Author/Authors :
Flechsig, Paul Department of Nuclear Medicine - University Hospital Heidelberg - Heidelberg, Germany , Zabeck, Heike Thorax Clinic at Heidelberg University - Division of Thoracic Surgery - Heidelberg, Germany , Reubold, Sebastian Department of Nuclear Medicine - University Hospital Heidelberg - Heidelberg, Germany , Sachpekidis, Christos Department of Nuclear Medicine - University Hospital Heidelberg - Heidelberg, Germany , Rathke, Hendrik Department of Nuclear Medicine - University Hospital Heidelberg - Heidelberg, Germany , Röhrich, Manuel Department of Nuclear Medicine - University Hospital Heidelberg - Heidelberg, Germany , Holland-Letz, Tim Department of Biostatistics - German Cancer Research Center - Heidelberg, Germany , Heussel, Claus-Peter Thorax Clinic at Heidelberg University - Division of Diagnostic and Interventional Radiology with Nuclear Medicine - Heidelberg, Germany , Harms, Alexander Institute of Pathology - University Hospital Heidelberg - Heidelberg, Germany , Kauczor, Hans-Ulrich Translational Lung Research Center Heidelberg - German Center for Lung Research - Heidelberg, Germany , Haberkorn, Uwe Department of Nuclear Medicine - University Hospital Heidelberg - Heidelberg, Germany , Giesel, Frederik L Department of Nuclear Medicine - University Hospital Heidelberg - Heidelberg, Germany
Abstract :
Background: Regarding mediastinal N-staging in lung cancer patients, computed tomography (CT), magnetic resonance imaging
(MRI), and integrated 18Fluorine-fluorodeoxyglucose-positron emission tomography/CT (18F-FDG-PET/CT) are the most widespread
imaging methodologies in clinical routine.
Objectives: In order to further extract information from non-invasive staging, we evaluated the use of 18F-FDG-PET/CT and dynamic
contrast enhanced (DCE) and diffusion-weighted imaging (DWI) MRI using histopathology as the diagnostic gold standard.
Patients and Methods: A total number of 50 patients had undergone MRI of the chest within two weeks prior to surgery for
histopathological proof. DCE-MRI was evaluated on the basis of region of interest (ROI)-based signal intensity/time (SI/T) curves in
the respective mediastinal lymph nodes (LNs). In total, 28 LNs could be allocated to the corresponding histopathological findings,
as well as to corresponding findings in 18F-FDG-PET/CT.
Results: Malignant LNs presented with significantly higher FDG uptake in PET. Significant differences between malignant and benign
LNs were found for DCE-MRI regarding the parameters MaxE, 4-minutes value, SE, EP and EP/MaxE. In DWI-MRI, malignant LNs
presented with significantly lower signal intensity compared to benign LNs (p < 0.01). An apparent diffusion coefficient (ADC)
threshold of 1528mm2/s was found to exclude malignancy for LNs that are above the threshold.
Conclusion: 18F-FDG-PET in addition with MRI that includes DWI might improve mediastinal N-staging, which is of interest in cases
of FDG-equivocal LNs. An ADC threshold of 1528 mm2/s might potentially help to further classify LNs with indefinite PET-findings.
DCE-MRI of mediastinal LNs seems not yet to be approved for clinical routine.
Keywords :
Lung Cancer , staging , FDG-PET/CT , Magnetic Resonance Imaging , DWI
