Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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We examined whether measurement of the adenosine A(1) receptor (A1-R) with PET can predict the severity of ischemic brain damage using an occlusion and reperfusion model of the cat middle cerebral artery (MCA) and [1-methyl-(11)C]8-dicyclopropylmethyl-1-methyl-3-propylxanthine (MPDX), a positron-emitting radioligand developed at our institution. ⋯ The degree of decreased MPDX binding to A1-Rs after reperfusion was a sensitive predictor of severe ischemic insult. MPDX PET has good potential to become a suitable in vivo imaging technique for evaluating the function of adenosine and A1-Rs in relation to cerebral ischemia.
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The routine use of PET/CT fusion imaging in a large oncology practice has led to the realization that (18)F-FDG uptake into normal fat and muscle can be a common source of potentially misleading false-positive PET imaging in the neck, thorax, and abdomen. The goal of this study was to characterize this normal variant of (18)F-FDG uptake in terms of incidence and characteristic extent. ⋯ Increased (18)F-FDG uptake is sometimes seen in individual muscles and in adipose tissue in the neck and shoulder region, axillae, mediastinum, and perinephric regions. There is also associated (18)F-FDG uptake in the intercostal spaces in the paravertebral regions. (18)F-FDG uptake in neck fat is more commonly seen in female patients and the pediatric population. The pattern of uptake as well as the age and sex distribution suggest that the (18)F-FDG in fat is in the brown adipose tissue. It is important to recognize this uptake pattern to avoid false interpretation of this benign normal variant as a malignant finding on (18)F-FDG PET scans.
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The epidermal growth factor receptor (EGFR) is an attractive target for the design of radiotherapeutic agents for breast cancer because it is present on almost all estrogen receptor-negative, hormone-resistant tumors with a poor prognosis. In this study, we describe the antitumor effects and normal tissue toxicity of the novel Auger electron-emitting radiopharmaceutical (111)In-labeled diethylenetriaminepentaacetic acid-human epidermal growth factor ((111)In-DTPA-hEGF) administered to athymic mice bearing EGFR-positive human breast cancer xenografts. ⋯ (111)In-DTPA-hEGF exhibited strong antitumor effects against MDA-MB-468 breast cancer xenografts overexpressing EGFR. The highest tumor localization, radiation-absorbed doses, and growth inhibition were achieved for small, nonestablished tumors, suggesting that the radiopharmaceutical may be most valuable for the treatment of small-volume metastatic breast cancer or occult micrometastases in an adjuvant setting.
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Comparative Study
Prognostic value of PET using 18F-FDG in Hodgkin's disease for posttreatment evaluation.
Detection of relapse after completion of therapy in patients with Hodgkin's disease (HD) and non-Hodgkin's lymphomas (NHL) constitutes an important challenge in modern medical imaging. An accurate assessment of the presence of residual disease is essential to determine which patients would benefit from additional therapy. The objective of this study was to assess the diagnostic accuracy of (18)F-FDG PET in detecting residual disease or relapse during the posttherapy period in patients with HD in comparison with CT. We also established different predictive values for (18)F-FDG PET according to the time interval between the end of therapy and the PET study. ⋯ Positive (18)F-FDG PET after the end of therapy in HD patients is a strong predictor of relapse. A negative PET study is also an excellent predictor of good prognosis. The diagnostic accuracy of (18)F-FDG PET to assess the presence of residual disease after therapy is superior to that of CT.
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Comparative Study
Nonvisualization of axillary sentinel node during lymphoscintigraphy: is there a pathologic significance in breast cancer?
The aim of this study was to define the factors associated with nonvisualization of a sentinel node (SN) in the axilla area during preoperative lymphoscintigraphy. ⋯ Patients with unsuccessful axillary mapping have an increased risk for axillary involvement.