Assessment of Pulmonary Tuberculosis Treatment Response Using Serial Chest Computed Tomography

Abstract

Background: Pulmonary tuberculosis (PTB) remains a major global health challenge despite the availability of effective antimicrobial therapy. Accurate assessment of treatment response is essential for ensuring cure, detecting treatment failure, and preventing drug resistance. While sputum-based microbiological tests remain the reference standard, imaging plays a critical complementary role, particularly in patients with negative sputum results or persistent symptoms. Chest computed tomography (CT) offers superior sensitivity compared to chest radiography in detecting parenchymal and airway abnormalities associated with PTB. This article reviews the role of serial chest CT in evaluating treatment response in pulmonary tuberculosis, describing characteristic imaging findings, temporal changes during therapy, quantitative and qualitative assessment methods, clinical utility, and limitations. Pulmonary tuberculosis (TB) remains a major global health challenge, and despite the availability of standardized treatment regimens, timely assessment of therapeutic response continues to be a clinical priority. Conventional sputum-based methods and chest radiography have limitations in sensitivity and temporal resolution, particularly in detecting subtle parenchymal changes. Chest computed tomography (CT), with its superior ability to characterize lung architecture, offers potential advantages in evaluating disease trajectory and guiding clinical decision-making. Aim: To evaluate treatment response in patients with pulmonary tuberculosis using serial chest CT scans and determine the characteristic imaging changes associated with successful therapy.

Material and Methods: This retrospective observational study included patients with microbiologically confirmed pulmonary TB who underwent baseline and follow-up chest CT imaging during the course of standard anti-tubercular therapy. CT scans were reviewed independently by two experienced thoracic radiologists. Key imaging parameters assessed included the presence and extent of cavitation, nodules, consolidations, tree-in-bud opacities, lymphadenopathy, and pleural involvement. Changes in these features were compared across serial examinations to determine patterns of radiological improvement or persistence. Clinical and microbiological treatment response indicators were correlated with CT findings to strengthen interpretative validity.

Results: Serial CT evaluation demonstrated consistent radiologic trends in patients responding to treatment. The most notable improvements included reduction in cavity size, decreased nodular burden, resolution of consolidations, and marked regression of tree-in-bud opacities. Lymph node enlargement and pleural abnormalities also showed significant interval improvement in many cases. In contrast, a subset of patients with persistent or worsening CT abnormalities exhibited delayed microbiological conversion or clinical non-response. CT findings provided earlier detection of treatment failure compared to conventional radiography and often preceded sputum conversion in several clinically improving patients.

Conclusion: Serial chest CT is a valuable adjunct in monitoring therapeutic response in pulmonary tuberculosis, offering enhanced sensitivity in detecting parenchymal and airway changes. Its use can support earlier recognition of inadequate treatment response and help optimize individualized patient management.