Intraplaque angiogenesis is associated with the occurrence of atherosclerotic plaque rupture. Cardiovascular molecular imaging can be used for the detection of rupture-prone plaques. Imaging with ...radiolabeled bevacizumab, a monoclonal anti-vascular endothelial growth factor (VEGF)-A, can depict VEGF levels corresponding to the angiogenic status in tumors. We determined the feasibility of 89Zr-bevacizumab imaging for the detection of VEGF in carotid endarterectomy (CEA) specimens. Five CEA specimens were coincubated with 89Zr-bevacizumab and aspecific 111In-labeled IgG to determine the specificity of bevacizumab accumulation. In 11 CEA specimens, 89Zr-bevacizumab micro-positron emission tomography (PET) was performed following 2 hours of incubation. Specimens were cut in 4 mm wide segments and were stained for VEGF and CD68. In each segment, the mean percent incubation dose per gram of tissue (%Inc/g) and tissue to background ratio were determined. A 10-fold higher accumulation of 89Zr-bevacizumab compared to 111In-IgG uptake was demonstrated by gamma counting. The mean %Inc/ghot spot was 2.2 ± 0.9 with a hot spot to background ratio of 3.6 ± 0.8. There was a significant correlation between the segmental tissue to background uptake ratio and the VEGF score (ρ = .74, p < .001). It is feasible to detect VEGF tissue concentration within CEA specimens using 89Zr-bevacizumab PET. 89Zr-bevacizumab accumulation in plaques is specific and correlates with immunohistochemistry scores.
Fluorodeoxyglucose positron emission tomography scanning has an established role in the diagnostic work-up of many malignant diseases and also in the evaluation of cancer treatment response. ...Fluorodeoxyglucose positron emission tomography may, however be non-specific as infectious processes are depicted as well.
We present a patient with longstanding leg pain and weakness due to plexopathy developed a few years after treatment for prostate cancer. Prostate-specific antigen was raised and magnetic resonance imaging showed contrast uptake in thickened sacral nerves, suspicious for metastasis. While fluorodeoxyglucose positron emission tomography showed increased uptake in the plexus region, (11)C-Choline- positron emission tomography did not show any uptake. It was concluded that the FDG uptake reflected plexus neuritis and no tumor. Treatment for pain relief was started.
(11)C-Choline- positron emission tomography can be used to detect metastasis in patients with plexopathy suspicious for malignancy, while fluorodeoxyglucose positron emission tomography is more sensitive to inflammatory processes.
FDG-PET, combined with CT, is nowadays getting more and more relevant for the diagnosis of several infectious and inflammatory diseases and particularly for therapy monitoring. Thus, this paper gives ...special attention to the role of FDG-PET/CT in the diagnosis and therapy monitoring of infectious and inflammatory diseases. Enough evidence in the literature already exists about the usefulness of FDG-PET/CT in the diagnosis, management, and followup of patients with sarcoidosis, spondylodiscitis, and vasculitis. For other diseases, such as inflammatory bowel diseases, rheumatoid arthritis, autoimmune pancreatitis, and fungal infections, hard evidence is lacking, but studies also point out that FDG-PET/CT could be useful. It is of invaluable importance to have large prospective multicenter studies in this field to provide clear answers, not only for the status of nuclear medicine in general but also to reduce high costs of treatment.
Histological proof remains the gold standard for the diagnosis of amyloidosis. Nuclear medicine imaging techniques are able to determine the amyloid load in the body. Currently, the best imaging ...modality is (123)I-SAP scintigraphy. This modality has high sensitivity for detecting amyloid deposits in all amyloid subtypes. Involvement of liver and spleen can be visualized before clinical signs are present. The addition of single photon emission computed tomography improves the differentiation of overlying organs. However, (123)I-SAP is not FDA approved. Its availability is limited to two centres in Europe. Furthermore, it is not suitable for imaging cardiac involvement of amyloidosis, due to movement, blood-pool content and lack of fenestrated endothelial in the myocardium. Phosphate derivates labelled with (99m)Tc, are able to detect calcium compounds in cardiac amyloidosis. Finally, (123)I-MIBG, an analogue of norepinephrine, can detect cardiac sympathetic innervation abnormalities as a consequence of amyloid deposits. Both these last techniques seem to be able to detect cardiac involvement before echocardiographic parameters are present. We illustrate the clinical use of these modalities with two patients with ATTR type amyloidosis.
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