The Predictive Value Of Peritumoral RCBF And ADC Values In 1-year Progression-free Survival Of High-grade Gliomas

Objective:To explore the predictive value of peritumoral relative cerebral blood flow(CBF)and apparent diffusion coefficient(ADC)values in 1-year progression-free survival of high-grade gliomas using Three dimensional pseudo-continuous arterial spin labeling(3D-PCASL)and diffusion-weighted imaging(DWI)technique.Materials and Methods:1.35 patients with high-grade gliomas confirmed by postoperative pathology were collected(17 male cases,18 female cases,16 WHO III cases,19 WHO IV cases,mean age 51±14.42),the tumors were removed completely or partially,then underwent radiotherapy and chemotherapy after surgery,MR Follow-up exams were conducted every three months.Regarding operation time as the starting point of this research,the time of the progress within one-year follow-up after the operation or the time of death was taken as the study end point.The period from the start point to the end point was the patient’s 1-year progression-free survival time.If there was no progression or death during one year of follow-up,365 days was the 1-year progression-free survival time.2.All patients underwent conventional brain plain scan(axial T1WI,T2WI,Sagittal T1WI,coronal T2Flair),contrast enhanced T1WI,DWI and 3D-PCASL using 3.0T MR scanner before surgery.3.Images of CBF and ADC were obtained by postprocessing of ASL and DWI.4.In CBF images,the region of interest(ROI)were placed on 1cm region around the tumor and contralateral normal brain tissue on the most obvious contrast-enhancement slice Combined with the images of conventional plain scan and enhancement.Calculating rCBF value with CBF value of peritumor and contralateral normal brain tissue.In ADC images,the ROI were placed on 1cm region around the tumor and got the peritumoral ADC values.Three ROIs were randomly selected within the range of 1 cm around the tumor and the corresponding normal brain tissue on the opposite side.The mean value was obtained and the ROI area was about 50mm~2.When selecting the ROI,try to avoid the cerebral sulcus and pool.For tumors with a shift in the midline of the brain,the ROI of the contralateral normal brain tissue can be selected as the adjacent white matter area of the same plane.5.The peritumoral rCBF and ADC values of all patients were analyzed by the Receiver operating characteristic(ROC)curve,getting the cut-off value,the sensitivity and specificity.Kaplan-Meier method was used to draw the survival curve.The univariate analysis of clinical features,peritumoral rCBF and ADC parameters was performed using the Log-rank method,and the difference was statistically significant with P<0.05.Multivariate analysis of the clinical features,peritumoral rCBF and ADC parameters were conducted by Cox regression model.all statistical analyses were statistically significant with P<0.05.Results:1.Analysis of ROC curve:The area under curve of peritumoral rCBF value was0.81,the cut-off value was 1.862,the sensitivity and specificity were 76.5%and77.8%;The AUC of peritumoral ADC value was 0.73 with the cut-off value 0.741,the sensitivity 72.2%and specificity 70.6%.2.Kaplan-Meier survival analysis:For patients with high-grade gliomas,the survival curve significantly decreased when peritumoral rCBF>1.862,compared with that peritumoral rCBF≤1.862,and there were significant differences(P<0.001);when peritumoral ADC≤1.356×10-3mm~2/s,the survival curve decreased with significantly difference(P=0.013).Univariate analysis of the clinical features was conducted by Log rank method.The P values of age,gender and pathological grading were 0.196,0.075,0.433,and P<0.001 for total tumor resection.3.Multivariate analysis of Cox regression model:The P value of gender was0.063,HR was 3.191,95%CI was 0.939-10.845;the P value of total tumor resection was 0.003,HR was 5.422,95%CI was 1.760-16.697;P<0.001 for peritumoral rCBF,HR was 10.294,95%CI was 2.830-37.442;The P value of peritumoral ADC was0.395,HR was 0.418,95%CI was 0.056-3.121.Conclusion:1.The prediction efficiency of peritumoral ASL-rCBF and DWI-ADC values of high-grade gliomas for whether or not the patient has progressed for 1 year were moderate,of which only peritumoral ASL-rCBF values could be used as an independent predictor of 1-year PFS.And the ASL technique is completely non-invasive.Therefore,the peritumoral ASL-rCBF parameters have a higher predictive value of 1-year PFS for high-grade gliomas patients.2.In clinical features,the extent of tumor resection is also an independent predictor of one-year’s progression-free survival in high-grade gliomas.1-year PFS was significantly longer in patients with complete tumor resection than in those with partial tumor resection.