Serial Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (18FDG-PET-CT) in Assessing Treatment Response in Chronic Pulmonary Aspergillosis

Abstract

Abstract Background The role of 2-deoxy-2-18(F) fluoro-D-glucose (FDG) positron emission tomography (PET)-computed tomography (CT) in assessing treatment response in chronic pulmonary aspergillosis (CPA) remains to be determined. The study objective was to compare FDG-PET/CT parameters in persons with CPA achieving treatment success or failure after 6 months of oral itraconazole. Methods We performed PET-CT at baseline and after 6 months of oral itraconazole therapy. FDG uptake similar to the background uptake or ≥13 units decline in Z-score was considered a complete metabolic response (CMR). A >25%, >30%, and > 45% decline in standardised uptake value (SUVmax), SUVpeak, and total glycolytic activity (TLG) was labelled as a partial metabolic response (PMR). A >30%, >30%, or >75% increase in the SUVmax, SUVpeak, and TLG represented progressive metabolic disease. Results We included 94 persons with CPA (63 male) with a mean age of 46.2 years. A follow-up PET-CT was performed on 77 participants. We recorded treatment success and failure in 43 and 34 patients. CMR was seen in 18.6% of those with treatment success and none with treatment failure. A higher proportion of patients with treatment success achieved PMR; 19% of the patients with treatment success had progressive metabolic disease. Conclusions Most PET-CT parameters improved with treatment; however, PET-CT misclassified one-fifth of the participants.