Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York; Department of Radiology, Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, People's Republic of China.
Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York.
J Thorac Oncol. 2017 Apr;12(4):657-662. doi: 10.1016/j.jtho.2016.12.010. Epub 2016 Dec 19.
The aim of this study was to understand the effect of rounding nodule size measurements on the frequency of positive results in the setting of lung cancer screening.
Four methods for determining nodule size were compared, including rounding each individual length and width measurement and also rounding the overall average. These were applied to the International Early Lung Cancer Action Program database, in which we determined the frequency of a positive result by using standard size thresholds of 6.0 mm on baseline screening and 3.0 mm on repeat scanning. We also explored how rounding influences the ability to measure growth according to a predefined cutoff value of 1.5 mm as required in the Lung Computed Tomography Screening Reporting and Data System (Lung-RADS) (version 1.0).
Each method for rounding increased the frequency of positive results compared with that with no rounding. The largest increases-28.9% and 22.3% for the baseline and repeat round, respectively-occurred when rounding was used for both the individual length and width measurements and again for the final diameter. If the 1.5-mm increase in size were used for determining growth, a 4-mm nodule would need to have a volume doubling time of 130.6 days or less to demonstrate growth in 6 months (Lung-RADS category 3) whereas a 6-mm nodule would need volume doubling time of 93.2 days to demonstrate growth in 3 months (Lung-RADS category 4A). In addition, rounding can have the effect of having nodules that appear to not be growing meet the criteria for growth and vice versa.
Rounding influences the frequency of positive results and growth assessment, substantially decreasing the efficiency of screening.
本研究旨在了解在肺癌筛查中测量结节大小的方法对阳性结果频率的影响。
比较了 4 种确定结节大小的方法，包括分别对每个长度和宽度测量值进行四舍五入以及对总体平均值进行四舍五入。这些方法应用于国际早期肺癌行动计划数据库，我们根据 6.0mm 的基线筛查标准和 3.0mm 的重复扫描标准来确定阳性结果的频率。我们还探讨了四舍五入如何影响根据 Lung Computed Tomography Screening Reporting and Data System (Lung-RADS) (版本 1.0) 中规定的 1.5mm 的预设增长值来测量增长的能力。
与不四舍五入相比，每种四舍五入方法都增加了阳性结果的频率。基线和重复四舍五入的最大增幅分别为 28.9%和 22.3%，分别发生在分别对个体长度和宽度测量值以及最终直径进行四舍五入时。如果使用 1.5mm 的大小增加来确定增长，则需要 4mm 的结节体积倍增时间为 130.6 天或更短，才能在 6 个月内（Lung-RADS 类别 3）显示出增长，而 6mm 的结节则需要体积倍增时间为 93.2 天，才能在 3 个月内（Lung-RADS 类别 4A）显示出增长。此外，四舍五入会使原本看起来没有增长的结节符合增长标准，反之亦然。
四舍五入会影响阳性结果和增长评估的频率，大大降低了筛查的效率。
