Comparative Evaluation Of¹¹C-MET PET/CT And MRI For Diagnosis Of Gliomas And Target Delineation Before Operation

Part oneComparative evaluation of¹¹C-MET PET/CT and MRI for diagnosis ofgliomas before operationObjective: The detection of the presence of gliomas and to determine the gliomas,boundaries before operation was very important for the tumor resection. In our study,we evaluate the value of¹¹C-MET PET/CT and MRI for diagnosis of gliomas beforeoperation and for differentiation the malignant and benign ones.Methods: We examined15patients prospectively with newly diagnosed gliomas basedon brain MRI before operations from2010-10to2011-6. Of all these patients, thegliomas were primary and without any treatment like operation、 radiation andchemotherapy.¹¹C-MET PET/CT was performed on these patients before operations,and then tumor resections. The time interval between MRI and PET/CT was no longerthan two weeks. Some patients were ruled out this study for no resections. Thencompared the PET/CT with their Pathology analysis to determine the evaluation of¹¹C-MET PET/CT and MRI for diagnosis of gliomas before operation. At last,11patientswere included. The final diagnosis references the Pathology analysis, which was thegolden standard.Results: Of all the eleven patients, ten was confirmed to be gliomas, except one glialcell hyperplasia. The sensitivity,specificity and accuracy of¹¹C-MET PET/CT andMRI for diagnosis of gliomas before operation were100%、100%、100%and100%、 0%、91%, respectively. The accuracy of¹¹C-MET PET/CT for differentiation themalignant and benign ones was73%（8/11）。Conclusion:¹¹C-MET PET/CT is more helpful than MRI for diagnosis of gliomasbefore operation, and can be used to differentiate malignant gliomas from benign onesto some extent.Part twoComparative evaluation of¹¹C-MET PET/CT and MRI for targetdelineationObjective: To evaluate the differences when defining target of gliomas on MRI and¹¹C-MET PET/CT, including the targets,（GTV、 CTV） volume、 the target ofcoincedence.Methods: We chose6patients for target delineation, then5physicians were called todetermine the target on these patienst,MRI and PET/CT pre-operation. Comparing thedifferences according to the previous methods.Results:①The volume sizes on MRI and¹¹C-MET PET/CT did not reach statisticalsignificance （Z=0.15，P=0.917）, but the TC（Target of coincedence）are significantlydifferent （TCGTV=0.58±0.12，t=8.930，P＜0.01；TCCTV=0.70±0.10，t=7.573，P＜0.01）;②And the target volume have no difference when were defined by different peopleneither on MRI or on PET/CT.③The D-value of GTV between MRI and PET/CTwhich were determined by different people did not reach statistical signigicance（t=-1.333，P=0.240＞0.01）, but the difference between PET/CT was smaller than the difference between MRI, they are27.6636cm3and40.3719cm3.Conclusion:①The boundary of gliomas which were defined on MRI and PET/CTwere different.②The target volume on MRI and PET/CT have no difference whendefined by different people;③The differences between PET/CT tend to be smaller thanMRI, which means that the show of target is relatively straightforward on¹¹C-METPET/CT.