Morgan Veronica A, Parker Christopher, MacDonald Alison, Thomas Karen, deSouza Nandita M
1 Cancer Research UK Cancer Imaging Centre, MRI Unit, Royal Marsden Hospital, Downs Rd, Sutton, Surrey SM2 5PT, UK.
2 Academic Urology Unit, Royal Marsden Hospital NHS Foundation Trust and Institute of Cancer Research, Sutton, Surrey, UK.
AJR Am J Roentgenol. 2017 Sep;209(3):620-628. doi: 10.2214/AJR.17.17790. Epub 2017 Jun 13.
The purpose of this study was to measure longitudinal change in tumor volume of the dominant intraprostatic lesion and determine whether baseline apparent diffusion coefficient (ADC) and change in ADC are indicative of tumor growth in patients with prostate cancer undergoing active surveillance.
The study group included 151 men (mean age, 68.1 ± 7.4 [SD] years; range, 50-83 years) undergoing active surveillance with 3D whole prostate, zonal, and tumor volumetric findings documented at endorectal MRI examinations performed at two time points (median interval, 1.9 years). Tumor (location confirmed at transrectal ultrasound or template biopsy) ADC was measured on the slice with the largest lesion. Twenty randomly selected patients had the measurements repeated by the same observer after a greater than 4-month interval, and the limits of agreement of measurements were calculated. Tumor volume increases greater than the upper limit of agreement were designated measurable growth, and their baseline ADCs and change in ADC were compared with those of tumors without measurable growth (independent-samples t test).
Fifty-two (34.4%) tumors increased measurably in volume. Baseline ADC and tumor volume were negatively correlated (r = -0.42, p = 0.001). Baseline ADC values did not differ between those with and those without measurable growth (p = 0.06), but change in ADC was significantly different (-6.8% ± 12.3% for those with measurable growth vs 0.23% ± 10.1% for those without, p = 0.0005). Percentage change in tumor volume and percentage change in ADC were negatively correlated (r = -0.31, p = 0.0001). A 5.8% reduction in ADC indicated a measurable increase in tumor volume with 54.9% sensitivity and 77.0% specificity (AUC, 0.67).
Tumor volume increased measurably in 34.4% of men after 2 years of active surveillance. Change in ADC may be used to identify tumors with measurable growth.
本研究旨在测量前列腺内主要病灶肿瘤体积的纵向变化，并确定基线表观扩散系数（ADC）及ADC变化是否可指示接受主动监测的前列腺癌患者的肿瘤生长情况。
研究组包括151名男性（平均年龄68.1±7.4[标准差]岁；范围50 - 83岁），他们接受了主动监测，在两个时间点（中位间隔时间为1.9年）进行的直肠内MRI检查记录了三维全前列腺、分区及肿瘤体积数据。在最大病灶所在层面测量肿瘤（经直肠超声或模板活检确认位置）的ADC。20名随机选择的患者在间隔超过4个月后由同一名观察者重复测量，并计算测量的一致性界限。肿瘤体积增加超过一致性界限上限被定义为可测量生长，将其基线ADC及ADC变化与无可测量生长的肿瘤进行比较（独立样本t检验）。
52个（34.4%）肿瘤体积出现可测量的增加。基线ADC与肿瘤体积呈负相关（r = -0.42，p = 0.001）。有可测量生长与无可测量生长的肿瘤的基线ADC值无差异（p = 0.06），但ADC变化有显著差异（可测量生长的肿瘤为-6.8%±12.3%，无可测量生长的肿瘤为0.23%±10.1%，p = 0.0005）。肿瘤体积百分比变化与ADC百分比变化呈负相关（r = -0.31，p = 0.0001）。ADC降低5.8%表明肿瘤体积有可测量增加，敏感性为54.9%，特异性为77.0%（曲线下面积为0.67）。
经过2年的主动监测，34.4%的男性患者肿瘤体积出现可测量的增加。ADC变化可用于识别有可测量生长的肿瘤。
