Imaging gastrointestinal tumours using vascular endothelial growth factor-165 (VEGF165) receptor scintigraphy

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Abstract
Background: Recent studies have shown that vascular endothelial growth factor (VEGF) receptor is overexpressed in vascular endothelial cells of various human tumours as well as in human tumour cells. The aim of this study was to evaluate the usefulness of scanning with VEGF165 labeled with 123I for tumor localisation in patients with gastrointestinal tumours. Patients and methods: Human recombinant VEGF165 was radiolabelled with 123I by electrophilic radioiodination using the chloramine T method. [123I]VEGF165 was administered intravenously [mean dose 184 ± 18 MBq (≤130 pmol; ≤5 µg) per patient] to 18 patients with gastrointestinal tumours. Dynamic acquisition was initiated immediately after administration and carried out until 30 min post-injection. Whole body images were done in anterior and posterior views at various time points. All patients underwent single-photon emission tomography imaging 1.5 h post-injection. Scanning with [123I]VEGF165 was compared with computed tomography and magnetic resonance imaging. Results: Intravenous injection of [123I]VEGF165 did not cause any side-effects. Binding of [123I]VEGF165 to primary tumours and metastases was visible shortly after injection. In patients with pancreatic adenocarcinomas, primary tumours were visualised in seven of nine, lymph node metastases in three of four, liver metastases in three of six and lung metastases in one of three. Cholangiocarcinomas were visualised by imaging in one of two patients. Hepatocellular carcinomas were visible by imaging in two of four patients. [123I]VEGF165 scans were weakly positive in one patient with abdominal schwannoma and in one patient with peritoneal carcinosis. Conclusions: These results indicate that scanning with [123I]VEGF165 can visualise gastrointestinal tumours and metastases expressing receptors for VEGF165. [123I]VEGF165 receptor scintigraphy may be useful for visualisation of tumour angiogenesis.