392 research outputs found

    InterviewgestĂźtzte Evaluation von Umweltbildungsveranstaltungen fĂźr Biolandwirte

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    This paper discusses the effects of environmental education for organic farmers on the implementation of conservation measurements in farm management. By means of a telephone survey, a sample of 62 farmers was interviewed to evaluate the success of an education program, which consisted of theoretical lectures in winter as well as excursions in summer. The results of the interviews prove a positive feedback of farmers on the environmental education. However, concerning implementation of more comprehensive nature conservation measures appropriate (agricultural) political and financial frame conditions are essential

    Primary Carcinoid Tumor of the Skull Base: Case Report and Review of the Literature

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    We present an unusual case of primary intracranial carcinoid tumor of the skull base centered at the level of the foramen jugulare, which was proven with surgical biopsy and later with Somatostatin receptor nuclear medicine scan. We present the salient magnetic resonance imaging features of this rare tumor, describe their characteristic nuclear medicine findings, and briefly review the literature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79329/1/j.1552-6569.2008.00317.x.pd

    Feasibility of simultaneous PET/MR imaging in the head and upper neck area

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    Objective: The aim of this pilot study was to test and demonstrate the feasibility of simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) of the head and upper neck area using a new hybrid PET/MRI system. Methods: Eight patients with malignant head and neck tumours were included in the pilot study. Directly after routine PET/CT imaging with a whole-body system using the glucose derivative 2-[18F]fluoro-2deoxy-D-glucose (FDG) as a radiotracer additional measurements were performed with a prototype PET/MRI system for simultaneous PET and MR imaging. Physiological radiotracer uptake within regular anatomical structures as well as tumour uptake were evaluated visually and semiquantitatively (metabolic ratios) in relation to cerebellar uptake on the PET/MRI and PET/CT systems. Results: The MR datasets showed excellent image quality without any recognisable artefacts caused by the inserted PET system. PET images obtained with the PET/MRI system exhibited better detailed resolution and greater image contrast in comparison to those from the PET/CT system. An excellent agreement between metabolic ratios obtained with both PET systems was found: R = 0.99 for structures with physiological tracer uptake, R = 0.96 for tumours. Conclusion: Simultaneous PET/MRI of the head and upper neck area is feasible with the new hybrid PET/MRI prototyp

    [68Ga]-DOTATOC-PET/CT for meningioma IMRT treatment planning

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    <p>Abstract</p> <p>Purpose</p> <p>The observation that human meningioma cells strongly express somatostatin receptor (SSTR 2) was the rationale to analyze retrospectively in how far DOTATOC PET/CT is helpful to improve target volume delineation for intensity modulated radiotherapy (IMRT).</p> <p>Patients and Methods</p> <p>In 26 consecutive patients with preferentially skull base meningioma, diagnostic magnetic resonance imaging (MRI) and planning-computed tomography (CT) was complemented with data from [<sup>68</sup>Ga]-DOTA-D Phe<sup>1</sup>-Tyr<sup>3</sup>-Octreotide (DOTATOC)-PET/CT. Image fusion of PET/CT, diagnostic computed tomography, MRI and radiotherapy planning CT as well as target volume delineation was performed with OTP-Masterplan<sup>ÂŽ</sup>. Initial gross tumor volume (GTV) definition was based on MRI data only and was secondarily complemented with DOTATOC-PET information. Irradiation was performed as EUD based IMRT, using the Hyperion Software package.</p> <p>Results</p> <p>The integration of the DOTATOC data led to additional information concerning tumor extension in 17 of 26 patients (65%). There were major changes of the clinical target volume (CTV) which modify the PTV in 14 patients, minor changes were realized in 3 patients. Overall the GTV-MRI/CT was larger than the GTV-PET in 10 patients (38%), smaller in 13 patients (50%) and almost the same in 3 patients (12%). Most of the adaptations were performed in close vicinity to bony skull base structures or after complex surgery. Median GTV based on MRI was 18.1 cc, based on PET 25.3 cc and subsequently the CTV was 37.4 cc. Radiation planning and treatment of the DOTATOC-adapted volumes was feasible.</p> <p>Conclusion</p> <p>DOTATOC-PET/CT information may strongly complement patho-anatomical data from MRI and CT in cases with complex meningioma and is thus helpful for improved target volume delineation especially for skull base manifestations and recurrent disease after surgery.</p

    Cancer immunotherapy is accompanied by distinct metabolic patterns in primary and secondary lymphoid organs observed by non-invasive in vivo18F-FDG-PET

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    Purpose: Cancer immunotherapy depends on a systemic immune response, but the basic underlying mechanisms are still largely unknown. Despite the very successful and widespread use of checkpoint inhibitors in the clinic, the majority of cancer patients do not benefit from this type of treatment. In this translational study, we investigated whether noninvasive in vivo positron emission tomography (PET) imaging using 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) is capable of detecting immunotherapy-associated metabolic changes in the primary and secondary lymphoid organs and whether this detection enables the prediction of a successful anti-cancer immune response. Methods: RIP1-Tag2 mice with progressed endogenous insular cell carcinomas underwent a combined cancer immunotherapy consisting of CD4+ T cells plus monoclonal antibodies (mAbs) against programmed death ligand-1 (PD-L1) and lymphocyte activation gene-3 (LAG-3) or a sham treatment after radiation-mediated immune cell depletion. A second cohort of RIP1-Tag2 mice underwent exclusive checkpoint inhibitor therapy (CIT) using anti-PD-L1/LAG-3 mAbs or sham treatment without initial immune cell depletion to mimic the clinical situation. All mice were monitored by 18F-FDG-PET combined with anatomical magnetic resonance imaging (MRI). In addition, we retrospectively analyzed PET / computed tomography (CT) scans (PET/CT) regarding 18F-FDG uptake of CIT-treated metastatic melanoma patients in the spleen (n=23) and bone marrow (BM; n=20) as well as blood parameters (n=17-21). Results: RIP1-Tag2 mice with advanced insular cell carcinomas treated with combination immunotherapy exhibited significantly increased 18F-FDG uptake in the spleen compared to sham-treated mice. Histopathology of the spleens from treated mice revealed atrophy of the white pulp with fewer germinal centers and an expanded red pulp with hyperplasia of neutrophils than those of sham-treated mice. Immunohistochemistry and flow cytometry analyses of the spleens revealed a lower number of T cells and a higher number of neutrophils compared to those in the spleens of sham-treated mice. Flow cytometry of the BM showed enhanced activation of T cells following the treatment schemes that included checkpoint inhibitors. The ratio of 18F-FDG uptake at baseline to the uptake at follow-up in the spleens of exclusively CIT-treated RIP1-Tag2 mice was significantly enhanced, but the ratio was not enhanced in the spleens of the sham-treated littermates. Flow cytometry analysis confirmed a reduced number of T cells in the spleens of exclusively CIT-treated mice compared to that of sham-treated mice. A retrospective analysis of clinical 18F-FDG-PET/CT scans revealed enhanced 18F-FDG uptake in the spleens of some successfully CIT-treated patients with metastatic melanoma, but there were no significant differences between responders and non-responders. The analysis of the BM in clinical 18F-FDG-PET/CT scans with a computational segmentation tool revealed significantly higher baseline 18F-FDG uptake in patients who responded to CIT than in non-responders, and this relationship was independent of bone metastasis, even in the baseline scan. Conclusions: Thus, we are presenting the first translational study of solid tumors focusing on the metabolic patterns of primary and secondary lymphoid organs induced by the systemic immune response after CIT. We demonstrate that the widely available 18F-FDG-PET modality is an applicable translational tool that has high potential to stratify patients at an early time point

    Prognostic Value of [18F]-Fluoro-Deoxy-Glucose PET/CT, S100 or MIA for Assessment of Cancer-Associated Mortality in Patients with High Risk Melanoma

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    PURPOSE: To assess the prognostic value of FDG PET/CT compared to the tumor markers S100B and melanoma inhibitory activity (MIA) in patients with high risk melanoma. METHODS: Retrospective study in 125 consecutive patients with high risk melanoma that underwent FDG PET/CT for re-staging. Diagnostic accuracy and prognostic value was determined for FDG PET/CT as well as for S100B and MIA. As standard of reference, cytological, histological, PET/CT or MRI follow-up findings as well as clinical follow-up were used. RESULTS: Of 125 patients, FDG PET/CT was positive in 62 patients. 37 (29.6%) patients had elevated S100B (>100 pg/ml) and 24 (20.2%) had elevated MIA (>10 pg/ml) values. Overall specificities for FDG PET/CT, S100B and MIA were 96.8% (95% CI, 89.1% to 99.1%), 85.7% (75.0% to 92.3%), and 95.2% (86.9% to 98.4%), corresponding sensitivities were 96.8% (89.0% to 99.1%), 45.2% (33.4% to 55.5%), and 36.1% (25.2% to 48.6%), respectively. The negative predictive values (NPV) for PET/CT, S100B, and MIA were 96.8% (89.1% to 99.1%), 61.4% (50.9% to 70.9%), and 60.6% (50.8% to 69.7%). The positive predictive values (PPV) were 96.7% (89.0% to 99.1%), 75.7% (59.9% to 86.6%), and 88.0% (70.0% to 95.8%). Patients with elevated S100B- or MIA values or PET/CT positive findings showed a significantly (p<0.001 each, univariate Cox regression models) higher risk of melanoma associated death which was increased 4.2-, 6.5- or 17.2-fold, respectively. CONCLUSION: PET/CT has a higher prognostic power in the assessment of cancer-associated mortality in melanoma patients compared with S100 and MIA
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