Nuclear medicine communications
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The management of the patients with carcinoma of an unknown primary represents a difficult challenge in oncology. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) has provided new insights in the diagnosis, staging, and follow-up of oncological patients. ⋯ Whole-body FDG PET/CT has to be considered a useful method, especially in an early phase of the diagnostic workup of patients with carcinoma of an unknown primary syndrome, to optimize the management.
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Attenuation correction of PET data requires accurate determination of the attenuation map (mumap), which represents the spatial distribution of linear attenuation coefficients of different tissues at 511 keV. The presence of high-density metallic dental filling material in head and neck X-ray computed tomography (CT) scanning is known to generate streak artefacts in the resulting CT images and thus in the corresponding mumaps generated using CT-based attenuation correction. Consequently, an under/overestimation of activity concentration occurs in corresponding regions of the corrected PET images. The purpose of this study is to develop a simple yet practical approach for reduction of metallic dental implant artefacts in the generated mumaps. ⋯ The proposed MAR method provides a simple and convenient approach allowing correction for the presence of metal artefacts caused by dental implants without the need to manipulate the complex raw CT data. Further evaluation using a larger clinical PET/CT database is under way to evaluate the potential of the technique in a clinical setting.
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Meta Analysis
Thyroxine alone or thyroxine plus triiodothyronine replacement therapy for hypothyroidism.
Standard therapy for patients with hypothyroidism is replacement with synthetic thyroxine (T4). However, thyroxine plus triiodothyronine (T3) replacement therapy resulted in marked improvements in several items of the Profile of Mood States and in a few indices of psychometric function and quality of life. The adequacy of thyroxine alone versus thyroxine plus triiodothyronine to treat hypothyroidism has yielded conflicting results. ⋯ In conclusion, on the basis of data from recent studies, we conclude that combined T4 and T3 treatment does not improve well-being, cognitive function, or quality of life compared with T4 alone. T4 alone may be beneficial in improving psychological or physical well-being. According to the current evidence, T4 alone replacement may remain the drug of choice for hypothyroid patients.
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Meta Analysis
Value of 18F-FDG-PET/PET-CT in differentiated thyroid carcinoma with radioiodine-negative whole-body scan: a meta-analysis.
The aim of this study was to evaluate the diagnostic accuracy of 18F-fluorodeoxyglucose-PET (FDG-PET) and FDG-PET/computed tomography (CT) in the detection of recurrent or metastatic differentiated thyroid carcinoma (DTC) that was not identified by radioiodine whole-body scintigraphy (WBS). ⋯ FDG-PET is especially effective in detecting patients with elevated thyroglobulin levels and normal radioiodine WBS; FDG-PET/CT is a more sensitive method in the follow-up of thyroid cancer recurrence or metastases, particularly in those with negative WBS.