<p>PDF file - 16KB, Region-based sensitivities and specificities (and 95% confidence intervals) of DWI-MRI in patients with DLBCL, follicular lymphoma, and Hodgkin lymphoma.</p>
<p>Invasive ductal carcinoma G3 in a 67-year-old woman, retroareolar in the right breast [continued from Figure S1]. (A) On 3D 1H-MRSI, the lesion demonstrates elevated Cho levels (SNR 10.23). (B) On 18FDG-PET, the lesion is highly 18FDG-avid, with a maximum SUV of 51.9. (C) This tumor was true-positive according to all techniques, allowing an accurate classification as malignant with MP 18FDG-PET-MRI.</p>
Poster: ECR 2015 / C-1135 / Diagnostic value of PET/MR and DWI for the evaluation of malignant lymphoma: preliminary results on 17 patients. by: C. Giraudo , M. Weber, M. Raderer, G. Karanikas, M. Mayerhofer; Vienna/AT
Poster: ECR 2014 / C-1017 / Is there a correlation of quantitative MRI breast density measurement at 3T and SUVmax in 18FDG? by: J. Wengert, T. H. Helbich, P. A. T. Baltzer, M. Bernathova, P. Kapetas, H. Magometschnigg, W. Bogner, G. Karanikas, K. Pinker-Domenig; Vienna/AT
Nuclear medicine plays an important role in the imaging of neuroendocrine tumors (NETs). Somatostatin receptor scintigraphy (SRS) with (111)In-labeled somatostatin receptor analogs is a standard procedure for the detection and staging of NET. Based on the ability of NETs to store biogenic amines, this study evaluated whether 6-(18)F-fluoro-L-DOPA ((18)F-FDOPA) is a suitable PET tracer for NETs.Twenty-three patients with histologically verified NETs in advanced stages were consecutively enrolled in the study. All patients underwent PET with (18)F-FDOPA, CT, and SRS within 6 wk. In patients with discrepancies between nuclear medicine and radiologic methods, follow-up investigations were performed by CT, MRI, and ultrasound. (18)F-FDOPA PET with attenuation correction was done 30 and 90 min after injection from the neck to the upper legs. SRS was performed with (111)In-DOTA-D-Phe(1)-Tyr(3)-octreotide at 6 and 24 h. All images were read without knowledge of the results of the other modalities. In every patient, the following regions were evaluated separately: bones, mediastinum, lungs, liver, pancreas, and others, including the abdominal and supraclavicular lymph nodes, spleen, and soft- tissue lesions. The findings were confirmed by clinical examination. The nuclear medicine methods were compared against morphologic imaging, which was considered as gold standard.The most frequently involved organs or regions were the liver (prevalence, 70%) and bone (52%), followed by mediastinal foci (31%), the lungs (22%), and the pancreas (13%). Fifty-two percent of patients had various lymphatic lesions. (18)F-FDOPA was most accurate in detecting skeletal lesions (sensitivity, 100%; specificity, 91%) but was insufficient in the lung (sensitivity, 20%; specificity, 94%); SRS yielded its best results in the liver (sensitivity, 75%; specificity, 100%); however, it was less accurate than PET in all organs. In about 40%, initial CT failed to detect bone metastases shown by PET that were later on verified by radiologic follow-up.(18)F-FDOPA PET performs better than SRS in visualizing NETs and may even do better than CT for bone lesions. SRS is essential to establish the usefulness of therapy with somatostatin analogs, yet is less accurate than (18)F-FDOPA PET for staging.
Reflecting one's mental self is a fundamental process for evaluating the personal relevance of life events and for moral decision making and future envisioning. Although the corresponding network has been receiving growing attention, the driving neurochemical mechanisms of the default mode network (DMN) remain unknown. Here we combined positron emission tomography and functional magnetic resonance imaging to investigate modulations of the DMN via serotonin-1A receptors (5-HT 1A ), separated for 5-HT autoinhibition (dorsal raphe nucleus) and local inhibition (heteroreceptors in projection areas). Using two independent approaches, regional 5-HT 1A binding consistently predicted DMN activity in the retrosplenial cortex for resting-state functional magnetic resonance imaging and the Tower of London task. On the other hand, both local and autoinhibitory 5-HT 1A binding inversely modulated the posterior cingulate cortex, the strongest hub in the resting human brain. In the frontal part of the DMN, a negative association was found between the dorsal medial prefrontal cortex and local 5-HT 1A inhibition. Our results indicate a modulation of key areas involved in self-referential processing by serotonergic neurotransmission, whereas variations in 5-HT 1A binding explained a considerable amount of the individual variability in the DMN. Moreover, the brain regions associated with distinct introspective functions seem to be specifically regulated by the different 5-HT 1A binding sites. Together with previously reported modulations of dopamine and GABA, this regional specialization suggests complex interactions of several neurotransmitters driving the default mode network.
High levels of fatty acid synthase have shown to correlate with the aggressiveness of prostate cancer. As [(11) C]acetate exhibits a close correlation with the level of fatty acid synthase, we aimed to assess whether the SUV in [(11) C]acetate PET serves as a suitable prognostic marker in patients with recurrent prostate cancer.In 123 consecutive patients, examined between 2010 and 2014, the maximum standardized uptake value (SUVmax) of local recurrences as well as lymph node and bone metastases was measured. Choosing the spleen as a standard for relatively high physiological uptake, a ratio of tumor to spleen uptake (SUVts) was calculated for standardizing the uptake, too. The corresponding initial Gleason scores (GS) and serum-PSA levels around the time of the performed PET/CT for each patient were retrospectively collected and PSA doubling together with PSA velocity were determined. For further analysis patients were divided with regard to their initial Gleason score (≤3 + 4 and ≥ 4 + 3). The median of PSA velocity was calculated to separate patients with a high and low PSA velocity and Mann-Whitney U or Student's t-test were used, testing for significant differences. For correlation Spearmen-Rho test was used.PET was positive for recurrence in 82/123 patients. PSA was significantly higher in PET-positive than in negative patients (5.9 vs. 3.2 ng/ml; P = 0.006). Initial Gleason score did not differ in PET negative and positive patients (P = 0.3), whereas PSA velocity was markedly higher in PET positive patients (0.4 vs. 0.1 ng/ml/month; P = 0.01). Median SUVmax of PET positive patients was 5.23 (mean 5.78; range 0.9-16.8) and meadian SUVts was 0.78 (mean 0.84, range 0.14-2.50). SUVts was significantly higher in patients with high PSA velocity (SUVts 0.76 vs. 0.92; P = 0.009), whereas SUVmax failed statistical significance (5.4 vs. 6.3 ng/ml/month; P = 0.08). Patients with a high SUVmax proved to have a significantly higher median Gleason score compared to low uptake 8.0 vs. 7.0; P = 0.004). Vice versa both SUVmax (GS 6: 5.0; GS 7: 5.6; GS 8: 5.7; GS 9: 6.5; r = 0.30, P = 0.008) and SUVts (GS 6: 0.63; GS 7: 0.68; GS 8: 0.85; GS 9: 0.89; r = 0.30, P = 0.006) significantly correlated with Gleason score. Patients with a Gleason score ≤ 3 + 4 had a significantly lower SUVmax (4.8 vs. 5.7; P = 0.02) and SUVts (0.67 vs. 0.85; P = 0.02) as compared to a Gleason score ≥ 4 + 3.[(11) C]acetate uptake demonstrated to correlate with initial Gleason score. Furthermore, patients with a high PSA velocity proved to have higher [(11) C]acetate uptake in tumor lesions.
Patienten und Methoden: Bei dieser Arbeit handelt es sich um eine retrospektive Studie über 60 Patienten, die wegen eines PSA-Rezidivs eine 11C-Acetat-PET/CT-Untersuchung erhielten. Dreiundvierzig Patienten wurden chirurgisch behandelt und 17 Patienten wurden unter kurativer Zielsetzung bestrahlt. Die PET/CT-Bilder wurden von zwei erfahrenen Spezialisten befundet und hinsichtlich eines Rezidivs als positiv oder negativ klassifiziert. Die PET/CT-Ergebnisse wurden mit Biopsien, anderen bildgebenden Verfahren oder mit klinischem Follow-up korreliert. Die Detektionsrate sowie die Lokalisation der Rezidive wurden untersucht.
Background/Aim: Positron emission tomography/computed tomography (PET/CT) plays an important role in cancer localization in ectopic Cushing's syndrome (ECS). However, the choice of the optimal tracer for investigation of this disease is still unclear. We aimed to evaluate the diagnostic feasibility of [18F]fluoro-2-deoxyglucose ([18F]FDG), [18F]fluoro-L-dihydroxyphenylalanine ([18F] FDOPA), and [68Ga]-DOTA-1-Nal3-octreotide ([68Ga]-DOTANOC) in ECS. Patients and Methods: All PET/CT scans of patients admitted to our department for suspected ECS between 2010 and 2020 were retrospectively analysed. Results: Collectively, 30 PET/CT examinations, 11 with [18F]FDOPA, 11 with [18F]FDG and 8 with [68Ga]GaDOTANOC were conducted for 18 patients eligible for analysis. [18F]FDG detected the tumour in 3/6 of the cases, [18F]FDOPA in 3/4, and [68Ga]GaDOTANOC in 3/3. [18F]FDOPA was the only tracer without false positive results. Conclusion: [68Ga]GaDOTANOC and [18F]FDOPA showed superior results compared to [18F]FDG, although the sensitivity of the tracers might be influenced by the aetiology of the tumour underlying the ECS.
