A Preliminary Study Of New Technique In High Field DWI For Assessment Of Early Treatment Response In Postoperative Patients With Glioma

Part one A preli_minary study of multiple b-value ADC maps for assessment of early treatment response in postoperative patients with gliomaObjective: The purpose of this study is to evaluate apparent diffusion coefficient?ADC? that have elicited from the enhancement region of different b-value ADC maps in multiple b-value DWI to assessment of early treatment response and detection of tumor progression.Metholds: This study analyzed different b-value ADC maps from 47 postoperative patients with a diagnosis of glioma,all of them accepted chemoradiotherapy after operation.MRI saning was executed when chemoradiotherapy finished,MRI saning include T1 WI, FLAIR, CE-T1 WI and multiple b-value DWI?b=0, 1000, 2000, 3000?s/mm²??. Contrast-enhanced lesions in CE-T1 WI were defined as regions of interest?ROI?,the different ADC were calculated from each ROIs in 5 differrent corresponding ADC maps. Thereafter,relative ADC?rADC?were calculated and compared the ADC between Different reaction types, Receiver operating characteristic?ROC?analysis was used to deter_mine the best cutoff values for predictors in the differentiation of progression from anther.Results: The rADC at b value of 3000 and 0 s/mm²?ADC3000/0??3000 and1000 s/mm²(ADC_3000/1000), 3000 and 2000 s/mm²(ADC_3000/2000) were significantly from Different response types[complete response, partial response,stable, progress:(ADC3000/0 rADC_mean=1.56±0.44, 60±0.28, 1.76±0.33,1.42±0.35 respectively, F=2.813,P=0.048)(ADC_3000/1000 rADC_mean= 1.49±0.27,1.41±0.38, 1.60±0.33, 1.24±0.35 respectively, F=4.164, P=0.010)(ADC_3000/2000 rADC_mean 1.51±0.31, 1.45±0.22, 1.40±0.28, 1.02±0.34 respec-tively, F=9.220, P=0.000)]. The area under the receiver operating characteristic curve of ADC Increasesed with the b value increases.When ADC_mean, rADC_mean at b=3000 and 2000 s/mm² ADC map were 408.65mm²/s and 1.124, The sensitivities and specificities were89.3%, 92.9%and 71.0%,77.4%, respectively.Conclusion :The ADC_mean and rADC_mean obtained at the enhancement region of high b-value ADC maps can assessment of early treatment response and differentiation of progression from another. It also could provide accurate information for identification of tumor progression,and it well be the preferred imaging for assessment of response in postoperative patients with glioma.Part two A Control study about assessment of response in postoperative patients with glioma by ADC which obtained at thehy perintense FLAIR regionObjective:The purpose of this study is to compare the distinction of different apparent diffusion coefficient?ADC? in detect tumor progression,which elicited from the enhancement and hyperintense FLAIR region.Metholds: This study accepted 47 postoperative patients with a diagnosis of glioma.All of them accepted chemoradiotherapy after operation.MRI saning was executed before and chemoradiotherapy finished,MRI saning include T1 WI, FLAIR, CE-T1 WI and multiple b-value DWI?b=1000, 2000,3000?s/mm²??,Calculate two groups of different ADC map[ADC( _3000/1000),ADC(_3000/2000)]. forty-seven patients appears 59 lesions have divided into progression?27 patients,30 lesions? and non- progression?20 patients,29lesions? by the Response Assessment Neuro-Oncology?RANO? Working Group criteria.The mean and _minimum ADC(CADC_mean and FADC_mean,CADC_min and FADC_min) were obtained at different regions of interest?ROI? in corresponding ADC maps,the ROIs were reference to CE-T1 WI and FLAIR respectively,then Calculate the relative ADC. each ADC between progression and non-progression groups were compared by using the unpaired Student t test or Wilcoxon rank sum test.ROC analysis was used to deter_mine the best cutoff values for distinguish progression from non-progression.Results :The ADC were significantly lower in the progression group than in the non-progression group no matter in enhancement or hyperintense FLAIR region,in enhancement region the r CADC_mean between progression group and non-progression group were: ADC(_3000/1000)1.24±0.35 and 1.53±0.31t=3.35 P=0.001,ADC(_3000/2000)1.02±0.34 and 1.45±0.28 t= 5.24 P=0.000; in enhancement region the r CADC_mean were: ADC( _3000/1000)1.40±0.26 and1.69±0.32 t=3.83 P=0.000,ADC(_3000/2000)1.22±0.31 and 1.64±0.33 t=5.07P=0.000. In addition to the r FADC_min was significantly lower in the progression group than in the non-progression group in ADC(_3000/1000)map?0.54±0.40 and 0.87±0.67,t=2.33, P=0.023?, the rest of the _minimum ADC have no significant difference in otherADCmaps?P>0.05?. The area under the receiver operating characteristic curve?AUC? of the ADC was similar between enhancement and hyperintense FLAIR region.The AUC were0.757 and 0.791 at the ADC( _3000/1000)map of r CADC_mean and r FADC_mean respectively,AUC were 0.862 and 0.847 at the ADC(_3000/2000)map. when r CADC_mean and FADC_mean were 1.12 and 487.45mm²/s in ADC(_3000/2000)map,the sensitivity, specificity, postive predictive value and negative predictive value were92.9%, 77.4%, 80.4%, 91.6% and 89.3%, 83.9%, 84.7%, 88.8%,respectively.Conclusion: The mean ADC at hyperintense FLAIR region in high b-value ADC map can detect tumor progression, The accuracies were similar to the enhancement region.It's mean that the ADC obtained at the hyperintense FLAIR region could raplace it obtained at the enhancement region in high b-value ADC map.Part three Differentiation of progression from non-progression in highgrade glioma?HGG? treated with chemoradiotherapy:comparison study between multiple b-valuediffusion-weighted imagingObjective: To explore the role of histogram analysis of apparent diffusion coefficient?ADC? maps obtained at multiple b-value?b=0, 1000,2000 and 3000?s/mm²?, respectively? diffusion-weighted?DW? imaging in the differentiation of progression from non-progression in HGG treated with chemoradiotherapy.Metholds: Forty-one consecutive patients with histopathologically proved HGG who had undergone concurrent chemoradiotherapy underwent diffusion weighted MR imaging with b values of 0, 1000, 2000 and 3000sec/mm², and corresponding ADC maps were calculated from hyperintense FLAIR lesions after completion of chemoradiotherapy.the fifth percentile?C5?in terms of cumulative histograms in different b-value ADC maps in multiple b-value DWI.C5 each ADC map between progression and non-progression groups were compared by using the unpaired Student t test.Receiver operating characteristic?ROC? analysis was used to deter_mine the best cutoff values and diagnostic accuracy for predictors in the differentiation of true progression from non-progression.Results: the C5 at all different b-value ADC maps were significantly lower in the progression group than in the non-progression group, C5 at ADC were? 1000/0??b=1000 and 0 s/mm²? 793.68±137.51 and 895.49±82.23?mm/s²?,ADC? 2000/0?632.54±103.85 and 770.69±96.35?mm/s²?, ADC? 3000/0?520.31±103.71 and 683.63±123.64?mm/s²?, ADC(_3000/1000)344.37±75.24 and 470.64±58.30?mm/s²?, ADC(_3000/2000)188.88±26.62 and 260.62±39.10?mm/s²?respectively, all of the P<0.01. Asignificant difference was found between the area under the receiver operating characteristic curve?AUC?of the C5 in different ADC maps,the AUC in each ADC maps were 0.717, 0.832, 0.909,0.933 and 0.937(ADC?1000/0?, ADC?2000/0?, ADC?3000/0?, ADC(_3000/1000), ADC(_3000/2000)).When C5 was 405.6 mm/s² in ADC(_3000/2000)map, the sensitivity,specificity, postive predictive value and negative predictive value were 90.9%,89.7%, 89.9%, 91.0%, respectively.Conclusion :The C5 obtained at the hyperintense FLAIR region in at all different b-value ADC maps can assessment of early treatment response and differentiation of progression from another,but the C5 at high b- value ADC map(ADC(_3000/2000)) was the most promising parameter in the detect progression.