Fanti S, De Fabritiis A, Aloisi D, Dondi M, Marengo M, Compagnone G, Fallani F, Cavalli A, Monetti N
Department of Nuclear Medicine, S. Orsola-Malpighi Policlinic Hospital, Bologna, Italy.
J Nucl Med. 1994 Dec;35(12):1933-6.
Systemic sclerosis (SS) is frequently associated with interstitial lung disease, but clinical symptoms and radiologic abnormalities may occur late in the course of the disease. This study investigated early pulmonary involvement by assessing the clearance rate of inhaled 99mTc-diethylenetriaminepentaacetic acid (DTPA).
Sixteen patients with proved SS, no clinical pulmonary symptoms and normal chest radiogram were prospectively studied. The 99mTc-DTPA clearance rate was calculated as the time to half clearance (T1/2) and compared with values obtained in healthy nonsmokers.
Six patients showed abnormally increased clearance (T1/2 < 53 min). Rapid clearance was not correlated to SS disease duration or to abnormal pulmonary function tests. Five of six patients with abnormally increased clearance underwent high-resolution CT, which in all five demonstrated pathologic findings that were suggestive of early interstitial disease.
These findings indicate that in SS asymptomatic patients may frequently present with abnormal 99mTc-DTPA clearance; 99mTc-DTPA lung scintigraphy may allow early detection of subclinical pulmonary involvement in SS.
