CT Imaging Assessment of Response to Treatment in Chronic Pulmonary Aspergillosis

Abstract

Background: Long-term antifungal therapy is usually the only treatment option for chronic pulmonary aspergillosis. However, response rates are difficult to compare because the reported clinical, mycologic, or radiologic criteria are not standardized. Objective parameters are therefore needed. To define the most relevant CT imaging variables in assessment of response to treatment, we investigated changes over time in CT imaging variables.

Methods: Changes in CT imaging variables were assessed by systematic analysis of the CT scan findings of 36 patients at diagnosis and 6 months after initiation of treatment. The relevant radiologic variables were determined by selecting those showing significant changes over time. Two experienced thoracic radiologists, blinded for clinical and serologic response, independently performed CT scan analyses. Interreader agreement and concordance between radiologic and clinical response were evaluated.

Results: Of the 36 patients, seven experienced clinical deterioration while undergoing therapy. Significantly evolving radiologic variables included cavity and pleural wall thickening (P < .05), which were associated with clinical improvement. There was a strong association between fungus ball disappearance and cavity/pleural wall thickening reduction and clinical improvement (P = .04). There was poor agreement between size changes of cavities or nodules, and clinical evolution (Cohen's κ, -0.13 to -0.24).

Conclusions: Variations in cavity and pleural wall thickness may be the most relevant CT imaging variables for assessing response to treatment. Loss of fungus ball is strongly associated with clinical and radiologic improvement, but cavity size changes are unrelated to chronic pulmonary aspergillosis evolution. All these CT imaging variables may be applied in future clinical trials to assess treatment outcome.

Keywords: CT; chronic pulmonary aspergillosis; radiologic response; treatment outcome.