67Ga scanning for assessment of disease activity and therapy decisions in pulmonary sarcoidosis in comparison to chest radiography, serum ACE and blood T-lymphocytes.

Abstract

In 60 patients with histologically proven sarcoidosis, 67Ga scanning was evaluated in terms of sensitivity and specificity for assessing disease activity and compared with chest radiography, serum ACE and blood T-lymphocytes. While 67Ga scans had the highest sensitivity (94%), the specificity was only 68%. The sensitivity of chest radiography was 80%, of serum ACE and blood T-lymphocytes 77% and 48%, respectively. While in patients with radiographical type I, 67Ga scanning, chest radiography and serum ACE had a sensitivity of 92%-100%, in patients with radiographical type II-III, only 67Ga scans had a sensitivity exceeding 90%. A 67Ga score correlated significantly with serum ACE levels (r = 0.59, P less than 0.001). After effective steroid treatment, 67Ga uptake and serum ACE activities decreased markedly. While in 25% of cases, chest radiography failed to provide reliable information, 67Ga scanning and serum ACE activities always proved useful in evaluating the course of the disease and the patient's response to steroid therapy. A negative 67Ga scan together with normal serum ACE levels seem to have a high predictive value for excluding active sarcoidosis.