Diagnostic and therapeutic applications of radiolabeled somatostatin analogs: current status in an oncology center.

From the prospective of a major oncology center in the United States, somatostatin analog radiopeptides currently have limited diagnostic and therapeutic utility. Diagnostic modalities utilitizing Somatostatin Receptor Imaging are now commercially available and the role of this type of method is currently being evaluated. Unlike the unique properties of thyroid tissue facilitating I-131 uptake, targeting of other tissues has required a carrier for the nuclide. Somastostatin peptide analogs have proved attractive based on the ubiquity of distribution and up-regulation in diseased tissue but prospective data is currently scarce. Interest in therapeutic applications of somatostatin analogs as carriers of yttrium, indium and more recently rhenium have resulted in trials with these agents both for endocrine and non-endocrine tumors. At this time, insufficient data exists to justify the indication of "first-line" therapy. The principles of Somatostatin Receptor Imaging and radiotherapy are discussed in this article along with the current status of these modalities in clinical practice as viewed by the author.