Usefulness of the FDG PET/CT in the management of cystic echinococcosis: A pilot study.

OBJECTIVES: Cystic echinococcosis is a zoonotic disease caused by the cestode Echinococcus granulosus. The activity of the cysts is assessed through the WHO-IWGE standardized classification based on ultrasound features. However, viability of the cysts is not always concordant with the activity assessed by ultrasound. The aim of the present study is to describe the metabolic activity of cysts in patients with cystic echinococcosis through FDG-PET. METHODS: Prospective observational study where adult patients diagnosed of cystic echinococcosis were offered to undergo FDG PET/CT before treatment onset. Demographic, clinical, radiological, and histopathological information was collected from all patients. RESULTS: Sixteen patients were included, 50% were male, and age ranged from 18 to 85 years. Most of the patients had liver involvement, and all patients had CE3, CE4 or CE5 stage of the WHO-IWGE classification. Only one patient (CE5) had an increased 18F-FDG uptake of the cyst in the FDG PET/CT. From the 5 patients who underwent surgical treatment, only one showed signs of viability of the cyst: a patient with CE5 with no increased 18F-FDG uptake of the cyst. CONCLUSION: In our pilot study, we did not find the correlation between the FDG PET/CT imaging and the cystic echinococcosis cyst bioactivity.

[Diagnosis and follow-up of head and neck paragangliomas. Contributions of nuclear medicine]. / Diagnóstico y control evolutivo de los paragangliomas de cabeza y cuello. Aportaciones de la medicina nuclear.

Head and neck paragangliomas are neuroendocrine tumors that express somatostatin type 2 receptors and can consequently be visualized through nuclear imaging techniques, using radionuclide-labelled somatostatin analogs, specifically 111In-pentetreotide. 111In-pentetreotide scintigraphy is a safe and non-invasive technique that can be used to explore the entire body; thus, multifocal paragangliomas as well as malignant paragangliomas with local and distant metastasis can be detected. Because this technique is functional, it is highly useful to confirm recurrence or residual tumors, as well as to follow-up patients undergoing surgery. Paragangliomas can be familial and consequently this technique can be used for screening of familial cases. Recently, other nuclear imaging techniques, based on positron emission tomography (PET) technology, have been developed for the diagnosis of these tumors. Appropriately radiolabeled somatostatin analogs could potentially be used for the treatment of paragangliomas.