Neuroendocrine tumours are cancers that begin in specialised cells called neuroendocrine cells. These cells have traits similar to those of nerve cells and hormone-producing cells. Neuroendocrine tumours, while rare, can occur anywhere in the body. Most affect the cardiothoracic region, eg lungs, appendix, small intestine, pancreas as well as the rectum. There are many types of neuroendocrine tumours: some grow slowly while others develop very rapidly.

Neuroendocrine tumors are characterised by abundant production of somatostatin receptor 2, a naturally circulating hormone that is an important target for scientists studying new treatment approaches.

Peptide Receptor Radionuclide Therapy (PRRT) is the most commonly used treatment for refractive neuroendocrine cancers, delivering cancer-killing radioactive substances directly to tumour sites. This treatment provides symptomatic relief, stopping or slowing tumour growth and improving overall survival for patients. It is a form of molecular therapy that features a protein (called a peptide) which targets cancer cells and which is similar to the naturally circulating hormone, somatostatin. The peptide is mated with a small amount of radioactive material, or radionuclide. They form a radiopharmaceutical called a radiopeptide (177Lu-DOTA-EB-TATE). Injected into a patient, this radiopeptide travels in the bloodstream, finds and then binds to neuroendocrine tumor cells, before delivering a targeted high dose of radiation directly to the cancer cells.
PPRT pharmacokinetics, pharmacodynamics improved

Together with collaborators at the Peking Union Medical College Hospital, the Chinese Academy of Medical Science, Professor Shawn Chen Xiaoyuan of the Department of Diagnostic Radiology, Yong Loo Lin School of Medicine at the National University of Singapore (NUS), has managed to improve the pharmacokinetics (i.e. the absorption and movement of drugs into, through and out of the body) and effectiveness of PPRT, while reducing its dosage and toxicity. The researchers did this by introducing a truncated Evans blue molecule onto octreotate peptide (denoted as 177Lu-DOTA-EB-TATE).

"The EB part allows reversible binding of 177Lu-DOTA-EB-TATE to blood albumin and extends its half-life in the blood, and thus provides an extended therapeutic time window, and improved treatment efficacy over Lutathera," said Prof Chen, who holds concurrent appointments at the NUS Departments of Chemical and Biomolecular Engineering, and the Department of Biomedical Engineering, Faculty of Engineering. Lutathera is a radioactive medication used to treat neuroendocrine cancers.

Molecular Imaging Homepage