Kidney Protection During Receptor Radionuclide Therapy

The discovery of somatostatin and the cloning and characterisation of its five receptor subtypes have led to many intriguing developments in clinical nuclear medicine. It was found that somatostatin administration resulted in inhibition of hormonal overproduction syndromes [5], which are found in several neuro-endocrine tumours. In addition, these tumours were shown to exhibit a high expression of somatostatin receptors [8-10]. Somatostatin itself can not be used for treatment purposes because it is metabolised very rapidly [5]. Analogues were made, of which octreotide was the most important. This eight- amino acid peptide has a longer plasma half-life and is now used for treatment of neuro- endocrine tumour-related hormonal overproduction syndromes [5]. The next step was the development of specific targeting and visualisation of the somatostatin receptor on the tumour cell surface. Octreotide was radiolabelled with the gamma-emitter 111In, using the attached chelator DTPA ([111In-DTPA0]octreotide, Octreoscan®). In 1994, Octreoscan® was approved for diagnostic use by the U.S. Federal Drug Administration in patients and it has become one of the most important imaging investigations in the initial identification and staging of gastroenteropancreatic neuro endocrine tumours [16-18, 234]. Patients with neuro-endocrine tumours have a number of therapeutic options (surgery, unlabelled somatostatin analogues, hepatic artery embolisation, ablation, chemotherapy and interferon-alpha), but these seldom result in cure [5, 235]. So, it was aimed to deliver therapeutic radioactivity to the tumour, adding a new therapeutic modality to the current available treatment options.

• View at Worldcat

Free Full Text ( Final Version , 3mb )