不同b值DWI对宫颈癌放化疗疗效的评估价值

The comparative study of different b-value combinations on evaluating the response to radiochemotherapy in cervical cancer

目的探讨不同b值弥散加权成像(DWI,diffusion-weighted imaging)对宫颈癌放化疗疗效的评估价值。方法48名接受全程放化疗治疗的宫颈癌患者分别在治疗前、治疗2周后、治疗4周后及治疗结束后进行盆腔常规MRI及DWI扫描,每次扫描均测量肿瘤的ADC值,所有ADC值均由b=0,600s/mm2和b=0,1000s/mm2两组ADC图得出。根据治疗结束后的结果将患者划分为完全有效组(CR)、部分有效组(PR)及无效组(SD),并根据ROC曲线比较两组ADC图评估宫颈癌放化疗疗效的价值。结果治疗2周及4周后CR组的ADC值提高百分比在两组ADC图中均高于RP及SD组;治疗结束后,CR组的ADC值在两组ADC图中均高于RP及SD组;其中治疗4周后及治疗结束后高b值组(b=0,1000s/mm2)区分CR组与PR/SD组的能力高于低b值组(b=0,600s/mm2)(P<0.05);低b值组所测数据的标准差均大于高b值组。结论高b值DWI评估宫颈癌放化疗疗效的整体价值高于低b值DWI,且数值更为稳定。

Objective To investigate the influence of different b-value combinations on evaluating the response to radio- chemotherapy in cervical cancer. Methods Forty-eight cervical cancer patients treated with radiochemotherapy received conventional MRI and DWI prior to therapy and after 2-week therapy, 4-week therapy, and therapy completion. Dynamic changes of apparent diffusion coefficients （ADC） were observed and compared. All the ADCs were calculated from b= 0.600 s/mm^2 and h=0.1000 s/mm^2. Treatment response was classified as complete response （CR）, partial response （PR） and stable disease （SD）, which were determined according to the changes in turnout size after therapy completion. Results The increased ADC percentage was higher in CR group than those in PR and SD groups after two weeks and four weeks therapy at both ADC maps; after therapy completion, the ADC values of CR group were significantly higher than PR and SD groups at both ADC maps; the discriminatory capability for differentiation of CR and PR, SD groups was significantly higher for high b-value combination （0.1000 s/mm^2） than those for low b-value combination （0.600 s/mm^2） after four- week therapy and therapy completion （ P〈0.05） ; the SD （standard deviation） of ADCs or increased ADC percentage for low b-value combination was bigger than those for high b-value combination. Conclusion The overall value for evaluating the treatment response to radiochemotherapy for cervical cancer was higher for high b-value combination than those for low b-value combination, and the data were more stable for high b-value combination.