@article{LapaReiterKircheretal.2016, author = {Lapa, Constantin and Reiter, Theresa and Kircher, Malte and Schirbel, Andreas and Werner, Rudolf A. and Pelzer, Theo and Pizarro, Carmen and Skowasch, Dirk and Thomas, Lena and Schlesinger-Irsch, Ulrike and Thomas, Daniel and Bundschuh, Ralph A. and Bauer, Wolfgang R. and Gartner, Florian C.}, title = {Somatostatin receptor based PET/CT in patients with the suspicion of cardiac sarcoidosis: an initial comparison to cardiac MRI}, series = {Oncotarget}, volume = {7}, journal = {Oncotarget}, number = {47}, doi = {10.18632/oncotarget.12799}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175423}, pages = {77807-77814}, year = {2016}, abstract = {Diagnosis of cardiac sarcoidosis is often challenging. Whereas cardiac magnetic resonance imaging (CMR) and positron emission tomography/computed tomography (PET/CT) with \(^{18}\)F-fluorodeoxyglucose (FDG) are most commonly used to evaluate patients, PET/CT using radiolabeled somatostatin receptor (SSTR) ligands for visualization of inflammation might represent a more specific alternative. This study aimed to investigate the feasibility of SSTR-PET/CT for detecting cardiac sarcoidosis in comparison to CMR. 15 patients (6 males, 9 females) with sarcoidosis and suspicion on cardiac involvement underwent SSTR-PET/CT imaging and CMR. Images were visually scored. The AHA 17-segment model of the left myocardium was used for localization and comparison of inflamed myocardium for both imaging modalities. In semi-quantitative analysis, mean (SUV\(_{mean}\)) and maximum standardized uptake values (SUV\(_{max}\)) of affected myocardium were calculated and compared with both remote myocardium and left ventricular (LV) cavity. SSTR-PET was positive in 7/15, CMR in 10/15 patients. Of the 3 CMR+/PET- subjects, one patient with minor involvement (<25\% of wall thickness in CMR) was missed by PET. The remaining two CMR+/PET- patients displayed no adverse cardiac events during follow-up. In the 17-segment model, PET/CT yielded 27 and CMR 29 positive segments. Overall concordance of the 2 modalities was 96.1\% (245/255 segments analyzed). SUV\(_{mean}\) and SUV\(_{max}\) in inflamed areas were 2.0±1.2 and 2.6±1.2, respectively. The lesion-to-remote myocardium and lesion-to-LV cavity ratios were 1.8±0.2 and 1.9±0.2 for SUV\(_{mean}\) and 2.0±0.3 and 1.7±0.3 for SUV\(_{max}\), respectively. Detection of cardiac sarcoidosis by SSTR-PET/CT is feasible. Our data warrant further analysis in larger prospective series.}, language = {en} } @article{ReiterRitterNordbecketal.2012, author = {Reiter, Theresa and Ritter, Oliver and Nordbeck, Peter and Beer, Meinrad and Bauer, Wolfgang Rudolf}, title = {MRI-guided ablation of wide complex tachycardia in a univentricular heart}, series = {World Journal of Cardiology}, volume = {4}, journal = {World Journal of Cardiology}, number = {8}, doi = {10.4330/wjc.v4.i8.260}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123165}, pages = {260-263}, year = {2012}, abstract = {Magnetic resonance imaging can be used for preprocedural assessment of complex anatomy for radiofrequency (RF) ablations, e.g., in a univentricular heart. This case report features the treatment of a young patient with a functionally univentricular heart who suffered from persistent sudden onset tachycardia with wide complexes that required RF ablation as treatment.}, language = {en} } @article{PickhardSieglBaumannetal.2014, author = {Pickhard, Anja and Siegl, Michael and Baumann, Alexander and Huhn, Maximilian and Wirth, Markus and Reiter, Rudolf and Rudelius, Martina and Piontek, Guido and Brockhoff, Gero}, title = {The response of head and neck squamous cell carcinoma to cetuximab treatment depends on Aurora kinase A polymorphism}, series = {Oncotarget}, volume = {5}, journal = {Oncotarget}, number = {14}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120757}, pages = {5428-38}, year = {2014}, abstract = {Objectives: The aim of this study was to evaluate the efficiency of cetuximab-based anti-EGFR treatment and Aurora kinase A / B knockdown as a function of Aurora kinase polymorphism in HNSCC cell lines. Materials and methods: First, protein expression of Aurora kinase A / B and EGFR and Aurora kinase A polymorphism were studied in tumour samples. The survival and proliferation of Aurora kinase A homo- (Cal27) and heterozygous (HN) HNSCC cell lines was evaluated using a colony formation assay and a flow cytometric assay. Also, aneuploidy was determined. EGFR signalling pathway were visualised by western blotting. Results: Immunohistochemistry revealed the overexpression of Aurora kinase A / B in HNSCC. The knockdown of each kinase caused a significant decrease in clonogenic survival, independent of Aurora kinase A polymorphism. In contrast, cetuximab treatment impaired clonogenic survival only in the Aurora kinase A-homozygous cell line (Cal27). Conclusion: This study provides in vitro evidence for the predictive value of Aurora kinase A polymorphism in the efficiency of cetuximab treatment. Resistance to cetuximab treatment can be overcome by simultaneous Aurora kinase A/B knockdown.}, language = {en} } @article{SchieflerPiontekDoescheretal.2014, author = {Schiefler, Carlotta and Piontek, Guido and Doescher, Johannes and Schuettler, Dominik and Mißlbeck, Martin and Rudelius, Martina and Haug, Anna and Reiter, Rudolf and Brockhoff, Gero and Pickhard, Anja}, title = {Inhibition of SphK1 reduces radiation-induced migration and enhances sensitivity to cetuximab treatment by affecting the EGFR/SphK1 crosstalk}, series = {Oncotarget}, volume = {5}, journal = {Oncotarget}, number = {20}, issn = {1949-2553}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120929}, pages = {9877-9888}, year = {2014}, abstract = {SphK1 is known to play a role in tumor progression, resistance to radiochemotherapy, and migration patterns. As the overall survival rates of squamous cell carcinoma of the head and neck (HNSCC) remain poor due to limitations in surgery and irradiation and chemotherapy resistance, SphK1 is an important enzyme to investigate. The purpose of this study was to elucidate the impact of SphK1 on irradiation efficacy of HNSCC in-vitro with emphasis on EGFR signaling. By immunhistochemical staining we found a positive correlation between EGFR and SphK1 expression in patient specimens. In colony formation assays irradiation sensitive cell lines showed a poor response to cetuximab, an EGFR inhibitor, and SKI-II, a SphK1 inhibitor, and vice versa. In irradiation sensitive cells an enhanced reduction of cell migration and survival was found upon simultaneous targeting of EGFR and SphK1. In the present study, we elucidated a linkage between the two signaling pathways with regard to the efficacy of cetuximab treatment and the impact on the migration behavior of tumor cells. We investigated the biological impact of inhibiting these pathways and examined the biochemical implications after different treatments. An understanding of the processes involved could help to improve the treatment of patients with HNSCC.}, language = {en} } @article{KampfBauerReiter2018, author = {Kampf, Thomas and Bauer, Wolfgang Rudolf and Reiter, Theresa}, title = {Improved post-processing strategy for MOLLI based tissue characterization allows application in patients with dyspnoe and impaired left ventricular function}, series = {Zeitschrift f{\"u}r Medizinische Physik}, volume = {28}, journal = {Zeitschrift f{\"u}r Medizinische Physik}, doi = {10.1016/j.zemedi.2017.07.003}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325481}, pages = {25-35}, year = {2018}, abstract = {Contrast and non-contrast MRI based characterization of myocardium by T1-mapping will be of paramount importance to obtain biomarkers, e.g. fibrosis, which determines the risk of heart failure patients. T1-mapping by the standard post-processing of the modified look-locker inversion recovery (MOLLI) lacks of accuracy when trying to reduce its duration, which on the other hand, is highly desirable in patients with heart failure. The recently suggested inversion group fitting (IGF) technique, which considers more parameters for fitting, has a superior accuracy for long T1 times despite a shorter duration. However, for short T1 values, the standard method has a superior precision. A conditional fitting routine is proposed which ideally takes advantage of both algorithms. Materials and methods All measurements were performed on a 1.5 T clinical scanner (ACHIEVA, Philips Healthcare, The Netherlands) using a MOLLI 5(n)3(n)3 prototype with n(heart beats) being a variable waiting time between inversion experiments. Phantom experiments covered a broad range of T1 times, waiting times and heart rates. A saturation recovery experiment served as a gold standard for T1 measurement. All data were analyzed with the standard MOLLI, the IGF fit and the conditional fitting routine and the obtained T1 values were compared with the gold standard. In vivo measurements were performed in a healthy volunteer and a total of 34 patients with normal findings, dilative cardiomyopathy and amyloidosis. Results Theoretical analysis and phantom experiments provided a threshold value for an apparent IGF determining processing with IGF post processing for values above, or switching to the standard technique for values below. This was validated in phantoms and patients measurements. A reduction of the waiting time to 1 instead of 3 heart beats between the inversion experiments showed reliable results. The acquisition time was reduced from 17 to 13 heart beats. The in vivo measurements showed ECV values between 25\% (18-33\%; SD 0.03) in the healthy, 30\% (22-40\%; SD 0.04) in patients with DCM and 45\% (30-60\%; SD 0.9) in patients with amyloidosis. Conclusion The adopted post-processing algorithm determines long T1 values with high accuracy and short T1 values while maintaining a high precision. Based on reduction of waiting time, and independence of heart rate, it shortens breath hold duration and allows fast T1-mapping, which is frequently a prerequisite in patients with cardiac diseases.}, language = {en} } @article{KampfReiterBauer2018, author = {Kampf, Thomas and Reiter, Theresa and Bauer, Wolfgang Rudolf}, title = {An analytical model which determines the apparent T1 for Modified Look-Locker Inversion Recovery - Analysis of the longitudinal relaxation under the influence of discontinuous balanced (classical MOLLI) and spoiled gradient echo readouts}, series = {Zeitschrift f{\"u}r Medizinische Physik}, volume = {28}, journal = {Zeitschrift f{\"u}r Medizinische Physik}, doi = {10.1016/j.zemedi.2017.07.004}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325498}, pages = {150-157}, year = {2018}, abstract = {Quantitative nuclear magnetic resonance imaging (MRI) shifts more and more into the focus of clinical research. Especially determination of relaxation times without/and with contrast agents becomes the foundation of tissue characterization, e.g. in cardiac MRI for myocardial fibrosis. Techniques which assess longitudinal relaxation times rely on repetitive application of readout modules, which are interrupted by free relaxation periods, e.g. the Modified Look-Locker Inversion Recovery = MOLLI sequence. These discontinuous sequences reveal an apparent relaxation time, and, by techniques extrapolated from continuous readout sequences, a putative real T1 is determined. What is missing is a rigorous analysis of the dependence of the apparent relaxation time on its real partner, readout sequence parameters and biological parameters as heart rate. This is provided in this paper for the discontinuous balanced steady state free precession (bSSFP) and spoiled gradient echo readouts. It turns out that the apparent longitudinal relaxation rate is the time average of the relaxation rates during the readout module, and free relaxation period. Knowing the heart rate our results vice versa allow to determine the real T1 from its measured apparent partner.}, language = {en} }