Comparison of Technetium-99m sestamibi and indium-111 octreotide imaging in a patient with Ewing's sarcoma before and after stem cell transplantation

BACKGROUND. We report the use of two novel nuclide agents, Technetium- 99m (⁹⁹Tc)sestamibi (MIBI) and indium-111 (In-111) octreotide, in comparison with conventional computed tomography (CT) imaging in a patient with metastatic Ewing's sarcoma (ES) before and after high dose chemotherapy with autologous peripheral stem cell transplantation (PSCT). MIBI is taken up actively by metabolically active tumor cells. Octreotide, a somatostatin analog, binds specifically to somatostatin receptors. METHODS. The patient was a 20-year-old male with recurrent metastatic ES to the lung. Before and sequentially after high dose chemotherapy and PSCT, the patient was imaged with MIBI. Whole body planar and single photon emission computed tomography (SPECT) images were obtained after the injection of 30 mCi of ⁹⁹Tc MIBI. Prior to PSCT the patient was imaged with 6 mCi In-111 pentreotide. RESULTS. Conventional CT scans also were performed. Initial CT revealed pulmonary metastasis in the right lower lobe along with multiple left pleural-based lesions. These lesions were visualized clearly with MIBI. Octreotide detected only the left lung involvement. Sequential MIBI scans after PSCT correlated with tumor reduction in the right lung field and minor progression in the left lung as well as the development of new pulmonary metastasis. 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 whole body imaging modality.