18F-Fluorodeoxyglucose positron emission tomography/computed tomography for assessing treatment response of nontuberculous mycobacterial pulmonary disease

<bold>Background:</bold> This study aimed to investigate the role of ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in treatment response assessment of nontuberculous mycobacterial pulmonary disease (NTM-PD). <bold>Methods:</bold> We evaluated 26 patients with NTM-PD who underwent NTM-PD treatment and serial ¹⁸F-FDG PET/CT at baseline and 6 and 12 months after treatment. On PET images, the highest lung maximum standardized uptake value (SUV_max), mean of average SUV (SUV_avg), total metabolic lung volume (TMLV), and total lung glycolysis (TLG) were measured. <bold>Results:</bold> During a median treatment duration of 21.7 months (interquartile range, 15.6-32.3), SUV_max obtained at the start of treatment significantly decreased 6 and 12 months after treatment (6.4 vs. 4.3 vs. 3.9, <italic>P</italic> = 0.004). Culture conversion and cure were achieved in 16 patients (62%) and in 14 patients (54%), respectively. Among PET parameters, SUV_max after 12 months of treatment was significantly lower in patients with culture conversion than in those without culture conversion (2.9 vs. 5.2, <italic>P</italic> = 0.031). However, there was no difference in PET parameters between patients with and without cure. <bold>Conclusions:</bold> ¹⁸F-FDG PET/CT lung parameters were associated with treatment outcomes in patients with NTM-PD. ¹⁸F-FDG PET/CT could help to predict the prognosis of NTM-PD.