Measurement of lung function deterioration in COPD by V/P SPECT

Measurement of progression of both airway obstruction and parenchymal damage affecting ventilation and perfusion of the lungs in COPD is important for management of patients and for predicting their prognosis. Thirty Chinese patients with a stable COPD (GOLD criteria) were enrolled in an international study and followed-up for 12 months. Age ranged 47-83 years, smoking pack years 0-104, and post-bronchodilatation FEV1 23-74 % predicted. Ventilation and perfusion tomography (V/P SPECT) was performed and interpreted according to European Nuclear Medicine guidelines (Bajc, M. et al. Ann Nucl Med 2015; 29: 91). Obstructive bronchitis was classified by penetration of Technegas™ to periphery and quantified to estimate % of missing lung function in relation to total lung volume. Emphysema was defined as area of matched or reversed mismatched V/P defects and the extent of emphysema was assessed as % of the estimated total lung volume (E%). Total preserved lung function (TPLF%) falling due to reduction of ventilation and/or emphysema was calculated as percentage of total lung volume. Pulmonary function was followed by FEV1 and FVC. Patients had on the average 0.6 (range 0-2) COPD exacerbations and 2 patients died for cardiovascular events during 12 months. E% increased (10+/-15%, range 0-50%, p<0.05) and was related to diminishing TPLF% (-10+/-11%, range -30%-5%). Post-bronchodilatation FVC decreased by -16+/-14 % (range -42-12%). Post-bronchodilatation FEV1 (1+/-9 %, range -19-25%) or FEV% (5+/-10 %, range -11-30%) did not change significantly. Results suggest that in COPD the total lung function deterioration can be measured and patients who have a rapid destruction of lung parenchyma can be picked up by V/P SPECT.