Dynamic chest radiography in post-lobectomy recovery: a novel approach to evaluating pulmonary function and thoracic structures in patients with primary lung cancer.

Background: Lobectomy for lung cancer leads to changes in thoracic structures and reduced pulmonary function, but real-time evaluation of compensatory mechanisms has been challenging. This study employed dynamic chest radiography to examine post-lobectomy changes in the projected lung area and excursion of diaphragm, as evaluated by sequential chest radiography, and determine their correlation with pulmonary function recovery.

Methods: This single-center and cross-sectional study was conducted at the Shiga University of Medical Science Hospital and included 65 patients who underwent lobectomy between May 2018 and December 2020. Dynamic chest radiography was performed preoperatively and at 1, 3, 6, and 12 months postoperatively alongside standard pulmonary function tests. We evaluated the postoperative trends in pulmonary function, projected lung area, and excursion of diaphragm. The results were analyzed using the Mann-Whitney U test and Fisher's exact test. Additionally, correlations between changes in the pulmonary function and dynamic chest radiography (DCR) parameters were assessed using Spearman's rank correlation coefficients. The utility of DCR in predicting postoperative pulmonary function recovery was further examined using receiver operating characteristic (ROC) curve analysis.

Results: Significant correlations were observed between the maximum projected lung area and pulmonary function recovery, particularly in upper lobectomy cases (correlation with vital capacity at 1 month postoperatively: r=0.72, P<0.01). This correlation was observed consistently across various surgical procedures, which suggests that early postoperative projected lung area measurements can predict pulmonary function recovery at 12 months. Excursion of diaphragm, especially in upper lobectomy cases, also showed a positive correlation with pulmonary function recovery (correlation with vital capacity at 1 month postoperatively: r=0.55, P<0.01). Receiver operating characteristic curve analysis validated the predictive capability of early postoperative projected lung area for long-term pulmonary function recovery with area under the curve of 0.815 [95% confidence interval (CI): 0.636-0.994] for upper lobectomy and 0.798 (95% CI: 0.564-0.982) for lower lobectomy groups.

Conclusions: Dynamic chest radiography, which assessed the projected lung area and excursion of diaphragm, emerged as a promising non-invasive tool for monitoring post-lobectomy recovery and guiding rehabilitation efforts. These findings indicate its potential as an early predictor of pulmonary recovery, advocating for its integration into the perioperative care of patients with lung cancer. Future research should expand patient cohorts and refine predictive models using preoperative dynamic chest radiography to enhance post-lobectomy outcomes.