Serial CT changes in different components of lung cancer associated with cystic airspace in patients treated with neoadjuvant chemotherapy

The aim of this study was to observe changes in different components (solid, cystic airspace, or entire tumor) in lung cancer associated with cystic airspace following treatment with neoadjuvant chemotherapy (NC), using computerized tomography (CT). We analyzed serial (baseline, first-time follow-up, and last-time follow-up) clinical data and CT imaging in six patients treated with NC. The diameters, areas, and volumes of different tumor components (solid, cystic airspace, and entire tumor) were measured. Delta (Δ) was used to represent changes in these parameters between two examinations: Δ1(%) represents the change from baseline to first follow-up after NC, and Δ2(%) represents the change from baseline to last follow-up after NC. We used the intra-group correlation coefficient (ICC) to test for consistency between parameters as measured by two radiologists. The diameter of solid components in all lesions showed a trend of continuous reduction compared with baseline (Δ1 ranged from − 8.3 to − 46.0%, Δ2 from − 30.8 to − 69.2%). For cystic airspace and entire tumors, different lesions showed different trends over the course of treatment. For diameter, area, and volume, Δ1 of changes in the solid component ranged from − 8.3 to − 46.9%, − 19.4 to − 70.8%, and − 19.1 to − 94.7%, respectively; Δ2 ranged from − 30.8 to − 69.2%, − 50.8 to − 92.1%, and − 32.7 to − 99.8% in diameter, area, and volume, respectively. Results were inconsistent between different components of lung cancer associated with cystic airspace that was treated with NC, but the diameter, area, and volume of solid components were continuously reduced during treatment. Furthermore, area and volume measurements showed more-significant variation than diameter measurements.