Role of nuclear medicine in the diagnosis and therapy of neuroendocrine tumors

Autor: Fazio, Nicola, Del Vecchio, Silvana, Camera, Luigi, Storto, Giovanni, Salvatore, Marco, Reznek, R H, Andrea Rollandi, Gian, Biscaldi, Ennio
Jazyk: angličtina
Rok vydání: 2005
Předmět:
Zdroj: Cancer Imaging
ISSN: 1470-7330
1740-5025
Popis: Neuroendocrine tumours (NETs) are very rare diseases characterised by a high degree of histological and clinical heterogeneity. They can be silent (even producing some hormones) or clinically evident as a result of local growth and/or hormonal production. The diagnostic and therapeutic approach to patients with NETs should be multidisciplinary. A medical oncologist should coordinate a group of experts, including a radiologist, surgeon, nuclear medicine specialist, pathologist, clinical pathologist, gastroenterologist, endocrinologist and radiotherapist, who should discuss all of the cases and define therapeutic strategies rather than single therapy indications. The therapeutic programme depends on a profound knowledge of the disease and the patient. It should begin with appropriate staging using an octreoscan, computed tomography or magnetic resonance, with ultrasound and bone scan if indicated, and serum chromogranin-A assays. Secondly, the biological characteristics of the tumour (particularly its proliferation index) should be known. If possible, the disease should be reassessed after 1 or 2 months without anti-tumoral therapy in order to evaluate the growth rate. In well-differentiated NETs with a high density of somatostatin 2 and 5 receptors, we are studying the feasibility and efficacy of a multimodal strategy including debulking with hepatic chemoembolisation and/or surgery for primary tumours or metastases, combined with systemic treatment with a somatostatin analogue and interferon, and followed by targeted radiotherapy with 90Y-DOTATOC or 177Lu-DOTATATE. About 40 patients have been treated in this way, 15 of whom received a combination of surgery, chemoembolisation, 90Y-DOTATOC and hormonal therapy in various sequences. The preliminary results indicate that an increasing number of patients with NETs can avoid potentially toxic treatment such as chemotherapy.
Islet cells tumours are a range of rare neoplasms of neuroendocrine origin arising in or close to the pancreas. The normal islet cells of Langerhans in the pancreas contain B-cells (which secrete insulin), A-cells (which secrete glucagon), D-cells (which secrete somatostatin), D1-cells (which secrete pancreatic polypeptide) and D2-cells (which secrete vasoactive intestinal peptide). The majority (85%) of islet cell tumours secrete one or more of these hormones, or other substances not normally found in the adult pancreas (although often present in the foetal pancreas), notably gastrin.
Carcinoids account for 25% of all primary small bowel tumours. They are 10 times more common in the ileum than in the jejunum and duodenum, rarely arising from Meckel’s diverticulum. With a typically slow growth pattern, carcinoids are asymptomatic in their early development or may present with vague abdominal pain or dyspepsia for 5–7 years. Despite significant improvements in diagnostic techniques and operative mortality, the survival of patients with primary malignant tumours of the small bowel has changed little since the late 1960s. In effect many patients have advanced tumours at surgery because of delayed diagnosis. These delays may derive from a variety of reasons, including failure of physicians to order appropriate diagnostic tests and failure of radiologists to reach the correct diagnosis. The small bowel is a potential source of unexplained abdominal symptoms and appropriate radiologic tests are needed. In this work we report our experience of the study of small bowel tumours, particularly the detection of carcinoids. In our opinion the preoperative imaging demonstration of a malignant tumour is essential. In small bowel tumour evaluation we favour computed tomography (CT). The use of CT is controversial in gastrointestinal (GI) tube study, but new technical and clinical improvements in spiral CT studies have substantially changed the approach in GI tract imaging. CT enteroclysis is considered to be an efficient technique for small bowel study: the forced distension of the bowel wall allows good detection of the lesions in tumoral diseases of the intestine and a complete imaging technique to stage intestinal neoplasms.
Databáze: OpenAIRE
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