Refine
Has Fulltext
- yes (14)
Is part of the Bibliography
- yes (14)
Document Type
- Journal article (14) (remove)
Language
- English (14)
Keywords
- multiple myeloma (6)
- PET (3)
- medicine (3)
- molecular imaging (3)
- positron emission tomography (3)
- 18F-FDG PET/CT (2)
- CXCR4 (2)
- FDG (2)
- radionuclide therapy (2)
- theranostics (2)
- 11C-Methionine PET/CT (1)
- 18FDG-PET/CT (1)
- 68Ga-DOTATATE (1)
- 68Ga-Pentixafor PET/CT (1)
- Atherosclerotic plaque (1)
- Cardiovascular risk factors (1)
- FDG-PET/CT (1)
- IBA-1 (1)
- Macrophage (1)
- Medizin (1)
- Multiple myeloma (1)
- PET/CT (1)
- PRRT (1)
- Parkinson’s disease (1)
- Somatostatin receptor (1)
- TBI (1)
- TSPO (1)
- \(^{11}\)C-Methionine-PET (1)
- \(^{11}\)C-methionine (1)
- \(^{18}\)F-FDG PET/CT (1)
- autoradiography (1)
- bone disease (1)
- cancer treatment (1)
- cholinergic activity (1)
- diffuse (1)
- esophagogastric junction (1)
- experience (1)
- focal (1)
- glioblastoma multiforme (1)
- glioma (1)
- health care (1)
- imaging techniques (1)
- immunohistochemistry (1)
- immunostaining (1)
- isotopes (1)
- levodopa-induced dyskinesia (1)
- macrophages (1)
- magnetic resonance imaging (1)
- management (1)
- metabolic tumor volume (MTV) (1)
- methionine (1)
- microglial cells (1)
- neuroinflammation (1)
- pattern (1)
- peptide receptor (1)
- photons (1)
- progression (1)
- radiogenomics (1)
- relapse (1)
- sarcoidosis (1)
- signal to noise ratio (1)
- smoldering myeloma (1)
- somatostatin (1)
- somatostatin receptors (1)
- stem-cell transplantation (1)
- super ultraviolet (1)
- thyroid carcinomas (1)
- total lesion glycolysis (TLG) (1)
- total lesion methionine uptake (TLMU) (1)
- treatment response (1)
- weight drop (1)
Institute
- Klinik und Poliklinik für Nuklearmedizin (12)
- Medizinische Klinik und Poliklinik II (7)
- Abteilung für Molekulare Innere Medizin (in der Medizinischen Klinik und Poliklinik II) (2)
- Institut für diagnostische und interventionelle Radiologie (Institut für Röntgendiagnostik) (2)
- Neurologische Klinik und Poliklinik (2)
- Institut für Klinische Epidemiologie und Biometrie (1)
- Institut für Klinische Transfusionsmedizin und Hämotherapie (1)
- Institut für Medizinische Strahlenkunde und Zellforschung (1)
- Institut für diagnostische und interventionelle Neuroradiologie (ehem. Abteilung für Neuroradiologie) (1)
- Klinik und Poliklinik für Strahlentherapie (1)
Sonstige beteiligte Institutionen
EU-Project number / Contract (GA) number
- 680966 (1)
Background
Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. Tumor-associated macrophages (TAM) have been shown to promote malignant growth and to correlate with poor prognosis. [1,4,7,10-tetraazacyclododecane-NN′,N″,N′″-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE) labeled with Gallium-68 selectively binds to somatostatin receptor 2A (SSTR2A) which is specifically expressed and up-regulated in activated macrophages. On the other hand, the role of SSTR2A expression on the cell surface of glioma cells has not been fully elucidated yet. The aim of this study was to non-invasively assess SSTR2A expression of both glioma cells as well as macrophages in GBM.
Methods
15 samples of patient-derived GBM were stained immunohistochemically for macrophage infiltration (CD68), proliferative activity (Ki67) as well as expression of SSTR2A. Anti-CD45 staining was performed to distinguish between resident microglia and tumor-infiltrating macrophages. In a subcohort, positron emission tomography (PET) imaging using \(^{68}Ga-DOTATATE\) was performed and the semiquantitatively evaluated tracer uptake was compared to the results of immunohistochemistry.
Results
The amount of microglia/macrophages ranged from <10% to >50% in the tumor samples with the vast majority being resident microglial cells. A strong SSTR2A immunostaining was observed in endothelial cells of proliferating vessels, in neurons and neuropile. Only faint immunostaining was identified on isolated microglial and tumor cells. Somatostatin receptor imaging revealed areas of increased tracer accumulation in every patient. However, retention of the tracer did not correlate with immunohistochemical staining patterns.
Conclusion
SSTR2A seems not to be overexpressed in GBM samples tested, neither on the cell surface of resident microglia or infiltrating macrophages, nor on the surface of tumor cells. These data suggest that somatostatin receptor directed imaging and treatment strategies are less promising in GBM.
The aim of this study was to investigate the prognostic value of 18F-fluoro-deoxyglucose positron emission tomography–computed tomography (18F-FDG-PET/CT) in 37 patients with a history of multiple myeloma (MM) and suspected or confirmed recurrence after stem cell transplantation (SCT). All patients had been heavily pre-treated. Time to progression (TTP) and overall survival (OS) were correlated to a number of different PET-derived as well as clinical parameters. Impact on patient management was assessed.
Absence of FDG-avid MM foci was a positive prognostic factor for both TTP and OS (p<0.01). Presence of >10 focal lesions correlated with both TTP (p<0.01) and OS (p<0.05). Interestingly, presence of >10 lesions in the appendicular skeleton proved to have the strongest association with disease progression. Intensity of glucose uptake and presence of extramedullary disease were associated with shorter TTP (p=0.037 and p=0.049, respectively). Manifestations in soft tissue structures turned out to be a strong negative predictor for both, TTP and OS (p<0.01, respectively). PET resulted in a change of management in 30% of patients.
Our data underline the prognostic value of 18F-FDG-PET/CT in MM patients also in the setting of post-SCT relapse. PET/CT has a significant impact on patient management.
Objectives
The aim of this study is to evaluate the quality of I-124 PET images with and without prompt gamma compensation (PGC) by comparing the recovery coefficients (RC), the signal to noise ratios (SNR) and the contrast to F-18 and Ga-68. Furthermore, the influence of the PGC on the quantification and image quality is evaluated.
Methods
For measuring the image quality the NEMA NU2-2001 PET/SPECT-Phantom was used containing 6 spheres with a diameter between 10 mm and 37 mm placed in water with different levels of background activity. Each sphere was filled with the same activity concentration measured by an independently cross-calibrated dose calibrator. The “hot” sources were acquired with a full 3D PET/CT (Biograph mCT®, Siemens Medical USA). Acquisition times were 2 min for F-18 and Ga-68, and 10 min for I-124. For reconstruction an OSEM algorithm was applied. For I-124 the images were reconstructed with and without PGC. For the calculation of the RCs the activity concentrations in each sphere were determined; in addition, the influence of the background correction was studied.
Results
The RCs of Ga-68 are the smallest (79%). I-124 reaches similar RCs (87% with PGC, 84% without PGC) as F-18 (84%). showing that the quantification of I-124 images is similar to F-18 and slightly better than Ga-68. With background activity the contrast of the I-124 PGC images is similar to Ga-68 and F-18 scans. There was lower background activity in the I-124 images without PGC, which probably originates from an overcorrection of the scatter contribution. Consequently, the contrast without PGC was much higher than with PGC. As a consequence PGC should be used for I-124.
Conclusions
For I-124 there is only a slight influence on the quantification depending on the use of the PGC. However, there are considerable differences with respect to I-124 image quality.
Background: Ga-[1,4,7,10-tetraazacyclododecane-N,N0,N00,N000-tetraacetic acid]-d-Phe1,Tyr3-octreotate (DOTATATE) positron emission tomography (PET) is commonly used for the visualization of somatostatin receptor (SSTR)-positive neuroendocrine tumors. SSTR is also known to be expressed on macrophages, which play a major role in inflammatory processes in the walls of coronary arteries and large vessels. Therefore, imaging SSTR expression has the potential to visualize vulnerable plaques. We assessed 68Ga-DOTATATE accumulation in large vessels in comparison to 18F-2-fluorodeoxyglucose (FDG) uptake, calcified plaques (CPs), and cardiovascular risk factors. Methods: Sixteen consecutive patients with neuroendocrine tumors or thyroid cancer underwent both 68Ga-DOTATATE and 18F-FDG PET/CT for staging or restaging purposes. Detailed clinical data, including common cardiovascular risk factors, were recorded. For a separate assessment, they were divided into a high-risk and a low-risk group. In each patient, we calculated the maximum target-to-background ratio (TBR) of eight arterial segments. The correlation of the TBRmean of both tracers with risk factors including plaque burden was assessed. Results: The mean TBR of 68Ga-DOTATATE in all large arteries correlated significantly with the presence of CPs (r = 0.52; p < 0.05), hypertension (r = 0.60; p < 0.05), age (r = 0.56; p < 0.05), and uptake of 18F-FDG (r = 0.64; p < 0.01). There was one significant correlation between 18F-FDG uptake and hypertension (0.58; p < 0.05). Out of the 37 sites with the highest focal 68Ga-DOTATATE uptake, 16 (43.2%) also had focal 18F-FDG uptake. Of 39 sites with the highest 18F-FDG uptake, only 11 (28.2%) had a colocalized 68Ga-DOTATATE accumulation. Conclusions: In this series of cancer patients, we found a stronger association of increased 68Ga-DOTATATE uptake with known risk factors of cardiovascular disease as compared to 18F-FDG, suggesting a potential role for plaque imaging in large arteries. Strikingly, we found that focal uptake of 68Ga-DOTATATE and 18F-FDG does not colocalize in a significant number of lesions.