[The reliability of scintigraphic criteria of the lungs concerning the estimation of mediastinal involvement in case of bronchial carcinoma (prospective study) (author's transl)].

The goal of this prospective study is to determine the reliability of the scintigraphic diagnosis of mediastinal involvement in patients with bronchial carcinoma, as well as to establish the value of each individual scintigraphic criterion. Ninety-four patients, all of whom were hospitalized because of suspicion of bronchial carcinoma were examined using 133-Xenon i.v., 133-Xenon gas inhalation, and 99m-Tc-MAA i.v. (macroaggregated albumin or microspheres of human albumin). The suspicion was confirmed in 77 patients. -The most reliable scintigraphic criteria are: 1. a localized delayed appearance of the activity in the afflicted lung area during the first 20 sec of the 133-Xenon i.v. series, and 2. the presence of a "dead-space" ventilation. Activity remaining in the area of the subclavian vein or the superior vena cava up to 10 min after the injection of 133-Xenon i.v. must be very carefully interpreted. Sixty-five patients underwent both mediastinoscopy and scintigraphy: in 44 patients (= 68%) the findings in both examinations were the same. Compared to the final diagnosis (mediastinoscopy, operation) there were 20 (= 30%) false negative but only one (= 2%) false positive scintigraphic diagnoses made. -When the scintigraphic criteria of hilar or mediastinal involvement are fulfilled, then the patient is practically certain to be no longer radically operable. This assertion is valid even when the mediastinoscopy is normal.