Combined use of 111In-labeled pentetreotide and three-step immunoscintigraphy with antichromogranin A monoclonal antibody in the diagnosis of pituitary adenomas.

Abstract

For various pituitary adenomas, it has been demonstrated that somatostatin receptor can be present. Pilot studies have shown that radio-indium labeled pentetreotide allows very good scintigraphic localization of somatostatin receptor-bearing cell masses. Recently, the presence of CgA in pituitary adenomas has also been demonstrated. MAb A11, raised against CgA, has been successfully used with a three-step ISG for the diagnosis of neuroendocrine tumors. Therefore the combined use of three-step ISG with MAb A11 and radiolabeled somatostatin can be useful in the diagnosis of pituitary adenomas. Twelve patients, 5 secreting (group A) and 7 nonsecreting (group B) pituitary adenomas, were enrolled in the study. All patients underwent three-step ISG, and, 2 wk later, scintigraphy with 111In-labeled pentetreotide (Octreoscan). Three-step ISG consisted of i.v. injection of 1 mg of biotinylated MAb A11 (first step), followed by 10 mg of avidin (second step) and [99mTc]PnAO-biotin (third step). Tomographic imaging were acquired for three-step ISG and Octreoscan at 2 and 4 h after radiotracer injection, respectively. The results are the following: 2 patients of group A (secreting tumors) had a positive three-step ISG, whereas all the patients but one of the same group had a positive pentetreotide study; all the patients of group B (nonsecreting tumors) had a positive three-step ISG and 4 had a positive pentetreotide scintigraphy. These data suggest the utility of the combined use of these techniques for a better diagnosis of pituitary adenomas.

• Authors: P Magnani, G Paganelli, A G Siccardi, C Songini, P Colombo, G Faglia, F Fazio
• Journal: Cell biophysics (Cell Biophys) Vol. 24-25 Pg. 307-13 ( 1994) ISSN: 0163-4992 [Print] United States
• PMID: 7736536 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal
• Chromogranin A
• Chromogranins
• Indium Radioisotopes
• Somatostatin
• pentetreotide

Topics

• Adenoma (diagnostic imaging)
• Adolescent
• Aged
• Antibodies, Monoclonal
• Child
• Chromogranin A
• Chromogranins (immunology)
• Female
• Humans
• Indium Radioisotopes
• Male
• Pituitary Neoplasms (diagnostic imaging)
• Radioimmunodetection
• Somatostatin (analogs & derivatives)