Radiographic Severity and Treatment Optimization in MAC Pulmonary Disease

Background We developed a chest radiography (CXR) scoring system using a deep neural network to quantify the severity of Mycobacterium avium complex pulmonary disease (MAC-PD). This study aimed to stratify disease extent using CXR scores and propose treatment strategy accordingly. Methods We analyzed chest radiographs obtained at treatment initiation in patients who began therapy for MAC-PD at Seoul National University Hospital between January 1, 2011, and August 31, 2024. Patients were classified into mild or extensive disease groups based on a CXR score cutoff of 4.0. The impact of macrolide/ethambutol-based initial treatment regimens, alternative intensified regimens (including inhaled amikacin or clofazimine), and intensified regimens (including intravenous amikacin) on culture conversion was assessed using Cox proportional hazards models. Results The study comprised 541 patients (299 and 242 with mild and extensive disease types, respectively). Alternative intensified regimens were used in 103 patients (19.0%), and intensified regimens were used in 25 patients (4.6%). Culture conversion was achieved in 450 patients (83.2%), with no significant differences between the mild (81.6%) and extensive (85.1%) groups (p=0.277). In mild disease, neither alternative intensified regimens (adjusted hazard ratio [aHR], 0.84; 95% confidence interval [CI], 0.60–1.19) nor intensified regimens (aHR, 0.99; 95% CI, 0.53–1.89) were associated with improved culture conversion. In contrast, in extensive disease, use of intensified regimens (aHR, 1.90; 95% CI, 1.12–3.22) was associated with a higher likelihood of culture conversion Conclusion CXR score-based disease stratification may guide individualized treatment strategy in patients with MAC-PD.