CT Predictors of Angiolymphatic Invasion in Non–Small Cell Lung Cancer 30 mm or Smaller

Background Angiolymphatic invasion (ALI) is an important prognostic indicator in non-small cell lung cancer (NSCLC). However, few studies focus on radiologic features for predicting ALI in patients with early-stage NSCLCs 30 mm or smaller. Purpose To identify radiologic features for predicting ALI in NSCLCs 30 mm or smaller in maximum diameter. Materials and Methods This study was a secondary review of pathologic and CT findings from an integrated health care system between January 2016 and November 2023 for participants in the prospective study Initiative for Early Lung Cancer Research on Treatment, or IELCART. Preoperative diagnostic radiologic features possibly related to ALI, volume doubling time (VDT), and PET maximum standardized uptake value were evaluated. Multivariable logistic regression analysis, adjusted for sex, age, nodule size, and smoking status, was used to determine predictors of ALI. Model performance was analyzed with the area under the receiver operating characteristic curve (AUC). Results Of 778 resected NSCLCs 30 mm or smaller (median patient age, 69 years [IQR, 63-76 years]; 458 female patients), 715 (92%) were solid, 41 (5%) were part-solid, and 22 (3%) were nonsolid. ALI was documented in 271 (35%) resected NSCLCs, all in solid NSCLCs, representing 37.9% (95% CI: 34.4, 41.5) of solid NSCLCs. None of the 63 subsolid NSCLCs had ALI (0% [95% CI: 0, 5.75]). For the 715 solid NSCLCs (median patient age, 69 years [IQR, 63-76 years]; 420 female patients), multivariable logistic regression analysis showed that lollipop sign (odds ratio [OR] = 4.12 [95% CI: 2.82, 6.04]; P < .001) and spiculation (OR = 2.05 [95% CI: 1.42, 2.97]; P < .001) were independent predictors of ALI (AUC = 0.77 [95% CI: 0.73, 0.80]). Considering only the 474 patients in whom VDT could be calculated based on CT scans, VDT was also an independent predictor for ALI (OR = 0.96 [95% CI: 0.94, 0.98]; P < .001). Incorporating VDT into the model improved ALI prediction (AUC = 0.82 [95% CI: 0.77, 0.86]; P < .001). Conclusion For patients with NSCLCs 30 mm or smaller, ALI was present in 37.9% of solid NSCLCs and none of the 63 subsolid NSCLCs. Among solid NSCLCs, lollipop sign, spiculation, and VDT were independent radiologic predictors of ALI. © RSNA, 2025 Supplemental material is available for this article. See also the editorial by Czum in this issue.