ADC值在原发性脑淋巴瘤放疗疗效中的预测价值

Predictive value of ADC value in radiotherapy of primary brain lymphoma

目的探讨扩散加权成像中表观扩散系数(apparent diffusion coefficient,ADC)值对原发性脑弥漫大B细胞淋巴瘤放疗疗效的预测价值。材料与方法收集宁夏医科大学总医院2009至2017年经临床和病理活检证实为弥漫大B细胞淋巴瘤的20例原发性脑淋巴瘤患者(无免疫缺陷病史)资料,通过放疗前后轴位T1WI增强病灶强化最大径变化计算出肿瘤消退率进而将病灶分为完全缓解(complete remission,CR)组和非完全缓解(非CR)组,测量病灶放疗前的最小ADC(ADC_(min))值、平均ADC(ADCmean)值、最大ADC(ADC_(max))值,采用独立样本t检验验证放疗前CR组与非CR间有无差异,采用Pearson相关性分析评价肿瘤ADC值与肿瘤消退率的相关性,进而利用受试者工作特性曲线求得ADC值的阈值。结果放疗前ADC_(min)值与ADCmean值在CR组与非CR组间差异有统计学意义(P<0.05),而ADC_(max)在两组间差异无统计学意义。ADC_(min)值、ADCmean值与肿瘤消退率有相关性(r=0.630、0.460,P=0.000、0.005),且分别大于0.602×10^(-3) mm^2/s、0.800×10^(-3) mm^2/s时患者放疗疗效,能在放疗周期完成后达到CR的效果。结论 ADC_(min)值及ADCmean值可以作为预测原发性脑淋巴放疗疗效的指标。

Objective:To investigate the predictive value of pretherapeutic apparent diffusion coefficient(ADC)value in the diffusion-weighted imaging for radiotherapy of primary brain lymphoma.Materials and Methods:20 patients,from 2009 to 2017,in General Hospital of Ningxia Medical University clinical examination without history of immunodeficiency disease were collected,which were clinically and biopsy confirmed as diffuse large B cell lymphoma.The maximum diameter of enhanced lesion were measured from axial enhanced T1WI,before and after the radiotherapy,via which the tumor regression rate can be calculated.Then the primary brain lymphoma can be divided into two groups,called as complete remission(CR)group and non-complete remission(non-CR)group,via tumor regression rate.The minimum ADC(ADCmin)value,the average ADC(ADCmean)value,the maximum ADC(ADCmax)value of the lesion before radiotherapy were measured,the various ADC value in two groups were analyzed using statistical approach.Results:The difference between ADCmin value and ADCmean value before radiotherapy was statistically significant(P<0.05)between CR group and non-CR group,while ADCmax value had no significant difference between the two groups.ADCmin value and ADCmean value correlated with tumor regression rate,while each value were greater than 0.602×10^-3 mm^2/s,0.800×10^-3 mm^2/s,the patients can be achieved CR effect after the completion of the radiotherapy cycle.Conclusions:ADCmin value and ADCmean value can be used as imaging biomarkers to predict the radiotherapy efficacy of the primary brain lymphoma.