@article{WestermaierLinsenmannHomolaetal.2016, author = {Westermaier, Thomas and Linsenmann, Thomas and Homola, Gy{\"o}rgy A. and Loehr, Mario and Stetter, Christian and Willner, Nadine and Ernestus, Ralf-Ingo and Soymosi, Laszlo and Vince, Giles H.}, title = {3D rotational fluoroscopy for intraoperative clip control in patients with intracranial aneurysms - assessment of feasibility and image quality}, series = {BMC Medical Imaging}, volume = {16}, journal = {BMC Medical Imaging}, number = {30}, doi = {10.1186/s12880-016-0133-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146381}, year = {2016}, abstract = {Background Mobile 3D fluoroscopes have become increasingly available in neurosurgical operating rooms. In this series, the image quality and value of intraoperative 3D fluoroscopy with intravenous contrast agent for the evaluation of aneurysm occlusion and vessel patency after clip placement was assessed in patients who underwent surgery for intracranial aneurysms. Materials and methods Twelve patients were included in this retrospective analysis. Prior to surgery, a 360° rotational fluoroscopy scan was performed without contrast agent followed by another scan with 50 ml of intravenous iodine contrast agent. The image files of both scans were transferred to an Apple PowerMac® workstation, subtracted and reconstructed using OsiriX® free software. The procedure was repeated after clip placement. Both image sets were compared for assessment of aneurysm occlusion and vessel patency. Results Image acquisition and contrast administration caused no adverse effects. Image quality was sufficient to follow the patency of the vessels distal to the clip. Metal artifacts reduce the assessability of the immediate vicinity of the clip. Precise image subtraction and post-processing can reduce metal artifacts and make the clip-site assessable and depict larger neck-remnants. Conclusion This technique quickly supplies images at adequate quality to evaluate distal vessel patency after aneurysm clipping. Significant aneurysm remnants may be depicted as well. As it does not require visual control of all vessels that are supposed to be evaluated intraoperatively, this technique may be complementary to other intraoperative tools like indocyanine green videoangiography and micro-Doppler, especially for the assessment of larger aneurysms. At the momentary state of this technology, it cannot replace postoperative conventional angiography. However, 3D fluoroscopy and image post-processing are young technologies. Further technical developments are likely to result in improved image quality.}, language = {en} } @article{LapaLueckerathKleinleinetal.2016, author = {Lapa, Constantin and L{\"u}ckerath, Katharina and Kleinlein, Irene and Monoranu, Camelia Maria and Linsenmann, Thomas and Kessler, Almuth F. and Rudelius, Martina and Kropf, Saskia and Buck, Andreas K. and Ernestus, Ralf-Ingo and Wester, Hans-J{\"u}rgen and L{\"o}hr, Mario and Herrmann, Ken}, title = {\(^{68}\)Ga-Pentixafor-PET/CT for Imaging of Chemokine Receptor 4 Expression in Glioblastoma}, series = {Theranostics}, volume = {6}, journal = {Theranostics}, number = {3}, doi = {10.7150/thno.13986}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168174}, pages = {428-434}, year = {2016}, abstract = {Chemokine receptor-4 (CXCR4) has been reported to be overexpressed in glioblastoma (GBM) and to be associated with poor survival. This study investigated the feasibility of non-invasive CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using the radiolabelled chemokine receptor ligand \(^{68}\)Ga-Pentixafor. 15 patients with clinical suspicion on primary or recurrent glioblastoma (13 primary, 2 recurrent tumors) underwent \(^{68}\)Ga-Pentixafor-PET/CT for assessment of CXCR4 expression prior to surgery. O-(2-\(^{18}\)F-fluoroethyl)-L-tyrosine (\(^{18}\)F-FET) PET/CT images were available in 11/15 cases and were compared visually and semi-quantitatively (SUV\(_{max}\), SUV\(_{mean}\)). Tumor-to-background ratios (TBR) were calculated for both PET probes. \(^{68}\)Ga-Pentixafor-PET/CT results were also compared to histological CXCR4 expression on neuronavigated surgical samples. \(^{68}\)Ga-Pentixafor-PET/CT was visually positive in 13/15 cases with SUV\(_{mean}\) and SUV\(_{max}\) of 3.0±1.5 and 3.9±2.0 respectively. Respective values for \(^{18}\)F-FET were 4.4±2.0 (SUV\(_{mean}\)) and 5.3±2.3 (SUV\(_{max}\)). TBR for SUV\(_{mean}\) and SUV\(_{max}\) were higher for \(^{68}\)Ga-Pentixafor than for \(^{18}\)F-FET (SUV\(_{mean}\) 154.0±90.7 vs. 4.1±1.3; SUV\(_{max}\) 70.3±44.0 and 3.8±1.2, p<0.01), respectively. Histological analysis confirmed CXCR4 expression in tumor areas with high \(^{68}\)Ga-Pentixafor uptake; regions of the same tumor without apparent \(^{68}\)Ga-Pentixafor uptake showed no or low receptor expression. In this pilot study, \(^{68}\)Ga-Pentixafor retention has been observed in the vast majority of glioblastoma lesions and served as readout for non-invasive determination of CXCR4 expression. Given the paramount importance of the CXCR4/SDF-1 axis in tumor biology, \(^{68}\)Ga-Pentixafor-PET/CT might prove a useful tool for sensitive, non-invasive in-vivo quantification of CXCR4 as well as selection of patients who might benefit from CXCR4-directed therapy.}, language = {en} } @article{LinsenmannMonoranuKessleretal.2013, author = {Linsenmann, Thomas and Monoranu, Camelia M. and Kessler, Almuth F. and Ernestus, Ralf I. and Westermaier, Thomas}, title = {Bone chips, fibrin glue, and osteogeneration following lateral suboccipital craniectomy: a case report}, series = {BMC Research Notes}, journal = {BMC Research Notes}, doi = {10.1186/1756-0500-6-523}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97346}, year = {2013}, abstract = {Background Suboccipital craniectomy is a conventional approach for exploring cerebellopontine angle lesions. A variety of techniques have been successfully employed to reconstruct a craniectomy. This is the first report about the histological findings after performing a cranioplasty by using a mixture of autologous bone chips and human allogenic fibrin glue. Case presentation A 53-year-old German woman underwent left lateral suboccipital retrosigmoidal craniectomy for treatment of trigeminal neuralgia in 2008. Cranioplasty was perfomed by using a mixture of autologous bone chips and human allogenic fibrin glue. Due to recurrent neuralgia, a second left lateral suboccipital craniectomy was performed in 2012. The intraoperative findings revealed a complete ossification of the former craniotomy including widely mature trabecular bone tissue in the histological examination. Conclusion A mixture of autologous bone chips and human allogenic fibrin glue seems to provide sufficient bone-regeneration revealed by histological and neuroradiological examinations.}, language = {en} } @article{LinsenmannMonoranuAlkonyietal.2019, author = {Linsenmann, Thomas and Monoranu, Camelia M. and Alkonyi, Balint and Westermaier, Thomas and Hagemann, Carsten and Kessler, Almuth F. and Ernestus, Ralf-Ingo and L{\"o}hr, Mario}, title = {Cerebellar liponeurocytoma - molecular signature of a rare entity and the importance of an accurate diagnosis}, series = {Interdisciplinary Neurosurgery}, volume = {16}, journal = {Interdisciplinary Neurosurgery}, doi = {10.1016/j.inat.2018.10.017}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177652}, pages = {7-11}, year = {2019}, abstract = {Background: Cerebellar liponeurocytoma is an extremely rare tumour entity of the central nervous system. It is histologically characterised by prominent neuronal/neurocytic differentiation with focal lipidisation and corresponding histologically to WHO grade II. It typically develops in adults, and usually shows a low proliferative potential. Recurrences have been reported in almost 50\% of cases, and in some cases the recurrent tumour may display increased mitotic activity and proliferation index, vascular proliferations and necrosis. Thus pathological diagnosis of liponeurocytoma is challenging. This case presentation highlights the main clinical, radiographic and pathological features of a cerebellar liponeurocytoma. Case presentation: A 59-year-old, right-handed woman presented at our department with a short history of persistent headache, vertigo and gait disturbances. Examination at presentation revealed that the patient was awake, alert and fully oriented. The cranial nerve status was normal. Uncertainties were noted in the bilateral finger-to-nose testing with bradydiadochokinesis on both sides. Strength was full and no pronator drift was observed. Sensation was intact. No signs of pyramidal tract dysfunction were detected. Her gait appeared insecure. The patient underwent surgical resection. Afterward no further disturbances could be detected. Conclusions: To date >40 cases of liponeurocytoma have been reported, including cases with supratentorial location. A review of the 5 published cases of recurrent cerebellar. Liponeurocytoma revealed that the median interval between the first and second relapse was rather short, indicating uncertain malignant potential. The most recent WHO classification of brain tumours (2016) classifies the cerebellar liponeurocytoma as a separate entity and assigns the tumour to WHO grade II. Medulloblastoma is the most important differential diagnosis commonly seen in children and young adults. In contrast, cerebellar liponeurocytoma is typically diagnosed in adults. The importance of accurate diagnosis should not be underestimated especially in the view of possible further therapeutic interventions and for the determination of the patient's prognosis.}, language = {en} } @article{HagemannNeuhausDahlmannetal.2019, author = {Hagemann, Carsten and Neuhaus, Nikolas and Dahlmann, Mathias and Kessler, Almuth F. and Kobelt, Dennis and Herrmann, Pia and Eyrich, Matthias and Freitag, Benjamin and Linsenmann, Thomas and Monoranu, Camelia M. and Ernestus, Ralf-Ingo and L{\"o}hr, Mario and Stein, Ulrike}, title = {Circulating MACC1 transcripts in glioblastoma patients predict prognosis and treatment response}, series = {Cancers}, volume = {11}, journal = {Cancers}, number = {6}, issn = {2072-6694}, doi = {10.3390/cancers11060825}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197327}, year = {2019}, abstract = {Glioblastoma multiforme is the most aggressive primary brain tumor of adults, but lacksreliable and liquid biomarkers. We evaluated circulating plasma transcripts of metastasis-associatedin colon cancer-1 (MACC1), a prognostic biomarker for solid cancer entities, for prediction of clinicaloutcome and therapy response in glioblastomas. MACC1 transcripts were significantly higher inpatients compared to controls. Low MACC1 levels clustered together with other prognosticallyfavorable markers. It was associated with patients' prognosis in conjunction with the isocitratedehydrogenase (IDH) mutation status: IDH1 R132H mutation and low MACC1 was most favorable(median overall survival (OS) not yet reached), IDH1 wildtype and high MACC1 was worst (medianOS 8.1 months), while IDH1 wildtype and low MACC1 was intermediate (median OS 9.1 months).No patients displayed IDH1 R132H mutation and high MACC1. Patients with low MACC1 levelsreceiving standard therapy survived longer (median OS 22.6 months) than patients with high MACC1levels (median OS 8.1 months). Patients not receiving the standard regimen showed the worstprognosis, independent of MACC1 levels (low: 6.8 months, high: 4.4 months). Addition of circulatingMACC1 transcript levels to the existing prognostic workup may improve the accuracy of outcomeprediction and help define more precise risk categories of glioblastoma patients.}, language = {en} } @article{LinsenmannCattaneoMaerzetal.2021, author = {Linsenmann, Thomas and Cattaneo, Andrea and M{\"a}rz, Alexander and Weiland, Judith and Stetter, Christian and Nickl, Robert and Westermaier, Thomas}, title = {Combined frameless stereotactical biopsy and intraoperative cerebral angiography by 3D-rotational fluoroscopy with intravenous contrast administration: a feasibility study}, series = {BMC Medical Imaging}, volume = {21}, journal = {BMC Medical Imaging}, doi = {10.1186/s12880-021-00622-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270370}, year = {2021}, abstract = {Background Mobile 3-dimensional fluoroscopes are an integral part of modern neurosurgical operating theatres and can also be used in combination with free available image post processing to depict cerebral vessels. In preparation of stereotactic surgery, preoperative Computed Tomography (CT) may be required for image fusion. Contrast CT may be of further advantage for image fusion as it regards the vessel anatomy in trajectory planning. Time-consuming in-hospital transports are necessary for this purpose. Mobile 3D-fluoroscopes may be used to generate a CT equal preoperative data set without an in-hospital transport. This study was performed to determine the feasibility and image quality of intraoperative 3-dimensional fluoroscopy with intravenous contrast administration in combination with stereotactical procedures. Methods 6 patients were included in this feasibility study. After fixation in a radiolucent Mayfield clamp a rotational fluoroscopy scan was performed with 50 mL iodine contrast agent. The image data sets were merged with the existing MRI images at a planning station and visually evaluated by two observer. The operation times were compared between the frame-based and frameless systems ("skin-to-skin" and "OR entry to exit"). Results The procedure proves to be safe. The entire procedure from fluoroscope positioning to the transfer to the planning station took 5-6 min with an image acquisition time of 24 s. In 5 of 6 cases, the fused imaging was able to reproduce the vascular anatomy accurately and in good quality. Both time end-points were significantly shorter compared to frame-based interventions. Conclusion The images could easily be transferred to the planning and navigation system and were successfully merged with the MRI data set. The procedure can be completely integrated into the surgical workflow. Preoperative CT imaging or transport under anaesthesia may even be replaced by this technique in the future. Furthermore, hemorrhages can be successfully visualized intraoperatively and might prevent time delays in emergencies.}, language = {en} } @phdthesis{Linsenmann2010, author = {Linsenmann, Thomas}, title = {Das neonatale Kraniopharyngeom - Ein kasuistischer Beitrag und Literatur{\"u}bersicht}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49757}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2010}, abstract = {Das Kraniopharyngeom ist eine dysontogenetische Mittellinienfehlbildung mit raumforderndem Charakter. Die {\"A}tiopathogenese ist noch ungekl{\"a}rt. Bildgebende Verfahren (Sonographie, MRT) erm{\"o}glichen bereits pr{\"a}natal eine Diagnostik. Das neonatale Kraniopharyngeom ist sehr selten. Bisher finden sich in der Literatur nur wenige Fallberichte von denen operative Verl{\"a}ufe sowie klinische Langzeitverl{\"a}ufe bekannt sind. Es bleibt eine Kontroverse hinsichtlich Radikalit{\"a}t und Zeitpunkt der Operation, nicht aber dahingehend, dass die operationsmikroskopische Versorgung die Therapie der Wahl des neonatalen Kraniopharyngeoms darstellt. Die N{\"a}he zur hypophys{\"a}ren-hypothalamischen Achse bedingt eine hohe Komorbidit{\"a}t der Kinder pr{\"a}- und postoperativ.}, subject = {Neurochirurgie}, language = {de} } @article{FeldheimKesslerSchmittetal.2018, author = {Feldheim, Jonas and Kessler, Almuth F and Schmitt, Dominik and Wilczek, Lara and Linsenmann, Thomas and Dahlmann, Mathias and Monoranu, Camelia M and Ernestus, Ralf-Ingo and Hagemann, Carsten and L{\"o}hr, Mario}, title = {Expression of activating transcription factor 5 (ATF5) is increased in astrocytomas of different WHO grades and correlates with survival of glioblastoma patients}, series = {OncoTargets and Therapy}, volume = {11}, journal = {OncoTargets and Therapy}, doi = {10.2147/OTT.S176549}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177541}, pages = {8673-8684}, year = {2018}, abstract = {Background: ATF5 suppresses differentiation of neuroprogenitor cells and is overexpressed in glioblastoma (GBM). A reduction of its expression leads to apoptotic GBM cell death. Data on ATF5 expression in astrocytoma WHO grade II (low-grade astrocytoma [LGA]) are scarce and lacking on recurrent GBM. Patients and methods: ATF5 mRNA was extracted from frozen samples of patients' GBM (n=79), LGA (n=40), and normal brain (NB, n=10), quantified by duplex qPCR and correlated with retrospectively collected clinical data. ATF5 protein expression was evaluated by measuring staining intensity on immunohistochemistry. Results: ATF5 mRNA was overexpressed in LGA (sevenfold, P<0.001) and GBM (tenfold, P<0.001) compared to NB, which was confirmed on protein level. Although ATF5 mRNA expression in GBM showed a considerable fluctuation range, groups of varying biological behavior, that is, local/multifocal growth or primary tumor/relapse and the tumor localization at diagnosis, were not significantly different. ATF5 mRNA correlated with the patients' age (r=0.339, P=0.028) and inversely with Ki67-staining (r=-0.421, P=0.007). GBM patients were allocated to a low and a high ATF5 expression group by the median ATF5 overexpression compared to NB. Kaplan-Meier analysis and Cox regression indicated that ATF5 mRNA expression significantly correlated with short-term survival (t<12 months, median survival 18 vs 13 months, P=0.022, HR 2.827) and progression-free survival (PFS) (12 vs 6 months, P=0.024). This advantage vanished after 24 months (P=0.084). Conclusion: ATF5 mRNA expression could be identified as an additional, though not independent factor correlating with overall survival and PFS. Since its inhibition might lead to the selective death of glioma cells, it might serve as a potential ubiquitous therapeutic target in astrocytic tumors.}, language = {en} } @article{HagemannKesslerWiesneretal.2014, author = {Hagemann, Carsten and Kessler, Almuth Friederike and Wiesner, Miriam and Denner, Joachim and K{\"a}mmerer, Ulrike and Vince, Giles Hamilton and Linsenmann, Thomas and L{\"o}hr, Mario and Ernestus, Ralf-Ingo}, title = {Expression-analysis of the human endogenous retrovirus HERV-K in human astrocytic tumors}, doi = {10.1186/1756-0500-7-159}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110211}, year = {2014}, abstract = {Background The human endogenous retrovirus K (HERV-K) has been acquired by the genome of human ancestors million years ago. It is the most complete of the HERVs with transcriptionally active gag, pol and env genes. Splice variants of env, which are rec, 1.5 kb transcript and Np9 have been suggested to be tumorigenic. Transcripts of HERV-K have been detected in a multitude of human cancers. However, no such reports are available concerning glioblastomas (GBM), the most common malignant brain tumor in adults. Patients have a limited prognosis of 14.6 months in median, despite standard treatment. Therefore, we elucidated whether HERV-K transcripts could be detected in these tumors and serve as new molecular target for treatment. Findings We analyzed human GBM cell lines, tissue samples from patients and primary cell cultures of different passages for HERV-K full length mRNA and env, rec and 1.5 kb transcripts. While the GBM cell lines U138, U251, U343 and GaMG displayed weak and U87 strong expression of the full length HERV-K, the splice products could not be detected, despite a weak expression of env mRNA in U87 cells. Very few tissue samples from patients showed weak expression of env mRNA, but none of the rec or 1.5 kb transcripts. Primary cells expressed the 1.5 kb transcript weakly in early passages, but lost HERV-K expression with extended culture time. Conclusions These data suggest that HERV-K splice products do not play a role in human malignant gliomas and therefore, are not suitable as targets for new therapy regimen.}, language = {en} } @article{WestermaierKoehlerLinsenmannetal.2015, author = {Westermaier, Thomas and Koehler, Stefan and Linsenmann, Thomas and Kinderlen, Michael and Pakos, Paul and Ernestus, Ralf-Ingo}, title = {Intraoperative Myelography in Cervical Multilevel Stenosis Using 3D Rotational Fluoroscopy: Assessment of Feasibility and Image Quality}, series = {Radiology Research and Practice}, volume = {2015}, journal = {Radiology Research and Practice}, doi = {10.1155/2015/498936}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125779}, pages = {498936}, year = {2015}, abstract = {Background. Intraoperative myelography has been reported for decompression control in multilevel lumbar disease. Cervical myelography is technically more challenging. Modern 3D fluoroscopy may provide a new opportunity supplying multiplanar images. This study was performed to determine the feasibility and image quality of intraoperative cervical myelography using a 3D fluoroscope. Methods. The series included 9 patients with multilevel cervical stenosis. After decompression, 10 mL of water-soluble contrast agent was administered via a lumbar drainage and the operating table was tilted. Thereafter, a 3D fluoroscopy scan (O-Arm) was performed and visually evaluated. Findings. The quality of multiplanar images was sufficient to supply information about the presence of residual stenosis. After instrumentation, metal artifacts lowered image quality. In 3 cases, decompression was continued because myelography depicted residual stenosis. In one case, anterior corpectomy was not completed because myelography showed sufficient decompression after 2-level discectomy. Interpretation. Intraoperative myelography using 3D rotational fluoroscopy is useful for the control of surgical decompression in multilevel spinal stenosis providing images comparable to postmyelographic CT. The long duration of contrast delivery into the cervical spine may be solved by preoperative contrast administration. The method is susceptible to metal artifacts and, therefore, should be applied before metal implants are placed.}, language = {en} }