[Metastatic gastroenteropancreatic neuroendocrine tumours: 111In-pentetreotide and PET-FDG imaging]

We present a patient with previous history of neuroendocrine tumour in the head of the pancreas, well differentiated and treated surgically. Two years later, there was suspicion of relapse. An endoscopy, CT scan and 111In-pentetreotide scintigraphy were performed. The 4 hour image showed two uptake lesions in the liver and the peripancreatic region. However, these focal uptakes had disappeared in the 24 hour image. In view of this result, a PET-FDG scan was carried out, showing two hypermetabolic lesions. The biodistribution of 111In-pentetreotide may be influenced by various parameters, including the time of scanning, and may show neuroendocrine tumours without somatostatin receptors in relapses. PET-FDG is an interesting tool to help characterise these cases.