Clearance of technetium-99m-DTPA in pulmonary sarcoidosis

Background. The aim of this study was to explore the possible association of the lung clearance of 99mTc- DTPA scan with HRCT lung abnormalities and with the pulmonary function tests [PFTs] in patients with sarcoidosis. Methods. We studied prospectively 15 patients [5 males, 10 females] of median age 46yr [range 27-67] with histologically proved sarcoidosis. HRCT scoring included the sum of the severity and extent of lymph node enlargement and parenchymal involvement. Results. The mean DTPA clearance half-time [Ï„ 1/2 <40 min] was found [mean [SD]] 38.3+4.5min. The lymph node enlargement was found 34% and the parenchymal involvement 12%. DTPA clearance was negatively correlated with the parenchymal involvement [r= -0.651, p=0.009]. The HRCT parenchymal abnormalities were found significantly correlated with PFTs [FVC [r= -0.65, p=0.008] and TLCO [r= -0.76, p=0.02]. Conclusions. Our data suggest a moderate association between 99mTc-DTPA scan and HRCT in pulmonary sarcoidosis. However, further studies in large scale of sarcoid patients are needed to clarify the role of this novel methodology in the evaluation and follow-up of this disorder.