Role of Lung Perfusion Scintigraphy in Relation to Chest Computed Tomography and Pulmonary Function in the Evaluation of Candidates for Lung Volume Reduction Surgery

Abstract

Lung perfusion scintigraphy is employed to evaluate patients with severe emphysema who are candidates for lung volume reduction surgery (LVRS). Our purpose was to investigate the role of scintigraphy in relation to chest computed tomography (CT) and lung function in this setting. Six observers blinded to clinical data retrospectively scored preoperative scintigrams of 70 patients undergoing bilateral video-assisted LVRS according to the distribution of lung perfusion as homogeneous, intermediately heterogeneous, or markedly heterogeneous. Heterogeneity of emphysema distribution was also assessed by chest CT. Dyspnea and pulmonary function were measured preoperatively and 3 mo postoperatively. In 42 patients with markedly heterogeneous, in 18 with intermediately heterogeneous, and in 10 with homogeneous perfusion, mean (+/- SE) FEV1 increased by 57 +/- 8% (p < 0.0001), 38 +/- 9% (p < 0.001), and 23 +/- 9% (p = NS) (p = NS for intergroup comparisons). In a multiple regression analysis, functional improvement after LVRS was more closely correlated with preoperative hyperinflation and the degree of emphysema heterogeneity estimated by chest CT than with the degree of perfusion heterogeneity assessed by scintigraphy. In 16 of 22 patients with homogeneous emphysema distribution in the chest CT scintigraphy revealed intermediately or markedly heterogeneous perfusion. We conclude that lung perfusion scintigraphy has a limited role in prediction of outcome, but it may help to identify target areas for resection in LVRS candidates with homogeneous CT morphology.

New 133Xe Gas Trapping Index for Quantifying Severe Emphysema Before Partial Lung Volume Reduction

“…The lack of a high correlation of the GTI with CT is likely because the GTI reflects not only parenchymal damage but also smallairway disease. The 133 Xe GTI therefore may serve better to select patients who are not candidates for LVR (27).…”

“…In addition, because the 133 Xe study was performed with the patient upright and the CT studies with the patient supine, this may have further contributed to differences in measurements between 133 Xe and CT. In future investigations, SPECT ventilation scans could be used and might provide a better correlation with CT (27). There are, however, practical limitations in performing SPECT on a patient on a 133 Xe images illustrate washin phase (frames 1-4), equilibrium phase (frames 5-10), and washout phase (frames 11-16).…”

Radiographic Evaluation of the Potential Lung Volume Reduction Surgery Candidate

“…Wang and colleagues concluded that upperlobe predominance and heterogeneity identified from perfusion scanning were ''modestly'' predictive of response to LVRS (37). Others have concluded, however, that it adds little to CT scanning in LVRS evaluation (5,38,39).…”

Lung volume reduction surgery: what can we learn from the National Emphysema Treatment Trial?: Fig. 1.—

“…A more detailed categorisation to test the role of emphysema morphology on the outcome of LVRS would have extended previous knowledge on the role of this classification [20].…”