ABSTRACT
Gastroenteropancreatic neuroendocrine tumours (GEP-NETs) are a rare type of cancer that can arise from the diffused endocrine system, located in the gastrointestinal (GI) tract (carcinoids) and in the pancreas (insular tumors). Approximately 2% of all malignant tumours of the gastrointestinal system are GEP-NETs which can express somatostatin receptors. 111In-pentetreotide (octreoscan) and 68Ga-DOTA NOC (68Ga-labelled [1,4,7,10- tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-Nal3-Octreotide) are the commonly used radiopharmaceuticals for imaging. Once localized using 68Ga DOTA NOC or octreoscan, these tumours can be successfully targeted with radiolabelled somatostatin analogues. This review focuses on common nuclear medicine procedures used in both imaging and treatment of these tumors.
ABSTRACT
The carcinoid tumor, argentaffinoma, is a member of a very exclusive neoplastic family known as neuroendocrine or amine precursor uptake and decarboxylation (APUD) tumors. Carcinoids have been found to arise from almost every organ and system derived from the primitive endoderm, but most frequently originated from the gastrointestinal tract, accounting for approximately half of all gastrointestinal endocrine tumors. Over 95% of all gastrointestinal carcinoids are located in only three sites: the appendix, rectum and small intestine. Irrespectively to their location, carcinoids are capable of producing various peptides. These tumors may present at different disease stages with either hormonal or hormonalrelated symptoms/syndromes, or without hormonal symptoms and may occur either sporadically or as a part of hereditary syndromes. Their clinical course is often indolent but can also be aggressive and resistant to treatment. This review provides a broad outline of progress that has been made in the elucidation of their clinical and laboratory diagnosis including recent advances in genetics, molecular biology, histopathology, biochemical markers, radiologic and scintigraphic imaging and endoscopy of gastrointestinal carcinoid tumors
Los tumores carcinoides, argentafinomas, son miembros de una familia particular de tumores conocida como familia de tumores neuroendocrinos o del sistema APUD (amine precursor uptake and decarboxilation: captación y descarboxilación de precursores de aminas). Los tumores carcinoides se originan en los órganos y sistemas derivados del endodermo primitivo, pero más frecuentemente en el tracto gastrointestinal, donde representan aproximadamente la mitad de todos los tumores endocrinos gastrointestinales. Más del 95% de todos los carcinoides gastrointestinales se localizan en tres sitios: el apéndice, el recto y el intestino delgado. Independientemente de su localización, los carcinoides pueden sintetizar varios péptidos. Estos tumores pueden presentarse en diferentes estadios patológicos con síntomas o síndromes hormonales o sin ellos, y pueden presentarse en forma esporádica o como parte de síndromes hereditarios. Su evolución clínica suele ser indolente pero también puede ser agresiva y resistente al tratamiento. Esta revisión describe el progreso realizado en el esclarecimiento de su diagnóstico clínico y de laboratorio e incluye avances recientes en genética, biología molecular, histopatología, marcadores bioquímicos, diagnóstico por imágenes radiológico y centellográfico y endoscopia de los tumores carcinoides gastrointestinales
Subject(s)
Humans , Somatostatin , Carcinoid Tumor , Neuroendocrine Tumors , Gastrointestinal Tract , Gastrointestinal NeoplasmsABSTRACT
Nuclear Endocrinology was the first clinical use of radionuclides, five decades ago. From those days to the present, nuclear medicine has a definitive role in the diagnosis of a great variety of clinical situations, from the very frequent thyroid nodule to the unusual neuroendocrine tumors, including parathyroid hyperfunctioning tissue. Radioiodine I131 still remains a very effective treatment for differentiated thyroid cancer and whole body scan with I131 in conjunction with seric Tyroglobulin level are the main follow-up strategies for these tumors. New techniques, like positron emission tomography (PET) and newer radiolabeled peptides, among others, will offer a molecular approach to the 21st century clinical nuclear medicine.
Se presentan las principales indicaciones actuales de los estudios radioisotópicos en endocrinología clínica, y su situación relativa con el resto de las técnicas de imagen no invasivas disponibles en nuestro medio. Se discuten brevemente las nuevas aplicaciones terapéuticas y su potencial desarrollo.