[Neuroendocrine tumors of the pancreas]. / Neuroendokrine Tumoren des Pankreas.

CLINICAL/METHODOLOGICAL ISSUE: Neuroendocrine tumors (NET) of the pancreas fall into the group of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN). The assignment of imaging morphological criteria to this heterogeneous group of complex tumors is often difficult. STANDARD RADIOLOGICAL METHODS: Diagnostic ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography-CT (PET/CT) are available for the detection of pancreatic NET (also referred to as NEN) and for the diagnosis of spread and the search for metastases. METHODOLOGICAL INNOVATIONS: In particular, nuclear medicine examination methods with somatostatin analogues are of high value, since they make tumors visible with high sensitivity via radioactively labeled receptor ligands. PERFORMANCE: CT and MRI have high detection rates of pancreatic NET. Further developments, such as diffusion imaging, have further improved these traditional cross-sectional imaging diagnostics. However, nuclear medicine methods are an important component in detection and are superior to CT and MRI. ACHIEVEMENTS: It is important for the radiologist to be familiar with NET of the pancreas, as it is an important differential diagnosis-also with regard to prognosis-of other pancreatic lesions. PRACTICAL RECOMMENDATIONS: Because NET are often hypervascularized, a biphasic examination technique after contrast administration is mandatory for cross-sectional imaging. PET/CT with somatostatin analogues should be performed for further diagnosis.

[Is there an unmet need to establish a young talent section "Young DGN" within the German Society of Nuclear Medicine (DGN)? - Results of a 2021/2022 web-based survey among German Nuclear Medicine professionals]. / Besteht der Bedarf zur Gründung einer Nachwuchsorganisation "Young DGN" innerhalb der Deutschen Gesellschaft für Nuklearmedizin (DGN)? Ergebnisse einer webbasierten Umfrage in der deutschen Nuklearmedizin 2021/2022.

AIM: In various medical societies, dedicated young talent sections provide an important basis for promoting young members. However, the German Society of Nuclear Medicine (DGN) had not yet implemented such a section. Therefore, the aim of this work was to assess the opinion of nuclear medicine professionals in Germany on establishing a young talent section within the DGN ("Young DGN"). METHODS: An initiative group of young DGN members developed a survey questionnaire comprising 18 questions. The questionnaire was initially sent as a PDF to the members of the DGN University Committee (Hochschulausschuss) by e-mail on 10/12/2021. As an online survey, the questionnaire was then emailed at four additional time points between 12/23/2021 and 3/18/2022 via the DGN eBrief and on 2/23/2022 to the members of the mailing list of the Berufsverband Deutscher Nuklearmediziner (BDN). RESULTS: The survey closed on 3/31/2022 with 111 responses (n=104 online surveys, n=7 PDFs). The median age of participants was 32.5 years (range, 20-80). 86% of participants indicated that they were interested in a Young DGN section, of which 67% were willing to participate. 79% indicated that nuclear medicine was an exciting field for them. 96% expressed interest in additional education offers and 60% in the establishment of a mentoring program. 75% believed that Young DGN would improve the visibility of the specialty. CONCLUSION: The survey results indicate strong support for the establishment of a young talent section within the DGN among nuclear medicine professionals in Germany. A large proportion of those who participated in the survey would envision active involvement. There was a particular consensus on the desire to expand the range of education and training activities.

Therapeutic window of bradykinin B2 receptor inhibition after focal cerebral ischemia in rats.

Following cerebral ischemia bradykinin/kinin B(2) receptors mediate inflammatory responses resulting in edema formation and secondary brain damage. However, the therapeutic window for B(2) receptor inhibition determining its potential clinical use has not been investigated so far. The aim of the current study was therefore to investigate the effect of delayed B(2) receptor inhibition on morphological and functional outcome following experimental stroke. Rats were subjected to 90 min of middle cerebral artery occlusion (MCAo) by an intraluminal filament. Animals received 0.9% NaCl or 1.0mg/kg/day Anatibant (LF 16-0687 Ms), a selective bradykinin B(2) receptor antagonist, for 3 days beginning at different time points after MCAo: 1, 2.5, 4.5, or 6.5h (n=10 per group). Neurological recovery was examined daily, infarct volume on day 7 after MCAo. Animal physiology was not influenced by B(2) receptor inhibition. Significant improvement of functional outcome was observed when treatment was delayed up to 4.5h after ischemia (p<0.05 versus vehicle). Inhibition of B(2) receptors during ischemia, i.e. when the inhibitor was given 1h after MCAo, reduced infarct volume in the basal ganglia and in the cortex by 49% (p<0.05) and 26% (p<0.05), respectively. Inhibition of B(2) receptors at later time points (2.5, 4.5, or 6.5 after MCAo) reduced penumbral damage, i.e. cortical infarction, by 19-26% (p<0.05). In conclusion, the current study shows that the therapeutic window of B(2) receptor inhibition extends for up to 6.5h after MCAo. Our data therefore suggest that inhibition of kinin B(2) receptors represents a treatment strategy for ischemic stroke which may warrant clinical validation.

(18)F-Fluoroethyl-l-Thyrosine Positron Emission Tomography to Delineate Tumor Residuals After Glioblastoma Resection: A Comparison with Standard Postoperative Magnetic Resonance Imaging.

OBJECTIVE: Complete resection of contrast-enhancing tumor is an important prognostic factor in glioblastoma therapy. The current clinical standard for control of resection is magnetic resonance imaging (MRI). (18)F-Fluoroethyl-l-thyrosine (FET) is a positron emission tomography (PET) radiopharmaceutical applicable for widespread use because of its long half-life radionuclide. We assessed the sensitivity of postoperative MRI versus FET-PET to detect residual tumor and the impact of the time interval between resection and FET-PET. METHODS: MRI and FET-PET were performed preoperatively and postoperatively in 62 patients undergoing 63 operations. FET-PET was performed in 43 cases within 72 hours after resection and in 20 cases >72 hours after resection. Detection and measurement of volume of residual tumors were compared. Correlations between residual tumor detection and timing of PET after resection and recurrence were examined. RESULTS: Complete resection was confirmed by both imaging modalities in 44% of cases, and residual tumor was detected consistently in 37% of cases. FET-PET detected residual tumor in 14% of cases in which MRI showed no residual tumor. MRI showed residual tumors in 5% of cases that were not identified by PET. Average PET-based residual tumor volume was higher than MRI-based volume (3.99 cm(3) vs. 1.59 cm(3)). Detection of and difference in volume of residual tumor were not correlated with timing of PET after resection or recurrence status. CONCLUSIONS: Postoperative FET-PET revealed residual tumor with higher sensitivity than MRI and showed larger tumor volumes. In this series, performing PET >72 hours after resection did not influence the results of PET. We recommend FET-PET as a helpful adjunct in addition to MRI for postoperative assessment of residual tumor.

Early [18F]FET-PET in Gliomas after Surgical Resection: Comparison with MRI and Histopathology.

BACKGROUND: The precise definition of the post-operative resection status in high-grade gliomas (HGG) is crucial for further management. We aimed to assess the feasibility of assessment of the resection status with early post-operative positron emission tomography (PET) using [18F]O-(2-[18F]-fluoroethyl)-L-tyrosine ([18F]FET). METHODS: 25 patients with the suspicion of primary HGG were enrolled. All patients underwent pre-operative [18F]FET-PET and magnetic resonance imaging (MRI). Intra-operatively, resection status was assessed using 5-aminolevulinic acid (5-ALA). Imaging was repeated within 72 h after neurosurgery. Post-operative [18F]FET-PET was compared with MRI, intra-operative assessment and clinical follow-up. RESULTS: [18F]FET-PET, MRI and intra-operative assessment consistently revealed complete resection in 12/25 (48%) patients and incomplete resection in 6/25 cases (24%). In 7 patients, PET revealed discordant findings. One patient was re-resected. 3/7 experienced tumor recurrence, 3/7 died shortly after brain surgery. CONCLUSION: Early assessment of the resection status in HGG with [18F]FET-PET seems to be feasible.