Radiological factors associated with the recurrence of <i>Mycobacterium avium complex</i> pulmonary disease: a multicentre retrospective cohort study

pulmonary disease (MAC-PD) frequently recurs after treatment but predictors of recurrence remain unclear. We retrospectively analysed patients with successfully treated MAC-PD from two tertiary centres. Chest CT findings-including bronchiectasis, cellular bronchiolitis, cavity, nodule and consolidation scores-were assessed before and after treatment. Multivariable competing risk regression analyses were performed to identify factors associated with recurrence. Among 538 patients, 216 (40.1%) experienced recurrence. A higher post-treatment cellular bronchiolitis score was independently associated with recurrence (adjusted subdistribution HR 1.64, 95% CI 1.46 to 1.84; p<0.001). A score ≥3 was associated with increased recurrence risk in both nodular bronchiectatic and fibrocavitary phenotypes. Residual cellular bronchiolitis on post-treatment CT demonstrated the strongest predictive performance and may serve as a radiological marker of recurrence risk.