207) was found.ConclusionBased on the SUVmax in 68Ga-PSMA-PET alone, it was not possible to differentiate between pulmonary metastases and pulmonary opacities. The majority of lung metastases highly overexpressed PSMA, while a relevant number of metastases were PSMA-negative. Pulmonary opacities demonstrated a moderate tracer uptake, significantly lower than PSMA-positive lung metastases, yet significantly higher than PSMA-negative metastases.
Highlights
The purpose of this study was to investigate the imaging properties of pulmonary metastases and benign opacities in 68Ga-prostate-specific membrane antigen (PSMA) positron emission tomography (PET) in patients with prostate cancer (PC)
Based on the SUVmax in 68Ga-PSMA-PET alone, it was not possible to differentiate between pulmonary metastases and pulmonary opacities
68Ga-PSMA-Positron emission tomography / computed tomography (PET/CT) for the assessment of lung metastases Our study demonstrates that, a majority of PC lung metastases were PSMA-positive, a considerable share of metastases was PSMA-negative and could not be detected directly by 68Ga-PSMA-PET
Summary
The purpose of this study was to investigate the imaging properties of pulmonary metastases and benign opacities in 68Ga-PSMA positron emission tomography (PET) in patients with prostate cancer (PC). Methods: 68Ga-PSMA-PET/CT scans of 739 PC patients available in our database were evaluated retrospectively for lung metastases and non-solid focal pulmonary opacities. Radiolabeled prostate-specific membrane antigen (PSMA) ligands such as 68Ga-PSMAHBED-CC have been introduced recently as promising radiotracers for the PET imaging of PC [2]. Different studies have demonstrated the Damjanovic et al Cancer Imaging (2018) 18:20. Pulmonary metastases are considered to be the second most common extranodal metastases in PC (46%), after bone metastases (90%) [17]. The clinical incidence of PC pulmonary metastases in a large retrospective review study has been 3.6% [18]. The data suggest that the presence of pulmonary metastases has no ominous impact on clinical course and disease outcome [19], early and reliable detection of lung metastases can be of high clinical importance for accurate staging and therapy planning
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
