Jennings S Gregory, Winer-Muram Helen T, Tann Mark, Ying Jun, Dowdeswell Ian
Department of Radiology, Indiana University School of Medicine, 950 W Walnut St, Room E124, Indianapolis, IN 46202, USA.
Radiology. 2006 Nov;241(2):554-63. doi: 10.1148/radiol.2412051185. Epub 2006 Sep 27.
To retrospectively determine the distribution of stage I lung cancer growth rates with serial volumetric computed tomographic (CT) measurements.
This study was institutional review board approved and HIPAA compliant. The informed consent requirement was waived. Patients (n = 149) with stage I lung cancer who underwent two pretreatment CT examinations 25 or more days apart were identified. At the first and last examinations, tumor perimeters were manually inscribed by using software tools and the cross-sectional area was calculated. To calculate tumor volume, the summed areas were multiplied by the section increment and a formula was applied to reduce partial volume effects. Doubling time (DT) was calculated by using the volume and interscanning interval. The percentages of tumors that would surpass volume increase thresholds of 5%-25% for detectable growth at different time intervals were calculated. Age at diagnosis was compared with the reciprocal of DT, time interval between CT examinations, and initial tumor volume by using Pearson correlation. P < .05 denoted statistical significance.
Lung cancer was stage IA in 99 patients and stage IB in 50. Median patient age was 72 years, and median interscanning interval was 130 days. Median tumor volumes were 3000 and 6213 mm3 at the first and last examinations, respectively. Median DT was 207 days; 21 tumors did not increase in volume between examinations. The interscanning interval required for 90% of growing tumors to surpass the growth threshold ranged from 8 weeks (5% threshold) to 37 weeks (25% threshold). Fifty-three percent of growing tumors would surpass the 25% threshold at 8 weeks, and 95% would surpass it at 1 year. Age at diagnosis was negatively correlated with growth rate (P = .047); there was no correlation between growth rate and either age at diagnosis or interscanning interval.
At serial volumetric CT measurements, there was wide variability in growth rates. Some biopsy-proved cancers decreased in volume between examinations.
通过系列容积计算机断层扫描（CT）测量，回顾性确定Ⅰ期肺癌的生长速率分布情况。
本研究经机构审查委员会批准且符合健康保险流通与责任法案（HIPAA）规定。豁免了知情同意要求。确定了149例接受两次间隔25天或更长时间的治疗前CT检查的Ⅰ期肺癌患者。在首次和末次检查时，使用软件工具手动勾勒肿瘤边界并计算横截面积。为计算肿瘤体积，将各层面面积总和乘以层面间距，并应用一个公式以减少部分容积效应。通过使用体积和扫描间隔时间计算倍增时间（DT）。计算了在不同时间间隔内体积增加超过5%-25%的可检测生长阈值的肿瘤百分比。使用Pearson相关性分析比较诊断时年龄与DT的倒数、CT检查间隔时间以及初始肿瘤体积。P < 0.05表示具有统计学意义。
99例患者为ⅠA期肺癌，50例为ⅠB期。患者中位年龄为72岁，中位扫描间隔时间为130天。首次和末次检查时肿瘤中位体积分别为3000和6213 mm³。中位DT为207天；21个肿瘤在两次检查之间体积未增加。90%的生长肿瘤超过生长阈值所需的扫描间隔时间范围为8周（5%阈值）至37周（25%阈值）。53%的生长肿瘤在8周时会超过25%的阈值，95%在1年时会超过该阈值。诊断时年龄与生长速率呈负相关（P = 0.047）；生长速率与诊断时年龄或扫描间隔时间均无相关性。
在系列容积CT测量中，生长速率存在很大差异。一些经活检证实的癌症在两次检查之间体积减小。
