Radionuclide molecular imaging of human epidermal growth factor type 2 (HER2) expression may enable a non-invasive discrimination between HER2-positive and HER2-negative breast cancers for stratification of patients for HER2-targeted treatments. DARPin G3 is a small (molecular weigh 14 kDa) scaffold protein with picomolar affinity to HER2. The aim of this firstin-human study was to evaluate the safety, biodistribution and dosimetry of 99m Tc-(HE)3-G3.Methods. Three cohorts of patients with primary breast cancer (each including at least 4 patients with HER2-negative and 5 patients with HER2-positive tumors) were injected with either 1000, 2000 or 3000 µg of 99m Tc-(HE)3-G3 (287±170 MBq). Whole-body planar imaging followed by SPECT was performed at 2, 4, 6 and 24 h after injection. Vital signs and possible side effects were monitored during imaging and up to 7 days after injection.Results. All injections were well tolerated. No side effects were observed. The results of blood and urine analyses did not differ before and after studies. 99m Tc-(HE)3-G3 cleared rapidly from the blood. The highest uptake was detected in the kidneys and liver followed by the lungs, breasts and small intestinal content. The hepatic uptake after injecting with 2000 or 3000 µg was significantly (p<0.05) lower than the uptake after injecting with 1000 µg. Effective doses did not differ significantly between cohorts (average 0.011± 0.004 mSv/MBq). Tumor-to-contralateral site ratios for HER-positive tumors were significantly (p< 0.05) higher than for HER2-negative at 2 and 4 h after injection. Conclusions.Imaging of HER2 expression using 99m Tc-(HE)3-G3 is safe, well-tolerated and provides a low absorbed dose burden on patients. This imaging enables discerning HER2-positive and HER2-negative breast cancer. Phase I study data justifies further clinical development of 99m Tc-(HE)3-G3.

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Non-invasive radionuclide imaging of human epidermal growth factor receptor type 2 (HER2) expression in breast, gastroesophageal, and ovarian cancers may stratify patients for treatment using HER2-targeted therapeutics. Designed ankyrin repeat proteins (DARPins) are a promising type of targeting probe for radionuclide imaging. In clinical studies, the DARPin [99mTc]Tc-(HE)3-G3 labeled using a peptide-based chelator His-Glu-His-Glu-His-Glu ((HE)3), provided clear imaging of HER2 expressing breast cancer 2–4 h after injection. The goal of this study was to evaluate if the use of cysteine-containing peptide-based chelators Glu-Glu-Glu-Cys (E3C), Gly-Gly-Gly-Cys (G3C), and Gly-Gly-Gly-Ser-Cys connected via a (Gly-Gly-Gly-Ser)3-linker (designated as G3-(G3S)3C) would further improve the contrast of imaging using 99mTc-labeled derivatives of G3. The labeling of the new variants of G3 provided a radiochemical yield of over 95%. Labeled G3 variants bound specifically to human HER2-expressing cancer cell lines with affinities in the range of 1.9–5 nM. Biodistribution of [99mTc]Tc-G3-G3C, [99mTc]Tc-G3-(G3S)3C, and [99mTc]Tc-G3-E3C in mice was compared with the biodistribution of [99mTc]Tc-(HE)3-G3. It was found that the novel variants provide specific accumulation in HER2-expressing human xenografts and enable discrimination between tumors with high and low HER2 expression. However, [99mTc]Tc-(HE)3-G3 provided better contrast between tumors and the most frequent metastatic sites of HER2-expressing cancers and is therefore more suitable for clinical applications.

The paper presents the procedure for planning an experiment to create standard sets of reagents for a technetium-99m generator based on glucose derivatives. All stages are presented from researching the required quantities of a substance, a reducing agent, a stabilizer and auxiliary components to developing lyophilized kits and conducting quality control. The radiochemical purity of radiopharmaceuticals prepared on the basis of the developed kits ranged from 90.0 to 99.0%. We also showed the functional suitability of the developed preparations on C57B1/6j mice with an implanted malignant tumor -Lewis lung carcinoma. open Scientific RepoRtS | (2020) 10:5121 | https://doi.org/10.1038/s41598-020-61707-7 www.nature.com/scientificreports www.nature.com/scientificreports/ 0.2 Pa and a condenser temperature of −50 °C for at least 24 h, including 4 h of drying in the upper chamber. For the radiolabeling 4 mL of sodium pertechnetate solution [ 99m Tc] with an activity of 1.0 GBq was added to the obtained lyophilized samples and incubated at room temperature for 30 min. Radiochemical purity (RCP) control and the formation of the complex were monitored by TLC. D-glucosamine labeling. Preparation of lyophilizates of D-glucosamine substances was carried out as follows: 1 mL of a solution containing 20 mg of the glucose derivative, 0.140 mg of tin chloride and 200 μl of hydrochloric acid with a concentration of 0.05 mole was placed in a 10 mL vial. The vials without prior freezing were applied to a freeze-dryer at a pressure of 0.2 Pa and a condenser temperature of −50 °C for at least 24 h, including 4 h of drying in the upper chamber. For the radiolabeling 4 mL of sodium pertechnetate solution [ 99m Tc] with an activity of 1.0 GBq was added to the obtained lyophilized samples and incubated at room temperature for 30 min. Radiochemical purity (RCP) control and the formation of the complex were monitored by TLC. Scientific RepoRtS | (2020) 10:5121 | https://doi.www.nature.com/scientificreports www.nature.com/scientificreports/ particular, high-performance liquid chromatography (HPLC) are most frequently used for their determination 16 and for semiquantitative determination -thin-layer chromatography 17 .In our experiments, a high-pressure liquid chromatograph "Agilent 1200" with a refractometric and UV detectors and two types of columns ZORBAX NH2 and ZORBAX SB-C18 using different elution modes.As shown by our research method 1 using a UV detector, ZORBAX SB-C18 columns and gradient elution mode cannot be applied to preparations based on 5-thio-D-glucose and 1-thio-D-glucose, i.e. ascorbic acid, which in this mode of determination is not separated from the main substance and significantly increases the Name of the parameter RP "5-thio-Dglucose, 99m Тс" RP "1-thio-Dglucose, 99m Тс" RP «"Dglucosamine, 99m Тс" Volume of mixture in 1 flask Not more than 1 ml Not more than 1 ml Not more than 1 ml Scientific RepoRtS | (2020) 10:5121 | https://doi.

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The purpose of the study was a comparative research in the possibility of using the radiopharmaceuticals 99m Tc-Al 2 O 3 and 99m Tc-Nanocis for visualizing sentinel lymph nodes. The measurement of the sizes of 99m-Al 2 O 3 and 99m-Nanocis colloidal particles was performed in seven series of radiopharmaceuticals. The pharmacokinetics of 99m-Al 2 O 3 and 99m-Nanocis was researched on 50 white male rats. The possibility of the use of 99m-Al 2 O 3 and 99m-Nanocis for lymphoscintigraphy was studied in the experiments on 12 white male rats. The average dynamic diameter of the sol particle was 52-77 nm for 99m-Al 2 O 3 and 16.7-24.5 nm for 99m-Nanocis. Radiopharmaceuticals accumulated in the inguinal lymph node in 1 hour after administration; the average uptake of 99m Tc-Al 2 O 3 was 8.6% in it, and the accumulation of 99m Tc-Nanocis was significantly lower-1.8% (p < 0.05). In all study points the average uptake of 99m Tc-Al 2 O 3 in the lymph node was significantly higher than 99m Tc-Nanocis accumulation. The results of dynamic scintigraphic studies in rats showed that 99m Tc-Al 2 O 3 and 99m Tc-Nanocis actively accumulated into the lymphatic system. By using 99m Tc-Al 2 O 3 inguinal lymph node was determined in 5 minutes after injection and clearly visualized in all the animals in the 15th minute, when the accumulation became more than 1% of the administered dose. Further observation indicated that the 99m Tc-Al 2 O 3 accumulation reached a plateau in a lymph node (average 10.5%) during 2-hour study and then its accumulation remained practically at the same level, slightly increasing to 12% in 24 hours. In case of 99m Tc-Nanocis inguinal lymph node was visualized in all animals for 15 min when it was accumulated on the average 1.03% of the administered dose. Plateau of 99m Tc-Nanocis accumulation in the lymph node (average 2.05%) occurred after 2 hours of the study and remained almost on the same level (in average 2.3%) for 24 hours. Thus, the experimental study of a new domestic radiopharmaceutical showed that the 99m Tc-Al 2 O 3 accumulates actively in the lymph nodes several times as compared to the imported analogue and its practical application will facilitate intraoperative identification of sentinel lymph nodes.

Introduction. The purpose of this study was to evaluate the feasibility of using 99mTc-TG SPECT in the detection and staging of malignant lymphoma.Materials and methods.Fifteen patients with newly diagnosed malignant lymphoma  underwent 99mTc-TG SPECT. Six patients had Hodgkin’s lymphoma and 9 patients had aggressive forms of non-Hodgkin’s lymphoma (NHL): diffuse large B-cell lymphoma (7  cases), B-cell follicular lymphoma (1 case), and lymphoma from B cells in the marginal zone  (1 case). Stage IIA was diagnosed in 5 patients, stage IIB in 1, stage IIIA in 1, stage IVA in 4 and stage IVB in 4 patients.Results.Pathological 99mTc-TG uptake in lymph nodes was observed in 14 (93 %) of the  15 patients. In one patient, the enlarged submandibular lymph node (16 mm in size)  detected by CT was not visualized by 99mTc-TG SPECT. This false-negative result was likely  to be associated with increased accumulation of 99mTc-TG in the oropharyngeal region.  There were difficulties in the visualization of paratracheal, para-aortic and paracardial lymph  nodes. These difficulties were associated with a high blood background activity, which  persisted even 4 hours after intravenous injection of 99mTc-TG. Software-based SPECT and  CT image fusion allowed visualization of these lymph nodes. The pathological 99mTc-TG  accumulation in axillary, supraclavicular, infraclavicular and cervical lymph nodes was  observed most often. Extranodal involvement was seen in 9 patients. 99mTc-TG SPECT identified extranodal hypermetabolic lesions in 7 (78 %) of these patients. In one  patient, hypermetabolic lesion in the lung detected by 99mTc-TG SPECT was not detected on CT image. CT identified bone marrow involvement in the pelvic and scapula in 1 patient. The  use of 99mTc-TG SPECT allowed the visualization of hypermetabolic bone tissue lesions  in this patient (Figure 4). In addition, in a patient with intact bone tissue on CT, 99mTc-TG SPECT detected hypermetabolic lesions in the iliac bone.Conclusion.99mTc-1-Thio-D-glucose demonstrated increased uptake in nodal and  extranodal sites of lymphoma. The results indicate that SPECT with 99mTc-1-Thio-D-glucose is a feasible and useful tool in the detection and staging malignant lymphoma.

Abstract. Purpose: to study the potential utility of 1-thio-D-glucose labeled with 99m Tc for cancer imaging in laboratory animals. Materials and method: the study was carried out in cell cultures of normal CHO (Chinese hamster ovary cells CHO) and malignant tissues MCF-7 (human breast adenocarcinoma MCF-7). To evaluate the uptake of 99m Tc-1-thio-Dglucose in normal and tumor tissue cells, 25 MBq of 1-thio-D-glucose labeled with 99m Tc was added to the vials with 3 million cells and incubated for 30 min at room temperature. After centrifugation of the vials with cells, the supernatant was removed. The radioactivity in vials with normal and tumor cells was then measured. In addition, the study included 40 mice of C57B1/6j lines with tumor lesion of the right femur. For neoplastic lesions, Lewis lung carcinoma model was used. Following anesthesia, mice were injected intravenously with 25 MBq of 99m Tc-1-thio-D-glucose. Planar scintigraphy was performed 15 minutes later in a matrix of 512 512 pixels for 5 min. Results: when measuring the radioactivity of normal and malignant cells after incubation with 99m Tc-1-thio-D-glucose, it was found that the radioactivity of malignant cells was higher than that of normal cells. The mean values of radioactivity levels in normal and malignant cells were 0.3 ± 0.15 MBq and 1.07 ± 0.6 MBq, respectively. All examined animals had increased accumulation of 99m Tc-1-thio-D-glucose at the tumor site. The accumulation of 99m Tc-1-thio-D-glucose in the tumor was on average twice as high as compared to the symmetric region. Conclusion: The present study demonstrated that 99m Tc-1-thio-D-glucose is a prospective radiopharmaceutical for cancer visualization. In addition, high accumulation of 99m Tc-1-thio-D-glucose in the culture of cancer cells and in tumor tissue of animals demonstrates tumor tropism of the radiopharmaceutical.