Hell J Nucl Med
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Medullary carcinoma of the thyroid (MTC) is a rare neuroendocrine tumour (NET) that expresses somatostatin receptors on the cell membrane and secretes calcitonin. Surgery is the primary curative modality but is achieved only when the diagnosis is timely so there is a high rate of persistent and recurrent disease indicated by a rise in the serum calcitonin levels. Successful management of recurrent disease requires accurate localisation with cross sectional and functional imaging. The introduction of gallium-68-Dotatate ((68)Ga-Dotatate) peptides positron emission tomography/computerized tomography (PET/CT) has significantly improved the detection of NET and has been reported as a valuable adjunct in MTC localisation. We retrospectively reviewed our cases of MTC to correlate the detectability of (68)Ga-Dotatate in relation to calcitonin levels and assess suitability of inoperable patients for peptide receptor radionuclide therapy (PRRT). ⋯ (68)Ga-Dotatate PET/CT is an effective tool for localising metastatic spread of MTC. It appears to be most effective in the presence of higher levels of serum calcitonin, probably in excess of 500pg/mL. The results of our small cohort had an impact on staging and management with the introduction of peptide receptor radionuclide therapy for inoperable disease.
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Editorial Case Reports
Is it practical and cost effective to detect differentiated thyroid carcinoma metastases by (18)F-FDG PET/CT, by (18)F-FDG SPET/CT or by (131)I SPET/CT?
Fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose positron emission tomography/computerized tomography ((18)F-FDG PET/CT) plays an important role in detecting differentiated thyroid carcinoma (DTC) metastases with elevated thyroglobulin (Tg) and negative radioiodine ((131)I) uptake. In conclusion, (18)F-FDG PET/CT may fail to detect all DTC metastases, while (131)I WBS combined with (131)I SPET/CT may be a better cheaper and diagnostic tool as suggested by the case we presented here. Positive metastases in both (131)I and (18)F-FDG SPET/CT may indicate worse prognosis. Future research may add more evidence as to which is the best diagnostic imaging modality and relate it to the molecular mechanism of the uptake of the radionuclide used.
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To quantify fluorine-18 fluorodeoxyglucose ((18)F-FDG) uptake in the aorta and peripheral arteries and assess the variation of (18)F-FDG uptake with age and cardiovascular risk factors. ⋯ An increase in (18)F-FDG uptake was observed in the peripheral arteries and aorta with increasing age. Cardiovascular risk factors were significantly correlated with (18)F-FDG uptake in aorta. The early detection of atherosclerosis with (18)F-FDG PET may allow for the initiation of preventative interventions prior to the manifestation of significant structural abnormalities or symptoms of disease.
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Letter Case Reports
Multifocal septic osteomyelitis mimicking skeletal metastatic disease in a patient with prostate cancer.
We present an unusual case of a 59 years old patient with prostate cancer, who was referred to our hospital with pleurodenia, low back and other sites of bone ostalgia, for bone scintiscan. The patient underwent a whole body bone scanning after the intravenous administration of 740MBq (99m)Tc-methylene diphosphonate (MDP). The main findings of the study were: increased radiotracer uptake at the T5, T9-T10 vertebrae, the head of the 11th rib and the area of the left sternoclavicular joint (SCJ), which were initially attributed to skeletal metastatic lesions. ⋯ Four months later the patient had fully recovered and his blood tests were normal. The patient had not been referred to an oncology department yet, as the onset of the arthritis occurred about two weeks after the diagnosis of prostate cancer. In conclusion, we present a patient with known malignancy, fever, skeletal pain and multiple bone lesions in the (99m)Tc-MDP and the MRI examination, not due to metastatic disease but to septic arthritis.
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Brown tumor is one of the skeletal manifestations of hyperparathyroidism. It is a benign but locally aggressive bone lesion and its differential diagnosis with giant cell containing skeletal tumors or metastases may be complicated. We present a male patient with chronic renal failure who was initially misdiagnosed as having a giant-cell rich neoplasm of bone in his right thumb. ⋯ Parathyroid hyperplasia was finally diagnosed with (99m)Tc-methoxyisobutylisonitrile (MIBI) parathyroid scintigraphy. Fluorine-18-FDG avid lytic lesions were attributed to hyerparathyroidism associated brown tumors instead of multiple metastases. In conclusion, we present a patient with chronic renal insufficiency, who suffered from secondary and later from tertiary HPT with polyostotic brown tumors, which were best shown by the (18)F-FDG PET/CT than by the (99m)Tc-MDP or the (99m)Tc-MIBI scans.