Ziel/Aim Mit der Einführung des SPECT/CT konnten jodspeichernde Lymphknotenmetastasen (LKM) in der Bildgebung nach therapeutischer Jodgabe besser und sicherer detektiert werden (1). Im kurzfristigen Verlauf wurden über 90 % der Metastasen < 0.9 ml und 50 % der Metastasen > 0.9 ml mit Radiojod erfolgreich therapiert (2). Ziel dieser Studie war es, den weiteren Verlauf bei den Patienten mit jodspeichernden Metastasen bei Ersttherapie zu prüfen und zu klären, ob sich eine erfolgreiche Therapie im 5 Monatsverlauf auch nach 5 Jahren und länger bestätigt.

Aus der Literatur ist bekannt, dass der Uptake von Tc-99 m-DPD im gesunden Knochen mit der Knochendichte korreliert [1]. Ziel dieser Studie war es, zu untersuchen, ob die Korrelation von Knochenstoffwechsel und Knochendichte auch in Knochenmetastasen vorliegt.

SPECT/CT detects radioiodine-positive cervical lymph node metastases (LNMs) of differentiated thyroid carcinoma (DTC) at the time of postsurgical radioablation (RA). Preliminary evidence indicates that the majority of LNMs are successfully treated by RA. The aim of this study was to confirm this evidence in a bicentric setting and to evaluate whether size is a predictor for successful elimination. Patients and methods: Since 01/2007 and 05/2008, respectively, SPECT/spiral-CT is performed routinely in all patients with DTC at RA in two University Clinics. The outcome of iodine-positive LNMs identified by SPECT/CT until 12/2012 was analyzed by follow-up diagnostic 131I scans and serum thyreoglobulin (Tg) values. LNM volume and short-axis diameter were evaluated as prognostic factors by a receiver-operating characteristic (ROC) analysis. Results: 79 patients with 97 iodine-positive LNMs were included. Surgery was carried out in 8 patients with 13 LNMs due to the presence of additional iodine-negative lesions. Of the remaining 84 LNMs, 74 (88%) were successfully treated as demonstrated by radioiodine scans at follow-up. 10 LNMs persisted. 67/70 LNMs smaller than 0.9 ml were treated successfully, whereas this was the case of only 6/14 exceeding this threshold. Using this cut-off level to predict treatment success, sensitivity, specificity, positive and negative predictive value were 92%, 73%, 96%, and 57%. Results for short-axis diameter (cut-off level < 1cm) were 90%, 69%, 94% and 56%. Conclusion: RA is effective in the treatment of the majority of 131I-positive LNMs identified in SPECT/CT images. In this study, 88% of iodine-positive LNM in DTC were successfully treated by radioiodine given at RA. Both LNM volume and diameter are reliable predictors of treatment success.

This document describes the guideline for peptide receptor radionuclide therapy (PRRT) published by the German Society of Nuclear Medicine (DGN) and accepted by the Association of the Scientific Medical Societies in Germany (AWMF) to be included in the official AWMF Guideline Registry. These recommendations are a prerequisite for the quality management in the treatment of patients with somatostatin receptor expressing tumours using PRRT. They are aimed at guiding nuclear medicine specialists in selecting likely candidates to receive PRRT and to deliver the treatment in a safe and effective manner. The recommendations are based on an interdisciplinary consensus. The document contains background information and definitions and covers the rationale, indications and contraindications for PRRT. Essential topics are the requirements for institutions performing the therapy, e.g. presence of an expert for medical physics, intense cooperation with all colleagues involved in the treatment of a patient, and a certificate of instruction in radiochemical labelling and quality control are required. Furthermore, it is specified which patient data have to be available prior to performance of therapy and how treatment has to be carried out technically. Here, quality control and documentation of labelling are of great importance. After treatment, clinical quality control is mandatory (work-up of therapy data and follow-up of patients). Essential elements of follow-up are specified in detail. The complete treatment inclusive after-care has to be realised in close cooperation with the involved medical disciplines. Generally, the decision for PRRT should be undertaken within the framework of a multi-disciplinary tumour board.

ZusammenfassungDiese Handlungsempfehlung soll eine Grundlage für die Qualitätssicherung der Peptid - rezeptor-Radionuklidtherapie (PRRT) von Patienten mit Somatostatinrezeptor-exprimierenden Tumoren schaffen, die zurzeit in Deutschland bei fehlenden gleichwertigen oder besseren Therapiealternativen im Rahmen eines individuellen Heilversuches erfolgt. Sie wurde interdisziplinär erarbeitet und enthält neben Definition, allgemeiner Zielsetzung und klinischen Hintergrundinformationen Angaben zu Indikationen und Kontraindikationen der PRRT. Im Mittelpunkt stehen die Anforderungen, die an das Behandlungszentrum gestellt werden, wie die enge Zusammenarbeit der an der Behandlung beteiligten Fachgebiete. Weiterhin wird spezifiziert, welche Untersuchungsbefunde vor der Therapie vorliegen müssen und wie die PRRT technisch und organisatorisch durchzuführen ist. Nach der Behandlung ist eine langfristige Nachsorge/Kontrolle der therapierten Patienten – u. a. zur Gewinnung onkologischer Qualitätsparameter – unabdingbar. Die gesamte Behandlung einschließlich der Nachsorge muss in enger Abstimmung und Zusammenarbeit der beteiligten Fachdisziplinen erfolgen, wobei in der Regel die Empfehlung zur PRRT durch ein multidisziplinäres Tumorboard erfolgen sollte.

362 Objectives Up to now the management of radioiodine-positive lymph node metastases (LNMs) identified by SPECT/CT in patients with thyroid carcinoma (DTC) at first radioablation (RA) is not clearly defined. The detection of LNMs could, e.g., prompt surgical reintervention. However, radioiodine-positive LNM might not survive radioablation so that reoperation could represent an overtreatment. The purpose of this study was to investigate the clinical outcome of patients with such radioiodine-positive LNMs. Methods At the Clinics of Nuclear Medicine of the Ludwig-Maximilians-University of Munich and the Friedrich-Alexander-University of Erlangen-Nuremberg SPECT/spiral-CT is routinely performed in all subjects with DTC at the time of RA. Screening the SPECT/CT databases for DTC patients produced 65 patients with 77 lymph node metastases identified by SPECT/CT at RA after thyroidectomy. 8 patients with 13 LNMs underwent surgery to remove LNMs due to the presence of additional suspicious iodine-negative LNMs and were removed from further analysis. Follow-up was available in 57 patients (papillary 48/ follicular 8/ insular 1; staging: 27 pT1, 9 pT2, 21 pT3,; 21 pN1, 36 pNx or 0) and included the measurement of serum thyreoglobulin (Tg) values and diagnostic I-131 scans. Results 49 patients with 55 LNMs were successfully treated by radioiodine as demonstrated by negative radioiodine scans and Tg values at follow-up. 9 LNMs persisted and 8 new LNMs were detected at follow-up. 50/53 LNMs smaller than 0,9 ml were eliminated by radioiodine, whereas this was the case of only 6/11 nodes exceeding this threshold. Conclusions Radioiodine given at radioablation removes 85,9 % (CI 75,4 - 92,4 %) of iodine-positive LNMs persisting after thyroidectomy in DTC, 94% of LNMs

The clinical significance of 18F-FDG-PET/CT in the follow-up of patients with differentiated thyroid carcinoma was evaluated and the results were compared with those of 18F-FDG-PET, 131I-whole-body scintigraphy including SPECT/CT (WBS) and ultrasound. In addition, it was the aim to investigate the impact of 18F-FDG-PET/CT on the therapeutic management. Patients, methods: 327 patients (209 women, 118 men; mean age 53 ± 18 years) with differentiated thyroid cancer (242 papillary, 75 follicular, 6 mixed, 1 Hurthle cell and 3 poorly differentiated tumours) were analyzed retrospectively at four tertiary referral centres. 289 18F-FDG-PET/CT and 118 18F-FDG-PET studies were performed in these patients between 2007 and 2010. In addition, an overall clinical evaluation was performed, including cytology, histology, thyroglobulin level, ultrasound, WBS, and subsequent clinical course in order to compare the molecular imaging results. Finally, the change in therapeutic management due to findings of 18F-FDG-PET/CT was investigated. Results: The sensitivity of 18F-FDG-PET/CT was 92%, the specificity was 95%. Sensitivity and specificity of 18F-FDG-PET alone were 67% and 93%, respectively. WBS showed a sensitivity of 65% and a specificity of 94%. The corresponding values of ultrasound were 37% and 94%, respectively. The sensitivity of 18F-FDG-PET/CT in the group of patients with a negative WBS (n=194) amounted to 96%. When 18F-FDG-PET/CT and WBS were considered in combination, tumour tissue was missed in only 2 out of 133 patients; when 18F-FDG-PET and WBS were combined, tumour tissue was missed in 1 out of 24 patients. 18F-FDG-PET/CT resulted in management change in 43% (n=57/133) with a decision on surgical approach in 20% (n=27/133). Conclusions: 18F-FDG-PET/CT is superior to 18F-FDG-PET alone in patients with differentiated thyroid cancer and has a direct impact on the therapeutic management of patients with suspected local recurrence or metastases, particularly in those with negative WBS.

Zielsetzung: Wie in vorausgehenden Arbeiten gezeigt (Ullrich et al.), beeinflussen Schwächungskorrekturfehler die Aktivitätsmessungen an pulmonalen Rundherden. Ziel war, den maximalen Messfehler zu simulieren und durch Schwächungskorrektur mit 4D-CT/Averaging-CT zu verringern.

Zielsetzung: Ex-vivo-Untersuchungen zum Einfluss der Atembewegung auf die Aktivitäts- und Volumenbestimmung pulmonaler Noduli im PET-CT.

The diagnosis of Alzheimer's dementia is currently changing from a late and exclusion diagnosis towards a pathophysiology-based early and positive diagnosis. Especially advances in neuro-chemical dementia diagnostics in the cerebrospinal fluid (NDD-CSF) and imaging techniques like PET, SPECT or MRI are of particular interest. Unfortunately, many studies investigated only either one or other technique. In the present study 56 patients (average 67.1 years: average mini-mental status test (MMST) 22.2) were examined with the clinical diagnosis of Alzheimer's dementia. All patients both underwent NDD-CSF as well as 99mTc-SPECT. Only the SPECT, but not the NDD-CSF correlated with disease severity. Sensitivity of NDD-CSF was 89% and SPECT 48% for all patients and 93% resp, 61% for patients with MMST <24. Below MMST 20 both methods had equal sensitivity. Both diagnostic techniques showed no statistic coherence (p=0.27), neither after correction for subgroups like disease severity or the APOE genotype. Our results are compatible with the hypothesis that the NDD-CSF reflects beta-amyloid-aggregation and Tau-Protein pathology as a pathophysiologic biomarker. Our results suggest that SPECT is rather a state parameter for the rCBF changes following cortical neurodegeneration.

We used functional magnetic resonance imaging to explore the brain mechanisms of changing point of view (PoV) in a visuospatial memory task in 3D space. Eye movements were monitored and BOLD signal changes were measured while subjects were presented with 3D images of a virtual environment. Subjects were required to encode the position of a lamp in the environment and, after changing the PoV (angular difference varied from 0 to 180 in 45 steps), to decide whether the lamp position had been changed too or not.Performance data and a scan-path analysis based on eye movement support the use of landmarks in the environment for coding lamp position and increasing spatial updating costs with increasing changes of PoV indicating allocentric coding strategies during all conditions (0 degrees- to 180 degrees-condition).Subtraction analysis using SPM revealed that a parieto-temporo-frontal network including left medial temporal areas was activated during this 3D visuospatial task, independent of angular difference. The activity of the left parahippocampal area and the left lingual gyrus (but not the hippocampus) correlated with increasing changes of the PoV between encoding and retrieval, emphasizing their specific role in spatial scene memory and allocentric coding. The results suggest that these areas are involved in a continuous matching process between internal representations of the environment and the external status quo. In addition, hippocampal activation correlated with performance was found indicating successful recall of spatial information. Finally, in a prefrontal area comprising, the so-called "deep" frontal eye field, activation was correlated with the amount of saccadic eye movements confirming its role in oculomotor processes. (c) 2007 Elsevier Inc. All rights reserved.

In this functional positron emission tomography study brain activations during an auditory lexical decision task with two experimental conditions were investigated. First, the subjects had to discriminate between real words and nonwords; second, real words varied with pseudowords. Comparing each of these tasks to an auditory control condition we found bilateral activation of the superior temporal and inferior frontal gyrus, lateralized to the left in the pseudoword condition. The comparison of the lexical decision tasks revealed higher rCBF during the pseudo-/real word decisions within BA 47, adjacent to Broca's area, and the anterior cingulate. The data support the notion that the lexical decision during a nonword task is mainly based on a phonological discrimination process, whereas a pseudoword task more strongly requires lexical access resulting in activation of BA 47.

Summary: Aim: In cognitive neuroscience regional cerebral blood flow (rCBF) imaging with positron-emission-tomography (PET) is a powerful tool to characterize different aspects of cognitive processes by using different data analysis approaches. By use of an n-back verbal working memory task (varied from 0- to 3-back) we present cognitive subtraction analysis as basic strategy as well as parametric and covariance analyses and discuss the results. Methods: Correlation analyses were performed using the individual performance rate as an external covariate, computing inter-regional correlations, and as network analysis applying structural equation modelling to evaluate the effective connectivity between the involved brain regions. Results: Subtraction analyses revealed a fronto-parietal neuronal network also including the anterior cingulate cortex and the cerebellum. With higher memory load the parametric analysis evidenced linear rCBF increases in prefrontal, pre-motor and inferior parietal areas including the precuneus as well as in the anterior cingulate cortex. The rCBF correlation with the individual performance as external covariate depicted negative correlations in bilateral prefrontal and inferior parietal regions, in the precuneus and the anterior cingulate cortex. The network analysis demonstrated mainly occipito-frontally directed interactions which were predominantly left-hemispheric. Additionally, strong linkages were found between extrastriate and parietal regions as well as within the parietal cortex. Conclusion: The data analysis approaches presented here contribute to an extended and more elaborated understanding of cognitive processes and their different sub-aspects.

This functional magnetic resonance imaging study investigates commonalties and differences in working memory (WM) processes employing different types of stimuli. We specifically sought to characterize topographic convergence and segregation with respect to prefrontal cortex involvement using verbal, spatial, real object and shape memory items in a two-back WM task. Both the dorsolateral and ventrolateral prefrontal cortices are conjointly activated across all stimulus types. No stimulus-specific differences in the activation patterns of the prefrontal cortex could be demonstrated giving support to the view of an amodal prefrontal involvement during WM processes. However, extra-frontal regions specialized on feature processing and involved in the preprocessing of the stimuli were selectively activated by these different subtypes of WM. These selectively activated regions are assigned to parts of the ventral and dorsal stream.

In this study, we aimed to characterize commonalities and differences of activation patterns during verbal episodic memory processes across different presentation modalities (visual or auditory) and different imagery content (low or high) of the presented verbal memory items. Twelve right-handed normal male volunteers took part in the study. Each subject underwent six O-15-butanol positron emission tomography scans. In six of the subjects the verbal material was presented visually, and in six subjects auditorily. The subjects had to encode and retrieve two sets of 12 word-pair associates of high (set 1) or low (set 2) imagery content (not semantically related). The presentation of nonsense words served as reference condition. Images were analyzed with statistical parametric mapping. Conjunction analysis was used to identify commonalities, and cognitive subtraction analysis was used to identify differences. The use of conjunction analyses enabled us to identify commonly activated regions involved in episodic encoding and retrieval of verbal material irrespective of the presentation modality or the imagery content. Our results add further evidence to recent findings that bilateral prefrontal activations are important for episodic retrieval and thus the role of the left prefrontal cortex has been underestimated during episodic retrieval. Furthermore, our results support the idea of functionally segregated areas in the prefrontal cortex. Finally, our results provide strong evidence that mesial parietal cortex (precuneus) involvement is not restricted to processes involving imagery.

3-[123I]Iodo-α-methyl-L-tyrosine (IMT) is employed clinically as a tracer of amino acid transport in brain tumours using single-photon emission tomography (SPET). This study investigates the role of IMT SPET in the non-invasive histological grading and prognostic evaluation of cerebral gliomas. The files of patients investigated by IMT SPET in our clinic between 1988 and 1996 were evaluated retrospectively. Complete follow-up was available for 58 patients with cerebral gliomas investigated by IMT SPET shortly after tumour diagnosis. Seventeen patients had low-grade gliomas (WHO grade II), 14 had anaplastic gliomas (WHO grade III) and 27 had glioblastomas (WHO grade IV). Thirty-six cases were primary tumours and 22 cases, recurrences. Maximal and mean tumour-to-brain (T/B) ratios of IMT uptake at the first IMT SPET investigation were related to histological grading and survival time. Patients with low-grade gliomas showed significantly longer survival than patients with high-grade (grade III or IV) tumours. Gliomas without contrast enhancement on computed tomography or magnetic resonance imaging scans were associated with longer patient survival than tumours with contrast enhancement. The T/B ratios of IMT SPET showed no differences in relation to histological grading [WHO grade II: 1.73±0.59; WHO grade III: 1.74±0.38; WHO grade IV: 1.59±0.35, (mean±SD, T/B ratios of mean tumour uptake)]. The median survival time of patients with a high T/B ratio on IMT SPET was not significantly different from that of patients with a low T/B ratio (T/B ratio <1.6, 14.8 months; T/B ratio ≥1.6, 13.0 months). Thus, no evidence could be found for a relationship between IMT uptake in cerebral gliomas and either histological grading or survival time. Nevertheless, IMT SPET constitutes a useful method for the detection of primary and recurrent gliomas, determination of tumour extent and individual follow-up.