@article{WeichWernerBucketal.2021,
  author    = {Weich, Alexander and Werner, Rudolf A. and Buck, Andreas K. and Hartrampf, Philipp E. and Serfling, Sebastian E. and Scheurlen, Michael and Wester, Hans-J{\"u}rgen and Meining, Alexander and Kircher, Stefan and Higuchi, Takahiro and Pomper, Martin G. and Rowe, Steven P. and Lapa, Constantin and Kircher, Malte},
  title     = {CXCR4-Directed PET/CT in Patients with Newly Diagnosed Neuroendocrine Carcinomas},
  series = {Diagnostics},
  volume    = {11},
  journal   = {Diagnostics},
  number    = {4},
  issn      = {2075-4418},
  doi       = {10.3390/diagnostics11040605},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234231},
  year      = {2021},
  abstract  = {We aimed to elucidate the diagnostic potential of the C-X-C motif chemokine receptor 4 (CXCR4)-directed positron emission tomography (PET) tracer \(^{68}\)Ga-Pentixafor in patients with poorly differentiated neuroendocrine carcinomas (NEC), relative to the established reference standard \(^{18}\)F-FDG PET/computed tomography (CT). In our database, we retrospectively identified 11 treatment-na{\"i}ve patients with histologically proven NEC, who underwent \(^{18}\)F-FDG and CXCR4-directed PET/CT for staging and therapy planning. The images were analyzed on a per-patient and per-lesion basis and compared to immunohistochemical staining (IHC) of CXCR4 from PET-guided biopsies. \(^{68}\)Ga-Pentixafor visualized tumor lesions in 10/11 subjects, while \(^{18}\)F-FDG revealed sites of disease in all 11 patients. Although weak to moderate CXCR4 expression could be corroborated by IHC in 10/11 cases, \(^{18}\)F-FDG PET/CT detected significantly more tumor lesions (102 vs. 42; total lesions, n = 107; p < 0.001). Semi-quantitative analysis revealed markedly higher 18F-FDG uptake as compared to \(^{68}\)Ga-Pentixafor (maximum and mean standardized uptake values (SUV) and tumor-to-background ratios (TBR) of cancerous lesions, SUVmax: 12.8 ± 9.8 vs. 5.2 ± 3.7; SUVmean: 7.4 ± 5.4 vs. 3.1 ± 3.2, p < 0.001; and, TBR 7.2 ± 7.9 vs. 3.4 ± 3.0, p < 0.001). Non-invasive imaging of CXCR4 expression in NEC is inferior to the reference standard \(^{18}\)F-FDG PET/CT.},
  language  = {en}
}
@article{WernerKircherHiguchietal.2019,
  author    = {Werner, Rudolf A. and Kircher, Stefan and Higuchi, Takahiro and Kircher, Malte and Schirbel, Andreas and Wester, Hans-J{\"u}rgen and Buck, Andreas K. and Pomper, Martin G. and Rowe, Steven P. and Lapa, Constantin},
  title     = {CXCR4-directed imaging in solid tumors},
  series = {Frontiers in Oncology},
  volume    = {9},
  journal   = {Frontiers in Oncology},
  number    = {770},
  issn      = {2234-943X},
  doi       = {10.3389/fonc.2019.00770},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-195678},
  year      = {2019},
  abstract  = {Despite histological evidence in various solid tumor entities, available experience with CXCR4-directed diagnostics and endoradiotherapy mainly focuses on hematologic diseases. With the goal of expanding the application of CXCR4 theranostics to solid tumors, we aimed to elucidate the feasibility of CXCR4-targeted imaging in a variety of such neoplasms. Methods: Nineteen patients with newly diagnosed, treatment-na{\"i}ve solid tumors including pancreatic adenocarcinoma or neuroendocrine tumor, cholangiocarcinoma, hepatocellular carcinoma, renal cell carcinoma, ovarian cancer, and prostate cancer underwent [\(^{68}\)Ga]Pentixafor PET/CT. CXCR4-mediated uptake was assessed both visually and semi-quantitatively by evaluation of maximum standardized uptake values (SUV\(_{max}\)) of both primary tumors and metastases. With physiologic liver uptake as reference, tumor-to-background ratios (TBR) were calculated. [\(^{68}\)Ga]Pentixafor findings were further compared to immunohistochemistry and [\(^{18}\)F]FDG PET/CT. Results: On [\(^{68}\)Ga]Pentixafor PET/CT, 10/19 (52.6\%) primary tumors were visually detectable with a median SUVmax of 5.4 (range, 1.7-16.0) and a median TBR of 2.6 (range, 0.8-7.4), respectively. The highest level of radiotracer uptake was identified in a patient with cholangiocarcinoma (SUVmax, 16.0; TBR, 7.4). The relatively low uptake on [\(^{68}\)Ga]Pentixafor was also noted in metastases, exhibiting a median SUVmax of 4.5 (range, 2.3-8.8; TBR, 1.7; range, 1.0-4.1). A good correlation between uptake on [\(^{68}\)Ga]Pentixafor and histological derived CXCR4 expression was noted (R = 0.62, P < 0.05). In the 3 patients in whom [\(^{18}\)F]FDG PET/CT was available, [\(^{68}\)Ga]Pentixafor exhibited lower uptake in all lesions. Conclusions: In this cohort of newly diagnosed, treatment-na{\"i}ve patients with solid malignancies, CXCR4 expression as detected by [\(^{68}\)Ga]Pentixafor-PET/CT and immunohistochemistry was rather moderate. Thus, CXCR4-directed imaging may not play a major role in the management of solid tumors in the majority of patients.},
  language  = {en}
}
@article{GrimmLazariotouKircheretal.2010,
  author    = {Grimm, Martin and Lazariotou, Maria and Kircher, Stefan and Stuermer, Luisa and Reiber, Christoph and Hoefelmayr, Andreas and Gattenloehner, Stefan and Otto, Christoph and Germer, Christoph T. and von Rahden, Burkhard H. A.},
  title     = {MMP-1 is a (pre-)invasive factor in Barrett-associated esophageal adenocarcinomas and is associated with positive lymph node status},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68293},
  year      = {2010},
  abstract  = {Background: Esophageal adenocarcinomas (EACs) arise due to gastroesophageal reflux, with Barrett's esophagus (BE) regarded as precancerous lesion. Matrix metalloproteinases (MMPs) might play a role during the multistep carcinogenetic process. Methods: Expression of MMP-1 and -13 was analyzed in esophageal cancer (n = 41 EAC with BE, n = 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC), furthermore in BE without intraepithelial neoplasia (IN) (n = 18), and the cell line OE-33. MMP-1 was co-labelled with Ki-67 (proliferation), Cdx-2 (marker for intestinal metaplasia, BE) and analyzed on mRNA level. MMP-1 staining results were correlated with clinicopatholocical parameters. Results: On protein level, MMP-1 expression was found in 39 of 41 (95\%) EAC with BE, in 19 of 19 (100\%) EAC without BE, in 6 of 10 (60\%) ESCC, and in 10 of 18 (56\%) BE without IN. No expression of MMP-13 was found in these specimens. Quantification showed 48\% MMP-1 positive cells in EAC with BE, compared to 35\% in adjacent BE (p < 0.05), 44\% in EAC without BE, 32\% in ESCC, and 4\% in BE without IN. Immunofluorescence double staining experiments revealed increased MMP-1 expressing in proliferating cells (MMP-1+/Ki-67+) (r = 0.943 for BE and r = 0.811 for EAC). On mRNA-level, expression of MMP-1 was significantly higher in EAC compared to BE (p = 0.01) and confirmed immunohistochemical staining results. High MMP-1 levels were associated with lymph node metastases but not with poorer survival (p = 0.307). Conclusions: Our findings suggest that MMP-1 plays a role as preinvasive factor in BE-associated EAC. Expression of MMP-1 in proliferating BE and EAC cells suggest malignant proliferation following the clonal expansion model.},
  subject      = {Medizin},
  language  = {en}
}
@article{LenschowFussKircheretal.2021,
  author    = {Lenschow, Christina and Fuss, Carmina Teresa and Kircher, Stefan and Buck, Andreas and Kickuth, Ralph and Reibetanz, Joachim and Wiegering, Armin and Stenzinger, Albrecht and H{\"u}bschmann, Daniel and Germer, Christoph Thomas and Fassnacht, Martin and Fr{\"o}hling, Stefan and Schlegel, Nicolas and Kroiss, Matthias},
  title     = {Case Report: Abdominal Lymph Node Metastases of Parathyroid Carcinoma: Diagnostic Workup, Molecular Diagnosis, and Clinical Management},
  series = {Frontiers in Endocrinology},
  volume    = {12},
  journal   = {Frontiers in Endocrinology},
  issn      = {1664-2392},
  doi       = {10.3389/fendo.2021.643328},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233362},
  year      = {2021},
  abstract  = {Parathyroid carcinoma (PC) is an orphan malignancy accounting for only ~1\% of all cases with primary hyperparathyroidism. The localization of recurrent PC is of critical importance and can be exceedingly difficult to diagnose and sometimes futile when common sites of recurrence in the neck and chest cannot be confirmed. Here, we present the diagnostic workup, molecular analysis and multimodal therapy of a 46-year old woman with the extraordinary manifestation of abdominal lymph node metastases 12 years after primary diagnosis of PC. The patient was referred to our endocrine tumor center in 2016 with the aim to localize the tumor causative of symptomatic biochemical recurrence. In view of the extensive previous workup we decided to perform [18F]FDG-PET-CT. A pathological lymph node in the liver hilus showed slightly increased FDG-uptake and hence was suspected as site of recurrence. Selective venous sampling confirmed increased parathyroid hormone concentration in liver veins. Abdominal lymph node metastasis was resected and histopathological examination confirmed PC. Within four months, the patient experienced biochemical recurrence and based on high tumor mutational burden detected in the surgical specimen by whole exome sequencing the patient received immunotherapy with pembrolizumab that led to a biochemical response. Subsequent to disease progression repeated abdominal lymph node resection was performed in 10/2018, 01/2019 and in 01/2020. Up to now (12/2020) the patient is biochemically free of disease. In conclusion, a multimodal diagnostic approach and therapy in an interdisciplinary setting is needed for patients with rare endocrine tumors. Molecular analyses may inform additional treatment options including checkpoint inhibitors such as pembrolizumab.},
  language  = {en}
}
@article{HertleinSturmKircheretal.2011,
  author    = {Hertlein, Tobias and Sturm, Volker and Kircher, Stefan and Basse-L{\"u}sebrink, Thomas and Haddad, Daniel and Ohlsen, Knut and Jakob, Peter},
  title     = {Visualization of Abscess Formation in a Murine Thigh Infection Model of \(Staphylococcus\) \(aureus\) by (19)F-Magnetic Resonance Imaging (MRI)},
  series = {PLoS ONE},
  volume    = {6},
  journal   = {PLoS ONE},
  number    = {3},
  doi       = {10.1371/journal.pone.0018246},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142846},
  pages     = {e18246},
  year      = {2011},
  abstract  = {Background: During the last years, (19)F-MRI and perfluorocarbon nanoemulsion (PFC) emerged as a powerful contrast agent methodology to track cells and to visualize inflammation. We applied this new modality to visualize deep tissue abscesses during acute and chronic phase of inflammation caused by Staphylococcus aureus infection. Methodology and Principal Findings: In this study, a murine thigh infection model was used to induce abscess formation and PFC or CLIO (cross linked ironoxides) was administered during acute or chronic phase of inflammation. 24 h after inoculation, the contrast agent accumulation was imaged at the site of infection by MRI. Measurements revealed a strong accumulation of PFC at the abscess rim at acute and chronic phase of infection. The pattern was similar to CLIO accumulation at chronic phase and formed a hollow sphere around the edema area. Histology revealed strong influx of neutrophils at the site of infection and to a smaller extend macrophages during acute phase and strong influx of macrophages at chronic phase of inflammation. Conclusion and Significance: We introduce (19)F-MRI in combination with PFC nanoemulsions as a new platform to visualize abscess formation in a murine thigh infection model of S. aureus. The possibility to track immune cells in vivo by this modality offers new opportunities to investigate host immune response, the efficacy of antibacterial therapies and the influence of virulence factors for pathogenesis.},
  language  = {en}
}
@article{LapaKircherSchirbeletal.2017,
  author    = {Lapa, Constantin and Kircher, Stefan and Schirbel, Andreas and Rosenwald, Andreas and Kropf, Saskia and Pelzer, Theo and Walles, Thorsten and Buck, Andreas K. and Weber, Wolfgang A. and Wester, Hans-Juergen and Herrmann, Ken and L{\"u}ckerath, Katharina},
  title     = {Targeting CXCR4 with [\(^{68}\)Ga]Pentixafor: a suitable theranostic approach in pleural mesothelioma?},
  series = {Oncotarget},
  volume    = {8},
  journal   = {Oncotarget},
  number    = {57},
  doi       = {10.18632/oncotarget.18235},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169989},
  pages     = {96732-96737},
  year      = {2017},
  abstract  = {C-X-C motif chemokine receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer. This study investigated the feasibility of CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using [\(^{68}\)Ga]Pentixafor in malignant pleural mesothelioma. Six patients with pleural mesothelioma underwent [\(^{68}\)Ga]Pentixafor-PET/CT. 2′-[\(^{18}\)F]fluoro-2′-deoxy-D-glucose ([\(^{18}\)F]FDG)-PET/CT (4/6 patients) and immunohistochemistry obtained from biopsy or surgery (all) served as standards of reference. Additionally, 9 surgical mesothelioma samples were available for histological work-up. Whereas [\(^{18}\)F]FDG-PET depicted active lesions in all patients, [\(^{68}\)Ga]Pentixafor-PET/CT recorded physiologic tracer distribution and none of the 6 patients presented [\(^{68}\)Ga]Pentixafor-positive lesions. This finding paralleled results of immunohistochemistry which also could not identify relevant CXCR4 surface expression in the samples analyzed. In contrast to past reports, our data suggest widely absence of CXCR4 expression in pleural mesothelioma. Hence, robust cell surface expression should be confirmed prior to targeting this chemokine receptor for diagnosis and/or therapy.},
  language  = {en}
}
@article{vonRahdenKircherLazariotouetal.2011,
  author    = {von Rahden, Burkhard H. A. and Kircher, Stefan and Lazariotou, Maria and Reiber, Christoph and Stuermer, Luisa and Otto, Christoph and Germer, Christoph T. and Grimm, Martin},
  title     = {LgR5 expression and cancer stem cell hypothesis: clue to define the true origin of esophageal adenocarcinomas with and without Barrett's Esophagus?},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68810},
  year      = {2011},
  abstract  = {Background: Investigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barrett's Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis. Materials and methods: Expression of a putative intestinal stem cell marker LgR5 was analyzed in esophageal cancer specimen (n = 70: 41 EAC with BE, 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC) and in the adenocarcinoma cell line OE-33. Ki-67 and Cdx-2 were co-labelled with LgR5 in double staining experiments. Immunhistochemical expression results were confirmed by RT-PCR and correlated with tumor stage and five-year survival rates. Results: LgR5was found expressed in 35 of 41 (85\%) EAC with BE and in 16 of 19 (81\%) EAC without BE. By contrast, LgR5 was not found to be expressed in ESCC. Quantification of immunolabeling showed 15\% LgR5+ cells in EAC with BE, 32\% LgR5+ cells in adjacent BE and 13\% in EAC without BE. Immunofluorescence double staining experiments with LgR5 and Ki-67 revealed a subpopulation (~5\%) of proliferating LgR+/Ki-67+ cells. On mRNAlevel, expression of LgR5 was higher in BE in comparison to EAC (p = 0.0159). High levels of LgR5 expression in BE associated EAC were associated with poorer survival in univariate analysis. Conclusion: The stem cell marker LgR5 is expressed in EAC, irrespective of association with BE, and appears to have negative impact on survival. The subset of proliferating LgR5+ cells (<5\%) might resemble rapidly cycling CSCs, which needs to be substantiated in further investigations.},
  subject      = {Medizin},
  language  = {en}
}
@article{JakobHertleinSturmetal.2011,
  author    = {Jakob, Peter and Hertlein, Tobias and Sturm, Volker and Kircher, Stefan and Basse-L{\"u}sebrink, Thomas and Haddad, Daniel and Ohlsen, Knut},
  title     = {Visualization of Abscess Formation in a Murine Thigh Infection Model of Staphylococcus aureus by 19F-Magnetic Resonance Imaging (MRI)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74994},
  year      = {2011},
  abstract  = {Background: During the last years, 19F-MRI and perfluorocarbon nanoemulsion (PFC) emerged as a powerful contrast agent based MRI methodology to track cells and to visualize inflammation. We applied this new modality to visualize deep tissue abscesses during acute and chronic phase of inflammation caused by Staphylococcus aureus infection. Methodology and Principal Findings: In this study, a murine thigh infection model was used to induce abscess formation and PFC or CLIO (cross linked ironoxides) was administered during acute or chronic phase of inflammation. 24 h after inoculation, the contrast agent accumulation was imaged at the site of infection by MRI. Measurements revealed a strong accumulation of PFC at the abscess rim at acute and chronic phase of infection. The pattern was similar to CLIO accumulation at chronic phase and formed a hollow sphere around the edema area. Histology revealed strong influx of neutrophils at the site of infection and to a smaller extend macrophages during acute phase and strong influx of macrophages at chronic phase of inflammation. Conclusion and Significance: We introduce 19F-MRI in combination with PFC nanoemulsions as a new platform to visualize abscess formation in a murine thigh infection model of S. aureus. The possibility to track immune cells in vivo by this modality offers new opportunities to investigate host immune response, the efficacy of antibacterial therapies and the influence of virulence factors for pathogenesis.},
  subject      = {Staphylococcus aureus},
  language  = {en}
}
@article{vonRahdenKircherLazariotouetal.2011,
  author    = {von Rahden, Burkhard H.A. and Kircher, Stefan and Lazariotou, Maria and Reiber, Christoph and Stuermer, Luisa and Otto, Christoph and Germer, Christoph T. and Grimm, Martin},
  title     = {LgR5 expression and cancer stem cell hypothesis: clue to define the true origin of esophageal adenocarcinomas with and without Barrett's Esophagus?},
  series = {Journal of Experimental \& Clinical Cancer Research},
  volume    = {30},
  journal   = {Journal of Experimental \& Clinical Cancer Research},
  number    = {23},
  doi       = {10.1186/1756-9966-30-23},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137783},
  year      = {2011},
  abstract  = {Background Investigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barrett's Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis. Materials and methods Expression of a putative intestinal stem cell marker LgR5 was analyzed in esophageal cancer specimen (n = 70: 41 EAC with BE, 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC) and in the adenocarcinoma cell line OE-33. Ki-67 and Cdx-2 were co-labelled with LgR5 in double staining experiments. Immunhistochemical expression results were confirmed by RT-PCR and correlated with tumor stage and five-year survival rates. Results LgR5was found expressed in 35 of 41 (85\%) EAC with BE and in 16 of 19 (81\%) EAC without BE. By contrast, LgR5 was not found to be expressed in ESCC. Quantification of immunolabeling showed 15\% LgR5+ cells in EAC with BE, 32\% LgR5+ cells in adjacent BE and 13\% in EAC without BE. Immunofluorescence double staining experiments with LgR5 and Ki-67 revealed a subpopulation (~5\%) of proliferating LgR+/Ki-67+ cells. On mRNA-level, expression of LgR5 was higher in BE in comparison to EAC (p = 0.0159). High levels of LgR5 expression in BE associated EAC were associated with poorer survival in univariate analysis. Conclusion The stem cell marker LgR5 is expressed in EAC, irrespective of association with BE, and appears to have negative impact on survival. The subset of proliferating LgR5+ cells (<5\%) might resemble rapidly cycling CSCs, which needs to be substantiated in further investigations.},
  language  = {en}
}
@article{BalaRonchiPichletal.2014,
  author    = {Bala, Margarita and Ronchi, Cristina L. and Pichl, Josef and Wild, Vanessa and Kircher, Stefan and Allolio, Bruno and Hahner, Stefanie},
  title     = {Suspected metastatic adrenocortical carcinoma revealing as pulmonary Kaposi sarcoma in adrenal Cushing's syndrome},
  doi       = {10.1186/1472-6823-14-63},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110553},
  year      = {2014},
  abstract  = {Background Kaposi sarcoma (KS) is a malignant disease most commonly diagnosed in the setting of a human immunodeficiency virus (HIV) infection and in patients receiving immunosuppressive treatment. Pulmonary KS has never been reported in association with endogenous Cushing's syndrome (CS). Case presentation A 60-year-old woman presented with symptoms and signs of CS. Adrenal CS was confirmed by standard biochemical evaluation. Imaging revealed a right adrenal lesion (diameter 3.5 cm) and multiple pulmonary nodules, suggesting a cortisol-secreting adrenal carcinoma with pulmonary metastases. The patient underwent right adrenalectomy with a pathohistological diagnosis of an adrenal adenoma. Subsequent thoracoscopic wedge resection of one lung lesion revealed pulmonary KS with positive immunostaining for human herpes virus 8 (HHV-8). HIV-serology was negative. Hydrocortisone replacement was initiated for secondary adrenal insufficiency after surgery. Post-operative follow up imaging showed complete remission of all KS-related pulmonary nodules solely after resolution of hypercortisolism. Conclusion KS may occur in the setting of endogenous CS and may go into remission after cure of hypercortisolism without further specific treatment.},
  language  = {en}
}