Synthesis of opiate receptor radioligand 11C-carfentanil and its biodistribution in rats / 中华核医学杂志

Objective To establish an automatic synthesis method for 11C-carfentanil (CFN) as an novel opiate receptor radioligand and study its biodistribution in rats. Methods 11C-Triflate-CH3 was bubbled into 0.5 mg precursor desmethyl-CFN (which was dissolved in 0.15 ml DMSO) to generate 11C-CFN in a V-tube at room temperature. Sep-Pak C2 column was used for purification of 11C-CFN, which was eluted by 3ml binary system aqueous solution, 10 ml water thrice, and then I ml ethanol. The biodistribution (% ID/g) of 11C-CFN in SD rats was studied. SPSS 13.0 was used for statistical analysis. Non-normal distribution data were analyzed using nonparametric test. Results The synthesis time for 11C-CFN was 20 min (end of bombardment, EOB). The synthesis yield was (35.5 ± 2.2) % on average (n = 12, uncorrected)with the radiochemical purity over 98%. Biodistribution study in rats showed that the tracer had a high brain uptake, rapid blood clearance, and a metabolic pathway via liver and kidney. The highest tracer uptake was in thalamus (4.26 ± 0.89) % ID/g and striatum (4.05 ± 1.08) % ID/g at 5 min after injection, followed by cerebral cortex (2.63±0.89) %ID/g, pons (2.26 ±0.57) % ID/g, hippocampus (2. 17 ±0.55) %ID/g and cerebellum (2. 15 ±0.39) %ID/g. Conclusions The automatic synthesis of 11C-CFN is fast and reliable, and this radioligand can be used for opiate receptor imaging.

18F-FDG uptake changes in the brain functional loop in patients with refractory obsessive compulsive disorder / 中华核医学杂志

Objective To investigate the glucose metabolic pattern of brain functional loop in patients with refractory obsessive compulsive disorder (OCD) using 18 F-FDG PET.Methods Eight patients with refractory OCD and 8 age- and gender-matched healthy volunteers underwent 18F-FDG PET brain imaging.SPM software was used for image post-processing and quantitative analysis.Correlation analysis between 18F-FDG uptake and Yale-Brown obsessive compulsive scale(Y-BOCS) score was performed.Results Compared with the controls,the glucose metabolism of bilateral frontal cortices ( including the rectal gyrus,orbital gyrus and cingulate gyrus),left thalamus,right temporal lobe and bilateral cerebellum in refractory OCD patients increased significantly ( Zmax =3.45 - 5.80,all P ＜ 0.001 ).Bilateral motor cortices and bilateral parietal lobes (BA7),however,showed decreased glucose metabolism (Zmax =3.44 - 4.46,all P ＜0.001 ).Y-BOCS score was positively correlated with the glucose metabolism of the bilateral anterior cingulate cortex (Zmax =3.77,3.48 and 2.97,all P ＜ 0.01 ).Conclusions There is a characteristic metabolic pattern of increased glucose utilization in the fronto-striato-thalamic loop and decreased glucose utilization in bilateral motor cortices and parietal lobes in patients with OCD.The glucose metabolism in the anterior cingulate cortex might serve as a quantitative parameter for the assessment of the severity of OCD.

Accuracy of 18F-FDG PET/CT for lymph node staging in non-small-cell lung cancers / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This retrospective study evaluated the diagnostic accuracy of 2-(F18)-fluoro-2-deoxy-D-glucose-positron emission tomography ((18)F-FDG-PET)/computed tomography (PET/CT) in the preoperative diagnosis of metastatic mediastinal and hilar lymph node in patients with non-small-cell lung cancer (NSCLC).</p><p><b>METHODS</b>A total of 39 patients received preoperative (18)F-FDG PET/CT and the postoperative biopsy. We compared preoperative PET/CT scan results with corresponding intraoperative histopathalogic findings in 39 NSCLC patients. The sensitivity, specificity, accuracy, positive and negative predictive value of (18)F-FDG PET/CT were assessed.</p><p><b>RESULTS</b>Histopathologic examination confirmed metastasis in 57 out of the 208 excised lymph nodes; 23 of the 57 nodes were mediastinal and hilar lymph nodes. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of PET/CT in the preoperative diagnosis of mediastinal lymph node metastasis in NSCLC patients were 65%, 96.8%, 92%, 78.5% and 90%, respectively.</p><p><b>CONCLUSIONS</b>PET/CT scan showed good accuracy in the preoperative diagnosis of mediastinal and hilar lymph node metastasis in the patients with NSCLC. We recommend that PET/CT scanning be used as a first-line evaluation tool for tumor diagnosis, therapy evaluation and follow-up.</p>

Pharmacokinetics and biodistribution of 11C-HupA in the normal animal / 中华核医学杂志

Objective HupA is one of the potential drugs which can be used to treat Alzheimer's disease(AD).The aim of this study was to explore the pharmacokinetics and biodistribution of HupA in vivo by using 11C-HupA.Methods A total of 25 SD rats were studied.They were divided into 5 groups (5 rats in each group).All had intravenous injection of 22 MBq(in0.2 ml)11C-HupA through tail vein.Dynamic im-aging Was acquired from 5 to 90 minutes after injection.Venous blood and organ activities were collected at 5,15,30,60.and 90 minutes after injection.Percentage activity of injected dose per gram of tissue(%ID/g)was calculated to characterize the biodistribution of tracer in different brain regions: frontal,apical, temporal,occipital,cerebellum,hippocampus,striatum,thalamencephalon, and brain stem, Variance analysis using SPSS 11.5 software was performed and compared among the study groups.Results 11C-HupA was character-istic for its quick clearance from blood,with half time T1/2 of (14.61±1.77) min,and clearance rate (CL)macokinetics of 11C-HupA in rats corresponded to a one-compartment model.with an activity curve(area 11C-HupA distribution in different brain regions,being greater in cerebral cortex,hippocampus,hypothala-mus and brain stem. Conclusions Pharmacokinetic study of 11C-HupA in brain was fast.convenient and showed high specificity and sensitivity.Its ability to quantitatively evaluate brain function and its character-istic distribution in mice provided some evidence for monitoring therapy in AD patients.

Malignant tumor with false negative 18F-FDG PET image / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the FDG uptake characteristics, the factors affecting 18F-FDG uptake and the extra CT diagnostic value of 18F-FDG PET/CT scan in the malignant tumor with false negative 18F-FDG PET image.</p><p><b>METHODS</b>The data of PET/CT image in 17 patients with various kinds of cancers were reviewed and analyzed by visual observation and semi-quantity analysis ( SUV). The results were compared with the CT and histopathological diagnosis, respectively.</p><p><b>RESULTS</b>Of 6 well-differentiated HCC patients confirmed by histopathological diagnosis, one had two lesions in the right lobe of the liver. One of these two lesions showed low FDG uptake on 18F-FDG PET scan and low density on CT scan. The other one was not shown on either 18F-FDG PET or plain CT scan. But on enhanced CT scan, these two lesions were found to be inhomogeneous with high density at arterial phase. The false negative 18F-FDG PET images of one gastric signet ring cell carcinoma in the gastric fundus with right adnexa metastasis, 3 renal cell carcinoma, one greater omentum and peritoneal metastatic adenocarcinoma and one well-differentiated prostate cancer were caused by normal physical uptake in the digestive tract or FDG retention in the urinary system due to normal excretion. The size of three metastases was smaller than or equal to 1 cm in diameter, however, two primary lesions of these metastases showed high FDG uptake and only one was negative on either 18F-FDG PET or CT scan. In this series, 68.8% of the primary tumors and 66.7% of metastases were found to show abnormal density on CT scan, and 31. 2% of the primary tumors and 33. 3% of metastases were not detectable on either PET or CT images.</p><p><b>CONCLUSION</b>False negative 18F-FDG PET in malignant tumor may be correlated with the pathologic type, differentiation degree and the lesion size. Combining CT information with PET or paying attention to the scan methods during 8 F-FDG PET examination may reduce the rate of false negative 18F-FDG PET diagnosis in various kinds of malignant tumors.</p>

Study on glucose metabolic rate in non-small cell lung cancer patients with blood stasis syndrome and non-blood stasis syndrome / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the difference of glucose metabolic rate in non-small cell lung cancer (NSCLC) patients with blood stasis syndrome and with non-blood stasis syndrome.</p><p><b>METHODS</b>Whole body positron emission tomography (PET) and functional agent 2-[fluorine-18] fluorine-2-deoxy-glucose (18FDG) were used to detect the 18FDG uptake value in regions of interest (ROI) in tumor tissue of patients.</p><p><b>RESULTS</b>In patients with same pathologic type, the maximum and mean standardized uptake value (Max SUV and Mean SUV) were significantly higher in the blood stasis group than those in the non-blood stasis group (P < 0.01); it also showed the same in patients with NSCLC of phase I, II and III (P < 0.05), but the 18FDG uptake rate was obviously enhanced in patients of phase IV (P < 0.01).</p><p><b>CONCLUSION</b>The glucose uptake in NSCLC patients of blood stasis syndrome was higher than that in those with of non-blood stasis syndrome.</p>