COMPARISON OF TC-99M SESTAMIBI AND IN-111 OCTREOTIDE IMAGING IN A PATIENT WITH EWINGS-SARCOMA BEFORE AND AFTER STEM-CELL TRANSPLANTATION

BACKGROUND. We report the use of two novel nuclide agents, Technetium- 99m (Tc-99)sestamibi (MIBI) and indium-111 (In-111) octreotide, in com parison with conventional computed tomography (CT) imaging in a patien t with metastatic Ewing's sarcoma (ES) before and after high dose chem otherapy with autologous peripheral stem cell transplantation (PSCT). MIBI is taken up actively by metabolically active tumor cells. Octreot ide, a somatostatin analog, binds specifically to somatostatin recepto rs. METHODS. The patient was a 20-year-old male with recurrent metasta tic ES to the lung. Before and sequentially after high dose chemothera py and PSCT, the patient was imaged with MIBI. Whole body planar and s ingle photon emission computed tomography (SPECT) images were obtained after the injection of 30 mCi of Tc-99 MIBI. Prior to PSCT the patien t was imaged with 6 mCi In-111 pentreotide. RESULTS. Conventional CT s cans also were performed. Initial CT revealed pulmonary metastasis in the right lower lobe along with multiple left pleural-based lesions. T hese lesions were visualized clearly with MIBI. Octreotide detected on ly the left lung involvement. Sequential MIBI scans after PSCT correla ted with tumor reduction in the right lung field and tumor progression in the left lung as well as the development of new pulmonary metastas is. These findings were confirmed on CT. CONCLUSIONS. MIBI imaging was highly concordant with CT scanning in the detection of metastatic ES. MIBI scanning holds promise for the direct detection of a variety of human malignancies, and may prove useful as a rapid whale body imaging modality. (C) 1997 American Cancer Society.