Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong.
NMR Biomed. 2013 Feb;26(2):185-92. doi: 10.1002/nbm.2834. Epub 2012 Jul 16.
We compared the parameters derived from diffusion-weighted imaging (DWI) and positron emission tomography/computed tomography (PET/CT) for treatment response evaluation and response prediction in patients with gastrointestinal stromal tumor (GIST). Seven patients with histologically proven metastatic disease were enrolled. DWI and PET/CT data were collected from all patients at diagnosis and from six at follow-up. All 37 lesions were identifiable in DWI with a sensitivity of 100%. To achieve higher accuracy, we used the apparent diffusion coefficient (ADC) of liver and background noise as thresholds for the measurement of the ADCs of lesions. Significant inverse correlations were found between ADC(mean_thr) (ADC(mean) with thresholds) and SUV(mean) (mean standardized uptake value) (R(2)=0.523, p<0.001 at diagnosis, and R(2)=0.916, p<0.001 at follow-up), between ADC(mean_thr) and SUV(max) (maximum SUV) (R(2)=0.529, p<0.001 at diagnosis, and R(2)=0.761, p<0.001 at follow-up), between ΔADC(mean_thr) (percentage change in ADC(mean_thr) ) and ΔSUV(mean) (percentage change in SUV(mean) ) (R(2)=0.384, p<0.001), and between ΔADC(mean_thr) and ΔSUV(max) (percentage change in SUV(max) ) (R(2)=0.500, p<0.001). In lesion-based analysis, pre-treatment ADC(mean_thr) outperformed SUV(mean) and SUV(max) in treatment response prediction, with an area under the receiver operating characteristic curve of 0.706. These results show that DWI can provide a quantitative assessment comparable with PET/CT in GIST lesion characterization, treatment response evaluation and response prediction.
我们比较了弥散加权成像（DWI）和正电子发射断层扫描/计算机断层扫描（PET/CT）在胃肠道间质瘤（GIST）患者治疗反应评估和反应预测中的参数。共纳入 7 例经组织学证实为转移性疾病的患者。所有患者在诊断时和 6 例在随访时均采集 DWI 和 PET/CT 数据。DWI 可在 100%的患者中识别出所有 37 个病灶。为了获得更高的准确性，我们使用肝脏表观扩散系数（ADC）和背景噪声作为病灶 ADC 测量的阈值。在诊断时，ADC（mean_thr）（ADC（mean）与阈值）与 SUV（mean）（平均标准化摄取值）之间存在显著的负相关（R²=0.523，p<0.001），在随访时，ADC（mean_thr）与 SUV（max）（最大 SUV）之间存在显著的负相关（R²=0.916，p<0.001）（R²=0.529，p<0.001），在随访时，ADC（mean_thr）与 SUV（max）（最大 SUV）之间存在显著的负相关（R²=0.761，p<0.001）（R²=0.384，p<0.001），ΔADC（mean_thr）（ADC（mean_thr）的百分比变化）与ΔSUV（mean）（SUV（mean）的百分比变化）之间存在显著的负相关（R²=0.384，p<0.001），ΔADC（mean_thr）与ΔSUV（max）（SUV（max）的百分比变化）之间存在显著的负相关（R²=0.500，p<0.001）。在基于病灶的分析中，治疗前 ADC（mean_thr）在预测治疗反应方面优于 SUV（mean）和 SUV（max），受试者工作特征曲线下面积为 0.706。这些结果表明，DWI 可以提供与 GIST 病变特征、治疗反应评估和反应预测中的 PET/CT 相当的定量评估。
