The Value of V/Q SPECT/CT Lobar Quantitation for Pre-Treatment Assessment of Lung Malignancy

This article evaluates a novel single-photon emission computed tomography/computed tomography (VQ SPECT/CT)-derived Ventilation Perfusion Capacity Differential Index (VQCDI) for predicting post-treatment lung function in early-stage lung cancer. VQCDI combines lobar ventilation, perfusion, and volume to estimate each lobe’s functional contribution and was applied to patients undergoing lobectomy, sub-lobar resection, or stereotactic ablative body radiotherapy (SABR). In 53 prospectively enrolled patients, VQCDI-predicted six-month forced expiratory volume in one second (FEV1) in surgical cases showed a very strong correlation and agreement with measured values and outperformed CT volumetry alone, including in smokers and those with emphysema. Diffusing capacity of the lungs for carbon monoxide (DLCO) and hemoglobin-corrected DLCO (DLCOc) predictions also correlated well but with wider limits of agreement. VQCDI appears feasible and physiologically relevant, warranting multicenter validation.