Technetium labeled small peptide radiopharmaceuticals in the identification of lung cancer

Globally, lung cancer has risen to the leading cause of cancer mortality in both sexes. Currently, the only potentially curable stage of the disease is the pulmonary nodule. Since numerous studies have documented that in any population of nodules only approximately fifty percent ultimately prove to be neoplastic, non-invasive evaluation of nodules to reduce surgical morbidity, mortality and cost is desirable. Recent nuclear medicine imaging modalities have shown promise in the accurate non-invasive characterization of pulmonary nodules. These new technologies exploit the biomolecular alterations of neoplastic cells. The somatostatin receptor is relatively over-expressed in pulmonary neoplastic tissue when compared to most benign tissue processes. A somatostatin analog-technetium ligand (Tc-99m depreotide) has shown significant promise in the rapid, convenient, accurate and cost effective characterization of lung nodules with conventional gamma camera systems. The development of this agent required synthesis of a somatostatin receptor ligand of high affinity for the receptor subtypes operative in pulmonary neoplasia and the incorporation of technetium without loss of pharmacore specificity.