10 results on '"Cyran, Clemens"'
Search Results
2. Diagnostic performance of PET/CT in the detection of liver metastases in well-differentiated NETs
- Author
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Grawe, Freba, Rosenberger, Natalie, Ingenerf, Maria, Beyer, Leonie, Eschbach, Ralf, Todica, Andrei, Seidensticker, Ricarda, Schmid-Tannwald, Christine, Cyran, Clemens C., Ricke, Jens, Bartenstein, Peter, Auernhammer, Christoph. J., Ruebenthaler, Johannes, and Fabritius, Matthias P.
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- 2023
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3. Dosimetry and optimal scan time of [18F]SiTATE-PET/CT in patients with neuroendocrine tumours
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Beyer, Leonie, Gosewisch, Astrid, Lindner, Simon, Völter, Friederike, Mittlmeier, Lena M., Tiling, Reinhold, Brendel, Matthias, Cyran, Clemens C., Unterrainer, Marcus, Rübenthaler, Johannes, Auernhammer, Christoph J., Spitzweg, Christine, Böning, Guido, Gildehaus, F. J., Jurkschat, Klaus, Wängler, Carmen, Wängler, Björn, Schirrmacher, Ralf, Wenter, Vera, Todica, Andrei, Bartenstein, Peter, and Ilhan, Harun
- Published
- 2021
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4. The Radiologist’s Approach to CUP
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Kazmierczak, Philipp M., Rominger, Axel, Cyran, Clemens C., Krämer, Alwin, editor, and Löffler, Harald, editor
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- 2016
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5. The diagnostic value of [18F]FDG PET for the detection of chronic osteomyelitis and implant-associated infection
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Wenter, Vera, Müller, Jan-Phillip, Albert, Nathalie L., Lehner, Sebastian, Fendler, Wolfgang P., Bartenstein, Peter, Cyran, Clemens C., Friederichs, Jan, Militz, Matthias, Hacker, Marcus, and Hungerer, Sven
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- 2016
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6. Comparison of somatostatin receptor expression in patients with neuroendocrine tumours with and without somatostatin analogue treatment imaged with [18F]SiTATE.
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Eschbach, Ralf S., Hofmann, Markus, Späth, Lukas, Sheikh, Gabriel T., Delker, Astrid, Lindner, Simon, Jurkschat, Klaus, Wängler, Carmen, Wängler, Björn, Schirrmacher, Ralf, Tiling, Reinhold, Brendel, Matthias, Wenter, Vera, Dekorsy, Franziska J., Zacherl, Mathias J., Todica, Andrei, Ilhan, Harun, Grawe, Freba, Cyran, Clemens C., and Unterrainer, Marcus
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SOMATOSTATIN receptors ,NEUROENDOCRINE tumors ,SOMATOSTATIN ,POSITRON emission tomography ,ADRENAL glands - Abstract
Purpose: Somatostatin analogues (SSA) are frequently used in the treatment of neuroendocrine tumours. Recently, [
18 F]SiTATE entered the field of somatostatin receptor (SSR) positron emission tomography (PET)/computed tomography (CT) imaging. The purpose of this study was to compare the SSR-expression of differentiated gastroentero-pancreatic neuroendocrine tumours (GEP-NET) measured by [18 F]SiTATE-PET/CT in patients with and without previous treatment with long-acting SSAs to evaluate if SSA treatment needs to be paused prior to [18 F]SiTATE-PET/CT. Methods: 77 patients were examined with standardised [18 F]SiTATE-PET/CT within clinical routine: 40 patients with long-acting SSAs up to 28 days prior to PET/CT examination and 37 patients without pre-treatment with SSAs. Maximum and mean standardized uptake values (SUVmax and SUVmean) of tumours and metastases (liver, lymphnode, mesenteric/peritoneal and bones) as well as representative background tissues (liver, spleen, adrenal gland, blood pool, small intestine, lung, bone) were measured, SUV ratios (SUVR) were calculated between tumours/metastases and liver, likewise between tumours/metastases and corresponding specific background, and compared between the two groups. Results: SUVmean of liver (5.4 ± 1.5 vs. 6.8 ± 1.8) and spleen (17.5 ± 6.8 vs. 36.7 ± 10.3) were significantly lower (p < 0.001) and SUVmean of blood pool (1.7 ± 0.6 vs. 1.3 ± 0.3) was significantly higher (p < 0.001) in patients with SSA pre-treatment compared to patients without. No significant differences between tumour-to-liver and specific tumour-to-background SUVRs were observed between both groups (all p > 0.05). Conclusion: In patients previously treated with SSAs, a significantly lower SSR expression ([18 F]SiTATE uptake) in normal liver and spleen tissue was observed, as previously reported for 68Ga-labelled SSAs, without significant reduction of tumour-to-background contrast. Therefore, there is no evidence that SSA treatment needs to be paused prior to [18 F]SiTATE-PET/CT. [ABSTRACT FROM AUTHOR]- Published
- 2023
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7. State of affairs of hybrid imaging in Europe: two multi-national surveys from 2017
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Gatidis, Sergios, Beyer, Thomas, Becker, Minerva, Riklund, Katrine, Nikolaou, Konstantin, Cyran, Clemens, and Pfannenberg, Christina
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lcsh:Medical physics. Medical radiology. Nuclear medicine ,PET ,Hybrid imaging ,PET/CT ,lcsh:R895-920 ,Training ,Original Article ,Radiologi och bildbehandling ,Survey ,Procedures ,ddc:616.0757 ,CT ,Radiology, Nuclear Medicine and Medical Imaging - Abstract
Objectives To assess the current state of hybrid imaging in Europe with respect to operations, reading and reporting, as well as qualification and training. Methods The first survey (LOCAL) was sent to the heads of the departments of radiology and nuclear medicine in Europe in 2017, including 15 questions regarding the organisation of hybrid imaging operations, reporting strategies for PET/CT and the existence of relevant training programmes. The second survey (NATIONAL) consisted of 10 questions and was directed to the national ministries of health of 37 European countries addressing combined training options in radiology and nuclear medicine. Results In the LOCAL survey, 61 valid responses from 26 European countries were received. In almost half of the institutions, hybrid imaging was performed within a single department, mainly in nuclear medicine departments (31%). In half of the centres (51%), PET/CT reports were performed jointly, while in 20% of the centres, reporting was performed by nuclear medicine physicians. Radiologists were responsible for presenting hybrid imaging results in clinical boards in 34% of responding sites. Integrated hybrid imaging training was available in 41% sites. In the NATIONAL survey, responses from 34 countries were received and demonstrated a heterogeneous landscape of official training possibilities in radiology and nuclear medicine with limited opportunities for additional qualifications in hybrid imaging. Conclusions The results of these surveys demonstrate a notable heterogeneity in the current practice of hybrid imaging throughout Europe. This heterogeneity exists despite the general consensus that strong professional cooperation is required in order to ensure high clinical quality and to strengthen the clinical role of hybrid imaging.
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- 2019
8. Dosimetry and optimal scan time of [18F]SiTATE-PET/CT in patients with neuroendocrine tumours.
- Author
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Beyer, Leonie, Gosewisch, Astrid, Lindner, Simon, Völter, Friederike, Mittlmeier, Lena M., Tiling, Reinhold, Brendel, Matthias, Cyran, Clemens C., Unterrainer, Marcus, Rübenthaler, Johannes, Auernhammer, Christoph J., Spitzweg, Christine, Böning, Guido, Gildehaus, F. J., Jurkschat, Klaus, Wängler, Carmen, Wängler, Björn, Schirrmacher, Ralf, Wenter, Vera, and Todica, Andrei
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NEUROENDOCRINE tumors ,RADIATION dosimetry ,SOMATOSTATIN receptors ,INJECTIONS ,ADULTS ,OPTICALLY stimulated luminescence - Abstract
Purpose: Radiolabelled somatostatin analogues targeting somatostatin receptors (SSR) are well established for combined positron emission tomography/computer tomography (PET/CT) imaging of neuroendocrine tumours (NET). [
18 F]SiTATE has recently been introduced showing high image quality, promising clinical performance and improved logistics compared to the clinical reference standard68 Ga-DOTA-TOC. Here we present the first dosimetry and optimal scan time analysis. Methods: Eight NET patients received a [18 F]SiTATE-PET/CT (250 ± 66 MBq) with repeated emission scans (10, 30, 60, 120, 180 min after injection). Biodistribution in normal organs and SSR-positive tumour uptake were assessed. Dosimetry estimates for risk organs were determined using a combined linear-monoexponential model, and by applying18 F S-values and reference target masses for the ICRP89 adult male or female (OLINDA 2.0). Tumour-to-background ratios were compared quantitatively and visually between different scan times. Results: After 1 h, normal organs showed similar tracer uptake with only negligible changes until 3 h post-injection. In contrast, tracer uptake by tumours increased progressively for almost all types of metastases, thus increasing tumour-to-background ratios over time. Dosimetry resulted in a total effective dose of 0.015 ± 0.004 mSv/MBq. Visual evaluation revealed no clinically relevant discrepancies between later scan times, but image quality was rated highest in 60 and 120 min images. Conclusion: [18 F]SiTATE-PET/CT in NET shows overall high tumour-to-background ratios from 60 to 180 min after injection and an effective dose comparable to68 Ga-labelled alternatives. For clinical use of [18 F]SiTATE, the best compromise between image quality and tumour-to-background contrast is reached at 120 min, followed by 60 min after injection. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
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9. The diagnostic value of [F]FDG PET for the detection of chronic osteomyelitis and implant-associated infection.
- Author
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Wenter, Vera, Müller, Jan-Phillip, Albert, Nathalie, Lehner, Sebastian, Fendler, Wolfgang, Bartenstein, Peter, Cyran, Clemens, Friederichs, Jan, Militz, Matthias, Hacker, Marcus, and Hungerer, Sven
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POSITRON emission tomography ,OSTEOMYELITIS diagnosis ,MEDICAL decision making ,ORTHOPEDIC implant complications ,ORTHOPEDIC surgery - Abstract
Purpose: The diagnosis of osteomyelitis and implant-associated infections in patients with nonspecific laboratory or radiological findings is often unsatisfactory. We retrospectively evaluated the contributions of [F]FDG PET and [F]FDG PET/CT to the diagnosis of osteomyelitis and implant-associated infections, enabling timely and appropriate decision-making for further therapy options. Methods: [F]FDG PET or PET/CT was performed in 215 patients with suspected osteomyelitis or implant-associated infections between 2000 and 2013. We assessed the diagnostic accuracy of both modalities together and separately with reference to intraoperative microbial findings, with a mean clinical follow-up of 69 ± 49 months. Results: Infections were diagnosed clinically in 101 of the 215 patients. PET and PET/CT scans revealed 87 true-positive, 76 true-negative, 38 false-positive, and 14 false-negative results, indicating a sensitivity of 86 %, a specificity of 67 %, a positive predictive value (PPV) of 70 %, a negative predictive value (NPV) of 84 % and an accuracy of 76 %. The sensitivity of PET/CT was 88 %, but specificity, PPV, NPV and accuracy (76 %, 76 %, 89 % and 82 %, respectively) were higher than those of stand-alone PET. Conclusion: [F]FDG PET is able to identify with high sensitivity the presence of osteomyelitis in orthopaedic surgery patients with nonspecific clinical symptoms of infection. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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10. Supplemental 18 F-FDG-PET/CT for Detection of Malignant Transformation of IPMN—A Model-Based Cost-Effectiveness Analysis.
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Bicu, Felix, Rink, Johann S., Froelich, Matthias F., Cyran, Clemens C., Rübenthaler, Johannes, Birgin, Emrullah, Röhrich, Manuel, Tollens, Fabian, and Peulen, Olivier
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TUMOR diagnosis ,PANCREATIC tumors ,MAGNETIC resonance imaging ,COST control ,POSITRON emission tomography ,COST effectiveness ,RADIOPHARMACEUTICALS ,COMPUTED tomography ,DEOXY sugars ,QUALITY-adjusted life years - Abstract
Simple Summary: The incidence of IPMN is increasing, mainly attributed to the expanded application of radiological cross-sectional imaging and improvements in image quality. IPMN are the cause of approximately 10% of all pancreatectomies in the USA. A significant number of surgically treated IPMNs do not show high-grade dysplasia or invasive cancer, raising the question of overtreatment, and the need for better diagnostic accuracy.
18 F-FDG-PET/CT demonstrated promising diagnostic performance in the detection of malignant transformation of IPMN in comparison to CT and MRI. In this study, the authors analyze whether a supplemental18 F-FDG-PET/CT to the current diagnostic pathway of IPMN could be cost-effective. Results suggest that implementation of18 F-FDG-PET/CT in a preoperative setting could be beneficial from a health care system perspective. It also encourages the research community to investigate if18 F-FDG-PET/CT could be a useful addition in other diagnostic settings within IPMN management. Accurate detection of malignant transformation and risk-stratification of intraductal papillary mucinous neoplasms (IPMN) has remained a diagnostic challenge. Preliminary findings have indicated a promising role of positron emission tomography combined with computed tomography and18 F-fluorodeoxyglucose (18 F-FDG-PET/CT) in detecting malignant IPMN. Therefore, the aim of this model-based economic evaluation was to analyze whether supplemental FDG-PET/CT could be cost-effective in patients with IPMN. Decision analysis and Markov modeling were applied to simulate patients' health states across a time frame of 15 years. CT/MRI based imaging was compared to a strategy with supplemental18 F-FDG-PET/CT. Cumulative costs in US-$ and outcomes in quality-adjusted life years (QALY) were computed based on input parameters extracted from recent literature. The stability of the model was evaluated by deterministic sensitivity analyses. In the base-case scenario, the CT/MRI-strategy resulted in cumulative discounted costs of USD $106,424 and 8.37 QALYs, while the strategy with supplemental FDG-PET/CT resulted in costs of USD $104,842 and a cumulative effectiveness of 8.48 QALYs and hence was cost-saving. A minimum specificity of FDG-PET/CT of 71.5% was required for the model to yield superior net monetary benefits compared to CT/MRI. This model-based economic evaluation indicates that supplemental18 F-FDG-PET/CT could have a favorable economic value in the management of IPMN and could be cost-saving in the chosen setting. Prospective studies with standardized protocols for FDG-PET/CT could help to better determine the value of FDG-PET/CT. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
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