Perfusion lung scintigraphy for the prediction of postlobectomy residual pulmonary function

Study objectives: Scintigraphic prediction of the residual pulmonary function following a lobectomy is not widely employed; its accuracy is poorly known. This study aims at determining the accuracy and the clinical value of the scintigraphic prediction of postlobectomy residual function. Patients and interventions: In this study, 41 patients with bronchial carcinoma underwent a perfusion lung scintigraphy before lobectomy; the functional contribution of each single lobe was computed by an indirect method proposed by Wernly et al; the results of the scintigraphic prediction were compared with those of the pulmonary function tests per formed 1 month after Surgery. Measurements and results: The linear regression analyses of predicted and observed values of FVC and FEV1 showed significant correlations (R-2 = 0.607 and 0.749, respectively); however, an evident scatter of data was obtained, as quantified by the values of imprecision (20.70% and 18.11%, respectively) and global inaccuracy (25.50% and 22.90%, respectively). The estimates of both FCV and FEV1 were significantly better in right lung lobectomies than in left lung lobectomies (mean imprecision and global inaccuracy: 15.43% and 14.94% for the light lung, and 27.27% and 29.00% for the left lung). Conclusions: The scintigraphic prediction of postlobectomy residual function is easily implemented by the method herein employed; it has a greater margin of uncertainty than that of pneumonectomy, especially for left lobectomies; however, the use of some safety thresholds for predicted values of FEV1 (1.2 L for upper lobectomies and 1 L for lower lobectomies) guarantees a safe clinical use of the test.