TY - JOUR A1 - Lapa, Constantin A1 - Lückerath, Katharina A1 - Kleinlein, Irene A1 - Monoranu, Camelia Maria A1 - Linsenmann, Thomas A1 - Kessler, Almuth F. A1 - Rudelius, Martina A1 - Kropf, Saskia A1 - Buck, Andreas K. A1 - Ernestus, Ralf-Ingo A1 - Wester, Hans-Jürgen A1 - Löhr, Mario A1 - Herrmann, Ken T1 - \(^{68}\)Ga-Pentixafor-PET/CT for Imaging of Chemokine Receptor 4 Expression in Glioblastoma JF - Theranostics N2 - 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. KW - imaging KW - chemokine receptor-4 KW - glioblastoma KW - positron emission tomography/computed tomography KW - \(^{68}\)Ga-Pentixafor Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168174 VL - 6 IS - 3 ER - TY - JOUR A1 - Canessa, Andrea A1 - Pozzi, Nicolò G. A1 - Arnulfo, Gabriele A1 - Brumberg, Joachim A1 - Reich, Martin M. A1 - Pezzoli, Gianni A1 - Ghilardi, Maria F. A1 - Matthies, Cordula A1 - Steigerwald, Frank A1 - Volkmann, Jens A1 - Isaias, Ioannis U. T1 - Striatal Dopaminergic Innervation Regulates Subthalamic Beta-Oscillations and Cortical-Subcortical Coupling during Movements: Preliminary Evidence in Subjects with Parkinson's Disease JF - Frontiers in Human Neuroscience N2 - Activation of the basal ganglia has been shown during the preparation and execution of movement. However, the functional interaction of cortical and subcortical brain areas during movement and the relative contribution of dopaminergic striatal innervation remains unclear. We recorded local field potential (LFP) activity from the subthalamic nucleus (STN) and high-density electroencephalography (EEG) signals in four patients with Parkinson’s disease (PD) off dopaminergic medication during a multi-joint motor task performed with their dominant and non-dominant hand. Recordings were performed by means of a fully-implantable deep brain stimulation (DBS) device at 4 months after surgery. Three patients also performed a single-photon computed tomography (SPECT) with [123I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane (FP-CIT) to assess striatal dopaminergic innervation. Unilateral movement execution led to event-related desynchronization (ERD) followed by a rebound after movement termination event-related synchronization (ERS) of oscillatory beta activity in the STN and primary sensorimotor cortex of both hemispheres. Dopamine deficiency directly influenced movement-related beta-modulation, with greater beta-suppression in the most dopamine-depleted hemisphere for both ipsi- and contralateral hand movements. Cortical-subcortical, but not interhemispheric subcortical coherencies were modulated by movement and influenced by striatal dopaminergic innervation, being stronger in the most dopamine-depleted hemisphere. The data are consistent with a role of dopamine in shielding subcortical structures from an excessive cortical entrapment and cross-hemispheric coupling, thus allowing fine-tuning of movement. KW - beta oscillations KW - Parkinson’s disease KW - motor control KW - movement disorders KW - imaging KW - subthalamic nucleus KW - coherence analysis Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164061 VL - 10 IS - 611 ER - TY - JOUR A1 - Hendricks, Anne A1 - Lenschow, Christina A1 - Kroiss, Matthias A1 - Buck, Andreas A1 - Kickuth, Ralph A1 - Germer, Christoph-Thomas A1 - Schlegel, Nicolas T1 - Evaluation of diagnostic efficacy for localization of parathyroid adenoma in patients with primary hyperparathyroidism undergoing repeat surgery JF - Langenbeck's Archives of Surgery N2 - Purpose Repeat surgery in patients with primary hyperparathyroidism (pHPT) is associated with an increased risk of complications and failure. This stresses the need for optimized strategies to accurately localize a parathyroid adenoma before repeat surgery is performed. However, evidence on the extent of required diagnostics for a structured approach is sparse. Methods A retrospective single-center evaluation of 28 patients with an indication for surgery due to pHPT and previous thyroid or parathyroid surgery was performed. Diagnostic workup, surgical approach, and outcome in terms of complications and successful removement of parathyroid adenoma with biochemical cure were evaluated. Results Neck ultrasound, sestamibi scintigraphy, C11-methionine PET-CT, and selective parathyroid hormone venous sampling, but not MRI imaging, effectively detected the presence of a parathyroid adenoma with high positive predictive values. Biochemical cure was revealed by normalization of calcium and parathormone levels 24-48h after surgery and was achieved in 26/28 patients (92.9%) with an overall low rate of complications. Concordant localization by at least two diagnostic modalities enabled focused surgery with success rates of 100%, whereas inconclusive localization significantly increased the rate of bilateral explorations and significantly reduced the rate of biochemical cure to 80%. Conclusion These findings suggest that two concordant diagnostic modalities are sufficient to accurately localize parathyroid adenoma before repeat surgery for pHPT. In cases of poor localization, extended diagnostic procedures are warranted to enhance surgical success rates. We suggest an algorithm for better orientation when repeat surgery is intended in patients with pHPT. KW - Primary hyperparathyroidism (pHPT) KW - preoperative localization KW - repeat surgery KW - diagnostics KW - imaging Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267520 SN - 1435-2451 VL - 406 IS - 5 ER -