Prognostic value of 3D mean CT attenuation in the solid component of resected part-solid lung adenocarcinomas

Preoperative prediction of recurrence in non-small cell lung cancer (NSCLC) remains limited using conventional imaging parameters such as tumor size, consolidation-to-tumor (C/T) ratio, and 2D mean computed tomography attenuation (mCT) value. This study aimed to evaluate the prognostic utility of the 3D-solid mCT value in patients with surgically resected NSCLC.

A total of 138 patients with part-solid adenocarcinomas who underwent complete resection between 2012 and 2018 were retrospectively analyzed. Preoperative CT data were processed using a 3D workstation to measure tumor volume and calculate the 3D-solid mCT value. Recurrence-free survival (RFS) was the primary outcome. Receiver operating characteristic (ROC) analysis was used to identify optimal cut-off values. Survival was analyzed using Kaplan-Meier and Cox proportional hazards models.

Patients were divided into high (≥-106.0 HU) and low (<-106.0 HU) 3D-solid mCT value groups. The high value group showed significantly worse 5-year RFS (65.8% vs. 98.4%, P<0.001). The 3D-solid mCT value had the highest predictive accuracy for recurrence [area under the curve (AUC) =0.724] compared to the 2D-mCT value (AUC =0.643, P=0.02) and C/T ratio (AUC =0.598). Multivariate analysis identified high 3D-solid mCT value (hazard ratio: 9.22, P=0.02) and lymphatic invasion (P=0.002) as independent predictors of recurrence.

The 3D-solid mCT value is a strong, independent predictor of postoperative recurrence in NSCLC and showed better predictive performance than conventional 2D imaging parameters in ROC analysis. Preoperative assessment of this value may help identify high-risk patients and support personalized postoperative management. However, further studies with formal model comparison are warranted to confirm its superiority.