Different kinetics of lung clearance of technetium-99m labelled diethylene triamine penta-acetic acid in patients with sarcoidosis and smokers.

Abstract

The rate of clearance from the lungs of inhaled technetium-99m labelled diethylene triamine penta-acetic acid (99mTc-DTPA) is often increased in interstitial lung disease as well as in smoking. In smokers a bi-exponential clearance course of 99mTc-DTPA when measured over 3 h has previously been shown. This study was performed to compare the kinetics of clearance of 99mTc-DTPA, measured for 3 h, in sarcoid patients and healthy smokers. Forty-one never-smoking patients with sarcoidosis and radiological signs of intrathoracic disease were studied. The results were compared with those of 16 healthy current smokers and of 14 healthy never-smokers reported previously. A mono-exponential clearance equation described the clearance in 22 of the sarcoid patients and all normal never-smokers, but with a shorter average tracer half-life in the patients (P < 0.05). In 19 patients and all smokers a bi-exponential equation gave a significantly better curve fit. The rate of clearance of the slow component was higher in patients with sarcoidosis than in smokers (P < 0.05). The fraction of the tracer cleared by the fast clearance component was smaller in patients with sarcoidosis than in smokers (P < 0.01). Differences in kinetics of clearance of 99mTc-DTPA in sarcoidosis and smoking could thus be demonstrated, suggesting that the abnormal clearance is caused by diverging pathophysiological mechanisms.

• Authors: I Brådvik, P Wollmer, E Evander, H Lárusdóttir, B Blom-Bülow, B Jonson
• Journal: European journal of nuclear medicine (Eur J Nucl Med) Vol. 21 Issue 11 Pg. 1218-22 (Nov 1994) ISSN: 0340-6997 [Print] Germany
• PMID: 7859774 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Technetium Tc 99m Pentetate

Topics

• Adult
• Female
• Half-Life
• Humans
• Lung (diagnostic imaging, physiopathology)
• Male
• Radionuclide Imaging
• Sarcoidosis, Pulmonary (diagnostic imaging, physiopathology)
• Smoking (physiopathology)
• Spirometry
• Technetium Tc 99m Pentetate (pharmacokinetics)
• Time Factors