Somatostatin receptor scintigraphy of non-neuroendocrine malignancies with 111In-pentetreotide
Limouris, G.S.; Rassidakis, A.; Kondi-Paphiti, A.; Triantafyllou, N.; Manetou, A.; Giannakopoulos, V.; Toubanakis, N.; Psyhojios, I.; Stavraka, A.; Vlahos, L.
Anticancer Research 17(3b): 1593-1597
1997
ISSN/ISBN: 0250-7005 PMID: 9179200 Document Number: 477442
In-111 pentetreotide is a new radiolabelled (Octreo-Scan 111, Mallinckrodt Medical BV, Petten) somatostatin analog with high affinity to somatostatin receptors (SR), introduced for the in vivo imaging of SR positive tissues. In an attempt to evaluate its clinical usefulness for tissue characterization in malignancies without neuroendocrine expression in parallel with histological and radiological examinations, specific scintigraphy was performed on brain (6 cases), thyroid (6 cases) and breast (9 cases) tumors, and in lymphomas (9 cases) and melanomas (6 cases). A dose of 111MBq of In-111 pentetreotide was injected i.v. to each patient and scintimages at 6 and 22 hours (for comparison) p.i. were obtained The primary lesion of the breast cancer population was imaged in all 9 cases as well as all the palpable axillary nodes in 4 cases. Three women with impalpable axillary lymph nodes scanned negative but had a positive biopsy. Both meningiomas were positive for SR scans; positive results were also obtained for the high grade astrocytoma and the craniopharyngioma: Two out of 6 patients with papillary thyroid cancer showed a marked radiotracer accumulation. Scintigraphy in all 5 lymphomas was positive for SR but did not detect the Tc-99m sulphur microcolloid (Lymphoscint, Solco, Basel, Switzerland) imaged lymph nodes in 5 melanomectomized patients. When judging the imaging results of these non-neuroendocrine malignancies definite conclusions should not be drawn since the number of studied cases polymorph, was small for every cancer histiotype; nevertheless SR scintigraphy does not seem to be reliable for tumor staging in non-neuroendocrine malignancies, but is more suitable for a tissue characterization and monitoring changes of SR expression during and after therapy.