Effectiveness of Tc-99m sestamibi compared to Ga-67 in patients with pulmonary sarcoidosis

The authors evaluated the suitability of Tc-99m MIBI to be used as an alternative to Ga-67 in pulmonary sarcoidosis imaging. Studies were performed on 21 patients. Eleven patients (group I) had been on corticosteroid treatment before the study, while 10 patients (group II) had received no treatment. Activity of sarcoidosis was assessed from clinical manifestations of the disease, pulmonary function tests, bronchoalveolar lavage, high-resolution computed tomography, and serum biochemistry. Ga-67 imaging results were abnormal in 73% of patients of group I (n = 8) and 90% of patients of group II (n = 9). Tc-99m MIBI imaging results were abnormal in 0% of patients of group I (n = 0) and 40% of patients of group II (n = 4). The lymph nodes were better demonstrated with Ga-67. Abnormal results of Ga-67 imaging were 100% sensitive to clinically active sarcoidosis, but had a relatively low specificity (33%). In contrast, abnormal MIBI imaging had very low sensitivity (11%). The authors conclude that planar Tc-99m MIBI scintigraphic images are not sensitive for the diagnosis of pulmonary sarcoidosis.