Scintigraphic imaging of sarcomatous tumors with [In-111-DTPA-Phe-1]-octreotide

The objective of the present study was to investigate the efficacy of In-11 1-DTPA-octreotide (OC) for in vivo scintigraphic imaging of these relativel y uncommon tumors. Thirteen patients (9 males, 4 females, mean age 59 years ) with known sarcomatous lesions were studied. All patients had known lesio ns as demonstrated by previous investigation with other modalities, e.g. CA T, MRI. Following intravenous injection of in mu g of OC labeled with 2.8-4 .2 mCi In-111, planar imaging was done at 6 +/- 1 and 22 +/- 2 h, respectiv ely. Histologic verification was obtained in all cases, either from fine ne edle aspiration or from surgically removed tissue. Positive imaging was obs erved in 12/13 cases (92.3%). One scan was false-negative (7.7%). Occult le sions were demonstrated in two patients. The histologic typing and the scin tigraphy results were: fibrosarcoma (1+/1), embryonic rhabdomyosarcoma (1+/ 1), leiomyosarcomas (3+/3), liposarcomas (2+/2), uterine sarcomas (2+/2), H IV (-) Kaposi sarcoma (1+/1), osteosarcoma (1+/1), chondrosarcoma (1-/1) an d neurogenous sarcoma (1+/1). OC appears to have properties that lead to a new indication for its use. Other possible applications relate to the thera peutic use of octreotide either unlabeled or labeled with a beta-emitting r adionuclide, as well as its use in radioimmunoguided surgery. Regarding the latter, our preliminary results are encouraging. Copyright (C) 2000 S. Kar ger AG, Basel.