Role of (111)In-DTPA-pentetreotide scintigraphy in accurate diagnosis of neuroendocrine gastroenteropancreatic tumors

Insulinoma in a third-trimester pregnant woman combined with pre-eclampsia: a case report and review of the diagnostic strategies

Insulinomas are rare neuroendocrine tumors with an incidence of 4 per 1,000,000 person-years, being even rarer during pregnancy. During pregnancy most cases are recognized or become symptomatic during the first trimester. A 29-year-old woman, primigravida, was hospitalized in the 38th gestational week due to slurred speech, weakness and slow reaction patterns. An electroencephalogram and computed tomography scan of the brain and blood samples were normal. Blood pressure was 170-145/110-95 mmHg, albuminuria was moderate and there was moderate edema of the ankles. Labor started spontaneously the third day, 62 h after of hospitalization, and the patient gave birth to a healthy girl with no neonatal problems. Fourteen hours after delivery, the patient became comatose and developed universal clonic seizures. At the same time plasma glucose was <1.1 mmol/l and the patient responded immediately to intravenous glucose. The patient was managed with frequent small meals and continuous intravenous glucose. Postpartum testing was consistent with insulinoma and diazoxide treatment was initiated. Endoscopic ultrasound with biopsy showed an insulinoma in the head of the pancreas. During surgical exploration, four separate insulinomas were removed from the head of the pancreas. The hypoglycemic episodes resolved and the glucose levels normalized. Following biochemical diagnosis of insulinoma, diagnostic imaging procedures encountered include endoscopic ultrasonography, magnetic resonance imaging and digital subtraction angiography. Of isotopic procedures, somatostatin receptor scintigraphy (Octreoscan) and newer receptor binding ligands can be used in non-pregnant women. Intraoperative ultrasonography seems mandatory. The present case demonstrates that seizure disorders in non-diabetic pregnant women may be caused by hyperinsulinemia-induced hypoglycemia due to insulinoma.

Receptor-Mediated Tumor Targeting with Radiopeptides. Part 1. General Concepts and Methods: Applications to Somatostatin Receptor-Expressing Tumors

Radiolabeled peptides have become important tools in nuclear oncology, both as diagnostics and more recently also as therapeutics. They represent a distinct sector of the molecular targeting approach, which in many areas of therapy will implement the old "magic bullet" concept by specifically directing the therapeutic agent to the site of action. In this three-part review, we present a comprehensive overview of the literature on receptor-mediated tumor targeting with the different radiopeptides currently studied. Part I summarizes the general concepts and methods of targeting, the selection of radioisotopes, chelators, and the criteria of peptide ligand development. Then, the >400 studies on the application to somatostatin/somatostatin-release inhibiting factor receptor-mediated tumor localization and treatment will be reviewed, demonstrating that peptide radiopharmaceuticals have gained an important position in clinical medicine.