Solid-type adenocarcinoma on thin-section CT: quantitative parameters from dual-energy CT associated with spread through air spaces.

Background: Spread through air spaces (STAS) is a well-established factor associated with poor oncological outcomes in patients undergoing surgery for solid lung adenocarcinoma. There could potentially be a disparity in iodine uptake between patients with positive and negative airway spread of solid lung adenocarcinoma.

Purpose: To explore the associations and find correlations of iodine uptake with STAS status in patients who underwent surgery for solid lung adenocarcinoma.

Material and methods: Patients who underwent solid lung adenocarcinoma resection between January and June 2022 were included in this retrospective study. Iodine concentration and CT features were assessed using contrast-enhanced dual-energy computed tomography (DECT) scans, and these were compared with the status of STAS.

Results: Of 52 patients included, 25 (48%) were STAS-positive and 27 (52%) were STAS-negative. There were no statistically significant differences in CT features between the two groups (P > 0.05). STAS-positive was significantly associated with low arterial phase iodine concentration (ICA), normalized arterial phase iodine concentration (NICA), and venous phase iodine concentration (ICV), with a cutoff established at 1.15 mg/mL, 0.11, and 1.35 mg/mL, respectively (P < 0.05). The AUCs for ICA, NICA, and ICV in predicting STAS in solid lung adenocarcinoma were 0.82, 0.83, and 0.73, respectively. ICA and NICA were identified as independent risk factors for STAS in solid lung adenocarcinoma, with a combined AUC of 0.89.

Conclusion: This study suggests that solid lung adenocarcinoma patients with low ICA, NICA, and ICVA were associated with STAS-positive, as well as a worse survival outcomes.