Objective: To evaluate the effect of 99Tcm-HYNIC-TOC imaging in localization of somatostatin receptor-positive tumors.
Methods: Forty-four patients were involved in this study, including 22 neuroendocrine tumors, 10 non-neuroendrocrine tumors and 12 benign diseases. All patients were confirmed by histopathologic diagnosis, and had clinical laboratory data, or 1-2 other imaging procedures. Regional, whole body and SPECT/CT (in positive cases) imagings were acquired at 1 and 4 hours after an intravenous injection of 370 MBq 99Tcm-HYNIC-TOC. 99Tcm-HYNIC-TOC imaging was compared with 111In-petetreotide imaging in 4 cases, and with 131I-MIBG imaging in 10 cases. 99Tcm-HYNIC-TOC imaging was performed before and after treatment in 1 non-Hodgkins lymphoma (NHL) patient.
Results: The positive imagings were observed in 19 of 32 cases. The sensitivity, specificity, and accuracy of 99Tcm-HYNIC-TOC imaging for somatostatin receptor-positive tumors are 82.6%, 100%, and 87.5%, respectively. The distribution in vivo of 99Tcm-HYNIC-TOC is similar to that of 111In-petetreotide, and showed high physiological uptake in liver, spleen, and kidneys. 99Tcm-HYNIC-TOC imaging demonstrated intense tumor sites uptake at 1 hour after injection, and revealed the lesions first in 6 patients among the imaging modalities, and more lesions that had not been revealed by 131I-MIBG imaging. Compared with imaging before treatment, 99Tcm-HYNIC-TOC imaging confirmed the tumor regression after treatment in 1NHL.
Conclusions: 99Tcm-HYNIC-TOC is promising for the diagnosis and localization of somatostatin receptor-positive tumors.