Cluster analysis as a function of the number of clusters.

Results from cluster analysis (cluster centres and voxel counts) as a function of k (number of clusters), and percentage reduction after induction chemotherapy (IC) for the combination of primary tumours and lymph nodes. In total, 2179 voxels were considered in the analysis, from which 1435 were measured at baseline and 744 post-IC, with a global percentage reduction of 48%. Asterisks indicate significant two-tailed p-values (p < 0.05) from the Wilcoxon signed-ranks test, comparing the number of voxels pre and post-treatment. IAUGC60 (initial area under the gadolinium curve integrated over 60 s) is expressed in units of mmol·s, ADC (apparent diffusion coefficient) in units of ×10−3 mm2/s.
Cluster analysis as a function of the number of clusters.

本数据集包含以k（簇数量）为自变量的聚类分析（cluster analysis）结果（含簇中心与体素数），以及联合原发肿瘤与淋巴结病灶经诱导化疗（induction chemotherapy, IC）后的体素减少率。本次分析共纳入2179个体素，其中1435个为基线扫描时测得，744个为诱导化疗后扫描测得，整体体素减少百分比达48%。图/表中的星号代表采用Wilcoxon符号秩检验（Wilcoxon signed-ranks test）比较治疗前后体素数所得的具有统计学意义的双侧p值（p < 0.05）。IAUGC60（initial area under the gadolinium curve integrated over 60 s，初始钆曲线60秒积分面积）的单位为mmol·s，ADC（apparent diffusion coefficient，表观扩散系数）的单位为×10⁻³ mm²/s。以簇数量为变量的聚类分析结果。