Pulmonary clearance of aerosolized 99mTc-DTPA in sarcoidosis I patients

Sarcoidosis frequently affects the lungs of patients. Pulmonary clearance scintigraphy with Technetium-99m-diethylenetriaminepentaacetic acid ((99m)Tc-DTPA) aerosol may assess pulmonary involvement of sarcoidosis patients. The study investigated early pulmonary involvement of sarcoidosis I patients by assessing the pulmonary clearance of inhaled (99m)Tc-DTPA aerosol and the character of pulmonary clearance though systemic steroid therapy.

The pulmonary clearance of (99m)Tc-DTPA aerosol was investigated in 24 patients with suspected stage I sarcoidosis and 20 non-smoking healthy controls over 18 months. The radiological finding was evaluated by chest computed radiography (CR) and high resolution computed tomography (HRCT) and the histological diagnosis was performed by transbronchial lung biopsy and/or Scalen node biopsy. The sarcoidosis I patients with ocular involvement underwent 1 year-systemic steroid therapy and were followed up over totally 18 months.

The histological diagnosis was proved in 13 out of the 24 patients that had no lung filed involvement on CR and HRCT. Accelerated pulmonary clearance of (99m)Tc-DTPA was observed in 10 out of the 13 sarcoidosis I patients. Nine out of 13 sarcoidosis I patients underwent systemic steroid therapy due to ocular involvement and the accelerated pulmonary clearance responded to therapy and improved in all of the 9 over 18 months.

Acceleration of (99m)Tc-DTPA pulmonary clearance may be observed in sarcoidosis I patients and the acceleration will respond to systemic steroid therapy. Pulmonary clearance scintigraphy with (99m)Tc-DTPA aerosol may be useful for assessing pulmonary involvement before radiological changes emerge and sarcoidosis I patients with accelerated pulmonary clearance may undergo systemic steroid treatment.