Threshold Analysis Of Extent Of Resection For Patients With Grade ? Gliomas Using MRI

Background and objective Glioma,a kind of malignant tumor,is the most common tumor of the central nervous system.According to statistics,there are 6.6 was diagnosed as gliomas per 100,000 people in the United States every year.The World Health Organization(WHO)classifies glioma into grade I-IV,grade I or II is LGG(low-grade glioma)and grade ? or IV is high grade glioma(HGG).The higher the tumor grade,the worse the prognosis.The 2018 National Comprehensive Cancer Network(NCCN)guidelines suggest that HGG should be maximally and safely removed to achieve a better prognosis.At present,there is no threshold of extent of resection(EOR)which is the most relative with prognosis have been proposed by a authoritative research.In order to remove the tumor as much as possible and preserves neural function at the same time,many neurosurgeons have made great efforts.Such as the application of multi-mode preoperative MRI technology mainly includes PWI,DTI,DWI,MRS,etc,which is conducive to more accurate preoperative diagnosis of lesion boundaries.In addition,use of the intraoperative real-time monitoring technology,such as awakening anesthesia,somatosensory evoked potential,intraoperative cortical electrical stimulation,cortical motor evoked potential,intraoperative functional neuronavigation,intraoperative ultrasound,intraoperative magnetic resonance,intraoperative fluorescein sodium guidance,etc,makes it possible to remove the tumor safely in the maximum range possible.Due to the low incidence of grade ? gliomas,grade ? gliomas and grade IV gliomas are often collectively referred to as HGG,there are few studies related to grade ? gliomas,the best imaging sequence related to tumor volume has not been determined.It is significant to approach the threshold of EOR and the MRI sequence which is the best correlation with tumor volume.Methods and materials A retrospective study of 96 cases were performed who was diagnosed as glioma of Grade ? Gliomas at Dalian Municipal Central Hospital,during the period from 2010 to 2015.The gender,age,preoperative Karnofsky performance status,tumor location,edema,postoperative chemoradiotherapy and EOR of gliomas were respectively investigated.Preoperative and postoperative MRI images were collected,and the postoperative and postoperative MRI DICOM images were imported into Materialise Mimics Innovation Suite Research 21.0 software to calculate the tumor volume.EOR of gliomas =(preoperative tumor volume-postoperative residual tumor volume)/preoperative tumor volume.EOR of gliomas of enhanced T1 WI and FLAIR was calculated respectively.The postoperative survival time and the postoperative survival status of the patients were investigated by telephone follow-up etc.Survival time was defined as the time between the first glioma resection and death due to glioma progression.Complete data were obtained for patients who were followed up to the present point of death,and deletion data were obtained for those who remained alive.Statistical methods SPSS23.0 software was used for statistical analysis.OS was used as the dependent variable,and Kaolain-Meier method was used to univariate analyze the relation of clinical factors and survival time,and log-rank method was used for test.And then multifactor analysis were conducted with Cox multivariate regression analysis,P<0.05 was considered statistically significant.Results A total of 96 patients were included,including 54 males and 42 females.There were 35 cases were located in eloquent brain areas(such as language area,movement area,thalamus,saddle area,brain stem,pineal gland area,etc.),and 61 cases were located in noneloquent brain areas(such as cerebellar hemisphere,frontal lobe,parietal lobe,temporal lobe and occipital lobe).Postoperative radiotherapy was performed in 93 patients(97%)and chemotherapy in 54 patients(56%).The median preoperative volume,postoperative volume,and resection rate of Flair sequence were 114.4cm3, 30.8 cm3,and 66.5%,respectively.The tumor of 62 patients showed enhancement in the enhanced T1 WI sequence.The median preoperative volume,postoperative volume and EOR of the enhanced T1 WI sequence were 18.4cm3,3.1cm3 and 91%,respectively.The 1-year,3-year and 5-year survival rates were 82%,31% and 12%,respectively,for all patients.The results of univariate analysis showed that patients with Age <50(P=0.032),preoperative KPS ?80(P<0.0001),mild edema(P=0.005),postoperative chemotherapy(P<0.0001)and T2 Flair EOR<68%(P<0.0001)had better prognosis.Cox multivariate regression analysis showed that age(P=0.008)? edema(P=0.003)?postoperative chemotherapy(P<0.0001)and T2 Flair EOR(P=0.004)were independent factors of prognosis for grade ? glioma patients.Conclusion T2 Flair showed a better correlation with tumor volume.T2 Flair EOR was an important prognostic indicator for grade ? glioma patients.Patients with Flair EOR ?68% had a better prognosis.