(dtpa-phe(1))-octreotide and ACTH-Syndrome--Ectopic

Topics: ACTH Syndrome, Ectopic; Adult; Bronchial Neoplasms; Carcinoid Tumor; Cushing Syndrome; Diagnosis, Differential; Humans; Indium Radioisotopes; Male; Octreotide; Pentetic Acid; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The differential diagnosis and management of Cushing's syndrome remain difficult, particularly for ectopic adrenocorticotropin (ACTH) syndromes resulting from small bronchial carcinoids. We report the case of a 41-year-old man with ectopic ACTH-dependent Cushing's syndrome. Two computed tomography scans of the thorax were normal and magnetic resonance imaging of the chest showed a 6-mm hyperintense T1-weighted area close to the left pulmonary hilus, interpreted as probably vascular by the radiologists. An [111In-DTPA-D-Phe1]octreotide scintigraphy scan demonstrated a positive image for somatostatin receptors in exactly the same location and surgery confirmed the presence of a small ACTH-secreting carcinoid tumour in the upper left lung lobe which was resected. Surgery cured the hypercorticism of the patient. The differential diagnosis of Cushing's syndrome and the procedure for localisation of an ACTH source are discussed.

Topics: ACTH Syndrome, Ectopic; Adult; Carcinoid Tumor; Humans; Indium Radioisotopes; Lung Neoplasms; Male; Octreotide; Pentetic Acid; Radionuclide Imaging; Radiopharmaceuticals

This report describes a technique that increases the specificity of 111In-pentetreotide as evaluated in a patient with ectopic Cushing syndrome.. Two separate SPECT studies were performed with different pharmacologic protocols, both including treatment with cold octreotide. The imaging protocol provides acquisitions at 4 and 24 hr after injection. The quantitative approach was based on the ROI activity (manually designed) of an area of pathological lung uptake (ROI-T) versus background (ROI-NT). Histological, histochemical and specific mRNA measurements confirmed the presence of an SSR2 receptor carcinoid in the lung.. The time course of ROI-T/ROI-NT is a linear increase between 4 and 24 hr. Washout with cold octreotide diminished the ROI-T activity content and the saturation protocol increased ROI-T/ROI-NT, confirming the specific nature of the uptake.. Displacement and saturation protocols in 111In-pentetreotide imaging demonstrated the specificity of tumor binding.

Topics: ACTH Syndrome, Ectopic; Adult; Carcinoid Tumor; Female; Humans; Indium Radioisotopes; Lung Neoplasms; Octreotide; Pentetic Acid; Radiopharmaceuticals; Receptors, Somatostatin; Sensitivity and Specificity; Time Factors; Tomography, Emission-Computed, Single-Photon

Topics: ACTH Syndrome, Ectopic; Adult; Bronchial Neoplasms; Carcinoid Tumor; Humans; Indium Radioisotopes; Male; Octreotide; Pentetic Acid; Radionuclide Imaging; Radiopharmaceuticals