Safety, biodistribution, and dosimetry of myocardial imaging agent 99Tc(m)N-NOET in healthy volunteers / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the safety, biodistribution, and dosimetry of myocardial perfusion imaging agent 99Tc(m)N-NOET in 10 healthy volunteers.</p><p><b>METHODS</b>744-792 MBq of 99Tc(m)N-NOET was injected to each volunteer. Safety parameters and adverse event was measured in 24 hours of injection. Biodistribution was studied by whole-body imaging 1, 30 minutes, 1, 2, 4, 8, and 24 hours after the injection of 99Tc(m)N-NOET. The estimation of dosimetry was based on the standard medical internal radiation dose method using MIRDOSE 3.0 analysis program. Myocardial single photon emission computed tomography (SPECT) imaging was performed at 1 and 4 hours after injection.</p><p><b>RESULTS</b>No undesirable effects were reported by the subject during 24 hours after injection of 99Tc(m)N-NOET. No clinically significant changes were found in vital signs (heart rate, blood pressure, and electrocardiogram). No biochemical aspects and serology changes were measured. The myocardial SPECT imaging was clear. Cardiac uptake of 99Tc(m)N-NOET was as high as 2.68% at 2 hours after injection. The heart to lung ratio was more than 1 from 30 minutes after injection, reaching a maximum of 1.91 +/- 0.53 at 2 hours after injection. Radiation dosimetry calculations indicated an effective absorbed dose of 1.28 x 10(-5) Sv/MBq. The dosimetry in each main organ is lower then 50 mGy given 740 MBq of 99Tc(m)N-NOET in once imaging.</p><p><b>CONCLUSIONS</b>99Tc(m)N-NOET exhibits high cardiac uptake and low estimated effective absorbed dose. It's a safe myocardial perfusion imaging agent.</p>

Preliminary clinical application of 99Tcm-HYNIC-TOC imaging in somatostatin receptor-positive tumors / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the effect of 99Tcm-HYNIC-TOC imaging in localization of somatostatin receptor-positive tumors.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>99Tcm-HYNIC-TOC is promising for the diagnosis and localization of somatostatin receptor-positive tumors.</p>