Quantitative assessment of ventilation-perfusion relationships with gallium-68 positron emission tomography/computed tomography imaging in lung cancer patients

Pulmonary functional imaging has demonstrated potential to improve thoracic radiotherapy. The purpose of this study was twofold: 1) to quantify ventilation/perfusion relationships in lung cancer patients using a new functional imaging approach, gallium-68 ((68)Ga)-positron emission tomography/computed tomography (PET/CT); and 2) to compare ventilation/perfusion matching with diffusing capacity of the lung for carbon monoxide (D(LCO)). Voxel-wise correlations between ventilation and perfusion varied widely among 19 patients (range: 0.26–0.88). (68)Ga-PET/CT-measured percent gas exchanging lung volume was moderately correlated with D(LCO) (≤0.59). Our findings suggested that (68)Ga-PET/CT ventilation/perfusion imaging provided complementary information and a reasonable surrogate for gas exchange in lung cancer patients.