Advances in imaging and therapy of neuroendocrine tumours

A review in the European Journal of Endocrinology has highlighted the use of radionuclides to identify and treat neuroendocrine tumours.These diseases are rare but heterogeneous in their pathology and course. In general, surgery is the usual initial therapy, and is currently the only curative therapy. Radionuclides are increasingly important in diagnosis. For example, scintigraphy with 111In-pentetreotide is important in the identification and staging of gastro-enteropancreatic tumours. More conventional imaging techniques including helical CT, MRI and endoscopic or perioperative ultrasound is used for precise location and monitoring of lesions. Chromaffin cell tumours can be visualised using 123I-MIBG (meta-iodobenzylguanidine). More recently, PET scanning has been used to localise neuroendocrine tumours, particularly when other methods have failed, but its exact role and utility is yet to be defined. One area of considerable progress is the use of radionuclide therapy, in which a radioisotope is coupled to a molecule which specifically binds to tumour cells. The aim is to deliver an effective radiation dose to the tumour without damaging healthy cells. The principle is well established in treating thyroid tumours, but it has been expanded to cover a wide range of neuroendocrine tumours. For example, after 123I-MIBG has been used to identify a tumour - and also demonstrate that the radionuclide binds to it - then radioactive 131I-MIBG can be used to deliver radiotherapy. The efficacy has been confirmed in clinical trials in malignant carcinoid tumours, islet cell tumours, medullary thyroid carcinomas and chromaffin cell tumours. Radiolabelled somatostatin analogues have also been used therapeutically.The review stressed the need for a multidisciplinary approach to diagnosis and treatment. "As patients with malignant neuroendocrine tumours are rare, optimum management should be performed in centres with relevant experience and expertise," it said.Reference...