PERFUSION LUNG SCINTIGRAPHY FOR THE PREDICTION OF POSTLOBECTOMY RESIDUAL PULMONARY-FUNCTION

Study objectives: Scintigraphic prediction of the residual pulmonary f unction following a lobectomy is not widely employed; its accuracy is poorly known. This study aims at determining the accuracy and the clin ical value of the scintigraphic prediction of postlobectomy residual f unction. Patients and interventions: In this study, 41 patients with b ronchial carcinoma underwent a perfusion lung scintigraphy before lobe ctomy; the functional contribution of each single lobe was computed by an indirect method proposed by Wernly et al; the results of the scint igraphic 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 an d FEV1 showed significant correlations (R-2 = 0.607 and 0.749, respect ively); however, an evident scatter of data was obtained, as quantifie d by the values of imprecision (20.70% and 18.11%, respectively) and g lobal inaccuracy (25.50% and 22.90%, respectively). The estimates of b oth FCV and FEV1 were significantly better in right lung lobectomies t han 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 le ft lung). Conclusions: The scintigraphic prediction of postlobectomy r esidual function is easily implemented by the method herein employed; it has a greater margin of uncertainty than that of pneumonectomy, esp ecially for left lobectomies; however, the use of some safety threshol ds for predicted values of FEV1 (1.2 L for upper lobectomies and 1 L f or lower lobectomies) guarantees a safe clinical use of the test.