The PET tracer 5-([11C]methyloxy)-L-tryptophan (5-(11)CMTP) was prepared by nucleophilic fluorination and alkylation reaction via a two-step procedure in order to develop specific tumor probe. The biodistribution and microPET imaging of 5-(11)CMTP were executed. The results unveiled that the overall radiochemical yield with no decay correction was (14.6 ±7.2) %, the radiochemical purity was more than 95% and high uptake and long retention time of 5-(11)CMTP in liver, kidney and blood were observed but low uptake in brain and muscle were found, furthermore, high uptake of 5-(11)CMTP in tumor tissue was observed. It seems that 5-(11)CMTP will be a potential amino acid tracer for tumors imaging with PET.
Amino Acids ; Animals ; Neoplasms ; diagnostic imaging ; Positron-Emission Tomography ; Radioactive Tracers ; Tissue Distribution ; Tryptophan ; analogs & derivatives

OBJECTIVETo investigate the tumor targeting efficacy of (18)F-AlF-NOTA-PRGD2, a novel radiotracer of Arginine-glycine-aspartic acid (RGD) peptides.

METHODS(18)F-AlF-NOTA-PRGD2 was synthesized in one-step by conjugating NOTA-PRGD2 with (18)F-AlF at 100 degrees celsius;. The tumor targeting efficacy and in vivo biodistribution profile of (18)F-AlF-NOTA-PRGD2, following intravenous injection via the tail vein, were evaluated in a nude mouse model bearing subcutaneous U87MG glioblastoma xenograft by radioactivity biodistribution assessment, PET/CT and microPET/CT.

RESULTSNOTA-PRGD2 was (18)F-fluorinated successfully in one-step with a yield of 17%-25% within 15-20 min. Radioactivity biodistribution study confirmed the tumor-targeting ability of (18)F-AlF-NOTA-PRGD2 in the tumor-bearing mice. At 1 and 2 h following injection, (18)F-AlF-NOTA-PRGD2 uptake in the tumor reached 4.14∓1.44 and 2.80∓1.18 % ID/g (t=1.910, P=0.070) with tumor/brain ratios of 2.95∓0.61 and 5.21∓2.62, respectively (t=-1.686, P=0.167). Both PET/CT and microPET/CT were capable of showing the radioactivity biodistribution of (18)F-AlF-NOTA-PRGD2 in the mouse model and clearly displayed the tumor, but microPET/CT showed a much better image quality.

CONCLUSION(18)F-AlF-NOTA-PRGD2 prepared by one-step radiosynthesis can selectively target to the tumor, demonstrating its potential as a good radiotracer for tumor imaging.

Animals ; Cell Line, Tumor ; Fluorine Radioisotopes ; Glioblastoma ; diagnostic imaging ; Humans ; Mice ; Mice, Nude ; Oligopeptides ; Positron-Emission Tomography ; methods ; Radioactive Tracers

OBJECTIVETo trace magnetically labeled MSCs transplanted into the rat livers by magnetic resonance imaging (MRI).

METHODSFeridex and DAPI labeled rat mesenchymal stem cells (MSCs) were injected via portal veins into carbon tetrachloride treated rats. MRI was performed with a clinical 1.5 T MRI machine immediately before the MSCs injection and at h 1, d 3, d 7, and d 14 after the injection, and then the signal-to-noise ratio (SNR) was measured. MRI findings were compared with the liver histopathologies after the slides were stained with fluorescence dye and Prussian blue.

RESULTSThe SNR for liver was 1.10+/-0.26 at hour 1, 8.18+/-1.55 at day 3, 11.08+/-1.30 at day 7, and 14.15+/-1.02 at day 14 respectively. Within 7 days after the MSCs transplantation, the SNRs of the livers were significantly lower than those before the transplantation (P less than 0.05). Histologically, the blue fluorescent particles under the fluorescence microscopy matched in distribution with the iron particles on the Prussian blue stained slides.

CONCLUSIONThe magnetically labeled MSCs transplanted into livers give rise to an obvious signal decrease, and can be tracked with a 1.5 T clinical MRI machine for up to 7 days after MSCs transplantation.

Animals ; Image Enhancement ; methods ; Liver ; pathology ; Magnetic Resonance Imaging ; Male ; Mesenchymal Stem Cell Transplantation ; Radioactive Tracers ; Rats ; Rats, Wistar

OBJECTIVEUsing radioactive nano tracer with different sizes (average diameter were 50, 80 and 100 nm) and dosages (0.01 and 0.02 ml) in the thyroids of rabbits, to study the drainage of thyroid to cervical lymph nodes (LNs) in rabbits and to provide experimental evidence for the choice of ideal sizes and dosages of radioactive Nano tracer for the sentinel lymph node biopsy (SLNB) in thyroid cancer patients.

METHODSThirty adult rabbits were randomly divided into six groups (50 nm - 0.01 ml, 50 nm - 0.02 ml, 80 nm - 0.01 ml, 80 nm - 0.02 ml, 100 nm - 0.01 ml, 100 nm - 0.02 ml of (99m)Tc-Sb(2)S(3)) with five rabbits in each group. A total of 60 sides of thyroids were included. The mean number of LNs with radioactivity, the initial, the strangest and the lasting time of radioactivity in LNs in each group were measured.

RESULTSOne to three LNs were identified in one side neck of rabbits, totally 86 LNs. Most of LNs with radioactivity existed in level VI, counting for 75.6% (65/86). (99m)Tc-Sb(2)S(3) with 50 nm particles was significantly better than that with 80 nm or 100 nm particles with regarding the initial and the strangest radioactive time of (99m)Tc-Sb(2)S(3) in LNs (P < 0.05). There were no significant difference in the mean number of LNs with radioactivity, the initial, the strangest and the lasting time of radioactivity between the dosages of 0.01 ml and 0.02 ml of (99m)Tc-Sb(2)S(3) with same size of particles (P > 0.05).

CONCLUSION(99m)Tc-Sb(2)S(3) with 50 nm particles, in the dosage of 0.01 ml or 0.02 ml, could be good choice for SLNB of thyroid cancer.

Animals ; Lymph Nodes ; diagnostic imaging ; Male ; Nanostructures ; Neck ; diagnostic imaging ; Rabbits ; Radioactive Tracers ; Radionuclide Imaging ; Thyroid Gland ; diagnostic imaging

The validity of (99m)Tc-YIGSR, a novel receptor radio-tracer, in imaging the Ehrlich ascites tumor was evaluated. YIGSR, a pentapeptide of laminin, was labeled with (99m)Tc by using a bifunctional chelator S-Acetly-NH(3)-MAG(3). The MIBI was labeled with (99m)Tc by following the kit instruction. The mice of tumor group were intravenously injected 1-2 mCi of (99m)Tc-YIGSR or (99m)Tc-MIBI via caudal vein, immobilized and imaged under a Gamma camera. The same procedure was performed in mice of blockade group, in which the unlabeled YIGSR was previously injected to block the receptor-recognition sites, and inflammation group serving as control. The reverse-phase Sep-Pak C(18) chromatogram was found to have an essentially complete conjugation between YIGSR and S-Acetly-NH(3)-MAG(3). The conjugated YIGSR could be radio-labeled successfully with (99m)Tc at room temperature and neutral pH, with a radio-labeling yield of 62%. Without the chelator S-Acetly-NH(3)-MAG(3), the YIGSR was labeled with (99m)Tc at an efficiency of 4%. The imagological study revealed obvious tumor accumulation of (99m)Tc-YIGSR 15 min after the injection, and the uptake peaked after 3 h with a tumor-to-muscle ratio (T/M) of 11.36. The radio-tracer was slowly cleared up and resulted in a T/M of 3.01 at the 8th h after the injection. As for blocked group, the tumor uptake of radiotracer was significantly lower, with the highest T/M being 4.61 after 3 h and 0.89 after 8 h. The T/M was 3.72 at the 3rd h and 1.29 at the 8th h after the (99m)Tc-YIGSR injection in the inflammatory group. The T/M was significantly higher in tumor group than in inflammatory group or control group (P<0.001). In the 99mTc-MIBI group, the T/M was 1.40 at the 3rd h and 0.55 at the 8th h after the injection, which showed a significant difference as compared with (99m)Tc-YIGSR (P<0.001). It is concluded that YIGSR can be successfully radiolabelled by using S-Acetly-NH(3)-MAG(3). (99m)Tc-YIGSR has many advantages in tumor imaging, such as quick and clear visualization, high sensitivity and specificity, and satisfactory target/non-target ratio (N/NT). It promises to be tumor radio-tracer.
Animals ; Carcinoma, Ehrlich Tumor ; diagnostic imaging ; Mice ; Radioactive Tracers ; Radionuclide Imaging ; Radiopharmaceuticals ; Receptors, Laminin ; metabolism ; Technetium Tc 99m Mertiatide ; Technetium Tc 99m Sestamibi

The validity of (99m)Tc-YIGSR, a novel receptor radio-tracer, in imaging the Ehrlich ascites tumor was evaluated. YIGSR, a pentapeptide of laminin, was labeled with (99m)Tc by using a bifunctional chelator S-Acetly-NH(3)-MAG(3). The MIBI was labeled with (99m)Tc by following the kit instruction. The mice of tumor group were intravenously injected 1-2 mCi of (99m)Tc-YIGSR or (99m)Tc-MIBI via caudal vein, immobilized and imaged under a Gamma camera. The same procedure was performed in mice of blockade group, in which the unlabeled YIGSR was previously injected to block the receptor-recognition sites, and inflammation group serving as control. The reverse-phase Sep-Pak C(18) chromatogram was found to have an essentially complete conjugation between YIGSR and S-Acetly-NH(3)-MAG(3). The conjugated YIGSR could be radio-labeled successfully with (99m)Tc at room temperature and neutral pH, with a radio-labeling yield of 62%. Without the chelator S-Acetly-NH(3)-MAG(3), the YIGSR was labeled with (99m)Tc at an efficiency of 4%. The imagological study revealed obvious tumor accumulation of (99m)Tc-YIGSR 15 min after the injection, and the uptake peaked after 3 h with a tumor-to-muscle ratio (T/M) of 11.36. The radio-tracer was slowly cleared up and resulted in a T/M of 3.01 at the 8th h after the injection. As for blocked group, the tumor uptake of radiotracer was significantly lower, with the highest T/M being 4.61 after 3 h and 0.89 after 8 h. The T/M was 3.72 at the 3rd h and 1.29 at the 8th h after the (99m)Tc-YIGSR injection in the inflammatory group. The T/M was significantly higher in tumor group than in inflammatory group or control group (P<0.001). In the 99mTc-MIBI group, the T/M was 1.40 at the 3rd h and 0.55 at the 8th h after the injection, which showed a significant difference as compared with (99m)Tc-YIGSR (P<0.001). It is concluded that YIGSR can be successfully radiolabelled by using S-Acetly-NH(3)-MAG(3). (99m)Tc-YIGSR has many advantages in tumor imaging, such as quick and clear visualization, high sensitivity and specificity, and satisfactory target/non-target ratio (N/NT). It promises to be tumor radio-tracer.
Carcinoma, Ehrlich Tumor/*radionuclide imaging ; Radioactive Tracers ; Radiopharmaceuticals/*diagnostic use ; Receptors, Laminin/*metabolism ; Technetium Tc 99m Mertiatide/*diagnostic use ; Technetium Tc 99m Sestamibi/*diagnostic use

OBJECTIVE: Using radioactive Nano tracer at different sizes and doses in the Larynx of rabbits, to study the roles of them in the sentinel lymph node (SLN) biopsy in rabbits and to provide experimental evidences for the choices of ideal size and dose of radioactive Nano tracer of the sentinel lymph node biopsy in Laryngeal cancer patients. METHOD: thirty rabbits were randomly divided into six groups with five rabbits in each group. After 50 nm--0.01 ml, 50 nm--0.02 ml, 80 nm--0.01 ml, 80 nm--0.02 ml,100 nm--0.01 ml, 100 nm--0.02 ml of 99mTc-sulfur Colloid were separately injected into the Larynx, the number of SLNs, the initial and strongest radioactive time of SLNs, and the lasting time of radioactivity was obtained. RESULT: One to three SLNs were identified in one rabbit, so there were totally forty-five SLNs, which in the areas of II, III and IV. The group of 50 nm--0.02 ml had the largest number of SLNs and there were significant differences between the group of 50 nm-0.02 ml and 100 nm--0.01 ml. In the six groups, the group of 50 nm--0.02 ml was the earliest group of detecting the initial and strongest radioactivity of SLNs,which the time were 49.20 s and 178.60 s; the group of 100 nm--0.01 ml was the latest group of detecting the initial and strongest radioactivity of SLNs, which the time were 235.80 s and 311.20 s. Each group had radioactivity more than 30 minutes. CONCLUSION The group of 50 nm--0.02 ml was the best group, because it moved fast and had a higher rate of uptake in lymphangio. Moreover, the radioactivity time was more than 30 minutes. It was the ideal size and dose of SLN biopsy in larynx.
Animals ; Larynx ; diagnostic imaging ; Lymph Nodes ; diagnostic imaging ; pathology ; Male ; Nanostructures ; Rabbits ; Radioactive Tracers ; Radionuclide Imaging ; Sentinel Lymph Node Biopsy ; methods

OBJECTIVETo analyze the characteristic of the radioactive lymph node with metastatic disease and to explore the method of the localization of sentinel lymph node (SLN) with radionuclide in N0 clinically laryngeal and hypopharyngeal cancer.

METHODSFourty-five patients with T1-T4 and clinically N0 laryngeal and hypopharyngeal cancer were recruited. For each patient a peritumoral submucosal injection of 99mTc-labeled sulfur colloid (99mTc-SC) was performed and lymph node mapping was performed by lymphoscintigraphy two hours afterward. The SLN was localized by a handheld gamma probe intraoperatively 10-12 hours after the injection. All hot lymph nodes accumulating activity were harvested and initially termed sentinel nodes. Selective neck dissections were performed for all patients. The specimen of SLN was sent to the pathologist for the following analysis: formal paraffin embedded section, consecutive section and immunohistochemistry assay. The results was compared to the remaining lymphadenectomy specimen. Resection of the primary tumour depended on the location and the T classification.

RESULTSSLNs were identified in 41 of 45 patients with 51 necks, SLNs had occult metastases in 13 cases, 15 necks with SLN-positive of these 13 cases, there was one false negative case, they were found in non-SLNs of neck specimens. Each neck side was considered a single case. SLN identification rate was 92.7%, sensitivity was 93.7%, false-negative rate was 6.3%, and accuracy was 98.0%. In 11 (73.3%) of these SLN-positive necks, the SLN with the highest counts contained tumor; harvesting the first-three nodes with the highest radioactive counts, which could all patients with occult metastatic disease.

CONCLUSIONSExcision of the first-three SLNs with the highest radioactive counts can accurately judge the presence or absence of the cervical lymph nodes metastases in patients with the clinically N0 laryngeal and hypopharyngeal cancer.

Adult ; Aged ; Female ; Humans ; Hypopharyngeal Neoplasms ; diagnostic imaging ; pathology ; Laryngeal Neoplasms ; diagnostic imaging ; pathology ; Lymph Nodes ; diagnostic imaging ; pathology ; Male ; Middle Aged ; Radioactive Tracers ; Radionuclide Imaging ; Sentinel Lymph Node Biopsy ; methods ; Technetium Tc 99m Sulfur Colloid

This study was to clarify whether Behcet's disease (BD) could be classified into the spondyloarthropathy (SpA) complex. It was undertaken on 58 patients with BD (BD group), 56 patients with SpA (SpA group), and 3 patients who concurrently satisfied the criteria for BD and SpA (BDSpA group). The clinical parameters and known susceptible HLA antigens were compared between BD group and SpA group. In addition, 3 patients in BDSpA group were reviewed. The prevalence of definitive sacroiliitis (SI) in BD group and SpA group was 46.4% and 5.2%, respectively. However, none had a definitive SI in healthy controls. Enthesitis was observed in 3.4% of BD group and in 50% of SpA group. The patterns of eye involvement were different between these two groups. HLA-B27 was negative in all 49 patients of BD group, whereas it was positive in 67.9% of SpA group. The prevalence of HLA-B51 was 51.7% in BD group, and that in SpA group was 21.4%. One patient in BDSpA group was considered to have concurrent BD and ankylosing spondylitis (AS). Another patient was closer to AS, and the third to BD. Conclusively, it seems that BD could not be classified into the SpA complex.
Adult ; Behcet Syndrome/*classification/immunology/pathology ; Eye/pathology ; Female ; HLA-B Antigens/analysis/immunology ; HLA-B27 Antigen/analysis/immunology ; Humans ; Lumbar Vertebrae/pathology/radiography ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Pelvis ; Radioactive Tracers ; Sacroiliac Joint/pathology/radiography ; *Spondylarthritis/immunology/pathology ; Tomography, Emission-Computed, Single-Photon