Background Nondisappearing subsolid nodules requiring follow-up are often detected during lung cancer screening, but changes in their invasiveness can be overlooked owing to slow growth. We aimed to develop a method for automatic identification of invasive tumors among subsolid nodules during multiple health checkups using radiomics technology based on low-dose computed tomography (LD-CT) and examine its effectiveness.

Methods We examined patients who underwent LD-CT screening from 2014 to 2019 and had lung adenocarcinomas resected after 5-year follow-ups. They were categorized into the invasive or less-invasive group; the annual growth/change rate (Δ) of the nodule voxel histogram using three-dimensional CT (e.g., tumor volume, solid volume percentage, mean CT value, variance, kurtosis, skewness, and entropy) was assessed. A discriminant model was designed through multivariate regression analysis with internal validation to compare its efficacy with that of a volume doubling time of < 400 days.

Results The study included 47 tumors (23 invasive, 24 less invasive), with no significant difference in the initial tumor volumes. Δskewness was identified as an independent predictor of invasiveness (adjusted odds ratio, 0.021; p = 0.043), and when combined with Δvariance, it yielded high accuracy in detecting invasive lesions (88% true-positive, 80% false-positive). The detection model indicated surgery 2 years earlier than the volume doubling time, maintaining accuracy (median 3 years vs.1 year before actual surgery, p = 0.011).

Conclusion LD-CT radiomics showed promising potential in ensuring timely detection and monitoring of subsolid nodules that warrant follow-up over time.

背景 肺癌筛查过程中经常会发现需要随访的未消失的亚实性结节，但由于生长缓慢，其侵袭性的变化可能被忽视。我们的目的是开发一种利用基于低剂量计算机断层扫描（LD-CT）的放射组学技术在多次健康检查中自动识别亚实性结节中浸润性肿瘤的方法，并检验其有效性。

方法 我们检查了 2014 年至 2019 年接受 LD-CT 筛查并在 5 年随访后切除肺腺癌的患者。他们被分为侵入性组或侵入性较小组；使用三维CT（例如，肿瘤体积、实体体积百分比、平均CT值、方差、峰度、偏度和熵）评估结节体素直方图的年生长/变化率（Δ）。通过多元回归分析和内部验证设计判别模型，以将其功效与 < 400 天的体积倍增时间的功效进行比较。

结果 该研究包括 47 个肿瘤（23 个侵袭性肿瘤，24 个侵袭性较小），初始肿瘤体积没有显着差异。Δ偏度被认为是侵袭性的独立预测因子（调整后的比值比，0.021；p  = 0.043），当与Δ方差相结合时，它在检测侵袭性病变方面具有很高的准确性（88% 真阳性，80% 假阳性）。检测模型表明手术比体积倍增时间早 2 年，保持准确性（中位 3 年与实际手术前 1 年，p  = 0.011）。

结论 LD-CT 放射组学在确保及时发现和监测需要长期随访的亚实性结节方面显示出巨大的潜力。