The Diagnostic Value Of PET-CT For Pulmonary Occupying Lesion

Background:The lung cancer is one of the most common malignant tumors and its incidence is increasing year by year. The prognosis of lung cancer is closely related to its clinical stage. Early detection, early diagnosis and early treatment are very important for reducing the mortality of lung cancer.The diagnosis of lung cancer includes imaging, pathology, immunology and others. PET-CT, as the most advanced medical imaging devices, can obtain PET images, CT images and real-time integration of PET and CT images. It can reflect the organ's function, physiological condition, anatomical and pathological information, which are the important basis of the early diagnosis in lung cancer.18F-FDG PET-CT imaging plays an important role in the diagnosis of lung cancer, but there are still a few false positive and false negative cases. It seems that dual-time-point imaging and new imaging agent, such as 11C- choline, 18F-FLT, will improve the diagnostic value of PET-CT imaging. This study is divided into three parts. Part one:the diagnostic value of 18F-FDG PET-CT for pulmonary occupying lesion of different sizes. Part two:the diagnostic criteria and clinical value of dual-time-point 18F-FDG PET-CT with different metabolic levels. Part three:the value of the 18F-FDG PET-CT combined with 11C-choline in diagnosis of lung cancer and clinical decision making. Appendix:A prospective study about 18F-FDG PET-CT imaging in allorejection. Objective:To evaluate the diagnostic value of 18F-FDG PET-CT for pulmonary occupying lesion with different sizes.Materials and methods:194 patients with pulmonary occupying lesion between December 2008 and March 2011 at Qilu hospital of Shandong university are retrospective analyzed. All of them have the clear pathology or definite follow-up results (6-24months). Imaging methods:18F-FDG was produced by the GE MINItrace. The imaging-meter was GE Discovery STE16 ultra-highly integrated PET-CT system.According to the size on pulmonary window, all the occupying lesions were divided into five groups:t?1cm,1cm<t?2.0cm,2cm<t?3.0cm,3cm<t?5.0cm and t>5cm. The following signs in CT images were concerned lobulated,spiculated,vacuole sign, vessel convergence or pleural indentation.PET-CT images were analyzed by three attending physicians. ROI was placed by 3 experienced nuclear medicine physicians independently and the SUVmax was determined. We considered SUVmax over or equal with 2.5 as positive finding, while less than 2.5as negative finding.Statistical analysis:The statistical software SPSS13.0 was used. All dates were analyzed for significance by using the?2 test. value of P<0.05 were accepted as significance.Results:1. The diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 18F-FDG PET-CT, PET, and CT machine were 93.5%,87.3%,91.2%,92.7%,88.6%,87.8%,77.5%,84.0%,87.1%,78.6% and 87.8%,77.5%,84.0%,87.1%,78.6%. 2. The sensitivity of the t?1cm group was lower than other groups(P<0.05). The dual-time-point 18F-FDG PET-CT maybe can improve this situation,but there were no significant difference(P>0.05)3. The distribution location of benign and malignant lesions in the lungs was no significant difference. Size of lesion:the diameter of malignant> the benign group, malignant and benign lesions in diameter was significantly (P<0.05).4. Between benign and malignant groups, lobulation, speculation, vacuole sign, vessel convergence and pleural indentation have the significant difference (P <0.05), but there are still 10 cases of benign lesions apparent lobulated,speculated,vacuole sign, vessel convergence or pleural indentation.5. Respectively, the SUV between benign and malignant lesions in the same group was statistically significant different(P<0.05). There was significant difference in SUV between squamous carcinoma and adenocarcincinnma.Conclusion:1.18F-FDG PET-CT imaging plays an important role in the diagnosis of lung cancer.2. The sensitivity of the t?1cm group was lower than other groups. The dual-time-point 18F-FDG PET-CT maybe can improve this situation.3. The distribution location of benign and malignant lesions in the lungs was no significant difference. Lesion size seems that the malignant group is bigger than benign.4. Lobulation, speculation, and pleural indentation were related with the malignant lesions.However, CT diagnosis still has low sensitivity, accuracy, positive predictive value and negative predictive value.5. Respectively, the SUV between benign and malignant lesions in the same group was statistically significant. There was significant difference in SUV between squamous carcinoma and adenocarcincinnma. Objective:To evaluate the diagnostic criteria and clinical value of dual-time-point 18F-FDG PET-CT with different metabolic levels.Materials and methods:99 patients with pulmonary occupying lesion between December 2008 and March 2011 at Qilu hospital of Shandong university are retrospective analyzed. All of them have the clear pathology or definite follow-up results (6-24months). Imaging methods:18F-FDG was produced by the GE MINItrace. The imaging-meter was GE Discovery STE16 ultra-highly integrated PET-CT system. Early imaging time was after injection; delayed imaging was performed 120-180min after injection.According to the Maximum SUVearly, patients were divided into two groups: high metabolic (SUV>2.5,56 cases) and low metabolic (SUV?2.5,43 cases). PET-CT images were analyzed by three attending physicians. ROI was placed by 3 experienced nuclear medicine physicians independently and the maximum SUV delayed and SUV early were determined. Calculate retention index (RI) [RI= (SUV delayed-SUV early) X100/SUV early].We considered SUVmax over or equal with 2.5 as positive finding, while less than 2.5 as negative finding.Statistical analysis:The statistical software SPSS 13.0 was used. All dates were analyzed for significance by using the?2 test. value of P< 0.05 were accepted as significance. The area under the ROC curve (Az) evaluate the diagnostic value of each index, Az?0.7 has diagnostic value. Two groups were compared using t test.Results:1. In low metabolism group, SUVmax of different time point in benign and malignant lesions were compared, there were significantly different (P=0.003, P=0.002).?SUV and RI were calculated, both of which have significant difference (P<0.00, P=0.002).In high metabolic group, SUVmax of different time point in benign and malignant lesions were compared, there were significantly different (P=0.006, P=0.005).?SUV and RI were calculated. The different between?SUV was significantly different (P<0.001), The different between RI was no significant difference (P=0.156).3. In low metabolism group, RI> 5% as the diagnostic criteria, the diagnostic sensitivity, specificity and accuracy were 91.7%,74.2% and 79.1%. In high metabolic group, RI> 10% as the diagnostic criteria, the sensitivity and accuracy rate of 93.2%,79.2%, but specificity was only 16.6%.4. In low metabolism group, ROC curve analysis showed that Az of SUV delayed and SUV early were 0.79,0.81; Az of?SUV and RI were 0.76 and 0.77,but the difference was not statistically significant (P>0.05). In high metabolic group, ROC curve analysis showed that Az of SUV delayed and SUV early were 0.83,0.81; Az of?SUV and RI were 0.46 and 0.29,the difference was statistically significant (P<0.05).Conclusion1. Dual-time-point 18F-FDG PET-CT imaging plays an important role in pulmonary lesions with low metabolism. The diagnosis value was high when RI> 5% as the diagnostic criteria2. In high metabolic group, RI>10% as the diagnostic criteria, the sensitivity and accuracy rate of 93.2%,79.2%, but specificity was only 16.6%. Objective:To evaluate the value of the 18F-FDG PET-CT combined with 11C-choline in diagnosis of lung cancer and clinical decision making.Materials and methods:A total of 21 patients underwent lung occupying lesions were performed 18F-FDG and 11C-choline PET-CT imaging. All of them have the clear pathology or definite follow-up results (6-24months).PET-CT images were analyzed by three attending physicians. ROI was placed by 3 experienced nuclear medicine physicians independently and the SUVmax was determined. Clinical follow-up data was collected after the diagnosis.The statistical software SPSS13.0 was used. All dates were analyzed for significance by using the?2 test. value of P<0.05 were accepted as significance.Results:1. The 18F-FDG and 11C-choline SUVmax of malignant lesions were higher than those of benign lesions (P<0.05).2. The diagnostic sensitivity, specificity and accuracy of 18F-FDG PET-CT imaging were 90%,90.9% and 90.5%. The diagnostic sensitivity, specificity and accuracy of 11C-choline PET imaging with SUVmax>1.5 as the diagnostic criteria, were 80%,90.9% and 85.7%.3.18F-FDG with 11C-choline PET-CT imaging of the patients in this group, clinical decision of 4 patients (19%) was changed. Three of them are proved to be correct.Conclusion1.18F-FDG with 11C-choline PET-CT imaging in the diagnosis of pulmonary lesions appears to be effective, but because of the lack of large sample data, it couldn't be able to assess accurately. 2.11C-choline as a supplement 18F-FDG imaging agent plays an important role in the diagnosis of brain metastases.3. This study shows that the diagnostic value of 11C-choline PET imaging is effective with SUVmax>1.5 as the diagnostic criteria.Keywords:FDG; 11C-choline; pulmonary occupying lesion; clinical decision makingTransplantation is the most important treatment of patients with end stage renal and liver disease. Allograft rejection after transplantation is the most important cause of death. Biopsy is currently used for diagnosis of graft rejection as the gold standard, but the biopsy as a means of invasive procedures increased the infection, bleeding risk, and so on.The purpose of this study was to investigate the relationship between FDG uptake level of allograft and survival of graft. Perhaps we can find a noninvasive method to evaluate the acute allograft rejection after transplantation and the effect drug treatment. This study is divided into two parts. Part?:Investigate the effects of AMI on allograft survival and its relation to Treg.Part?:Investigate the relationship between FDG uptake level of allograft and survival of graft. We have finished the first part.Objective:Recently it has been reported that Astragalus membranaceus injection (AMI) inhibits immune responses, but whether it affects alloimmunity is not clear. It has been shown that the CD4+ CD25+ regulatory T cells (Treg) down-regulate immune responses. The aim of our study was to investigate the effects of AMI on allograft survival and its relation to Treg. Materials and methods:Allografted mice were administered AMI for 14 consecutive days with observations of graft survival. The specific recall response, the ratio of Treg, the expression of Foxp3 mRNA, and interleukin (IL)-10 secretion were measured by mixed lymphocyte reactions (MLR), FCM, reverse transcriptase-polymerase chain reaction, and radioimmunoassay, respectively.Results:AMI significantly prolonged allograft survival by up-regulating the Treg ratio and promoting Foxp3 expression (P<0.05).The ratio of Tregs, the expression of Foxp3 mRNA, and the IL-10 level in the AMI administration group increased from day 7, to reach a maximum at day 14, recovering to the initial level on day 21. No obvious difference was detected between the AMI and a cyclosporine group.Conclusion:1. Successfully established an allotransplantation model.2. AMI administered in vivo prolonged allograft survival associated with promotion of Treg activities.