Determine the efficacy of Tc-99m DTPA inhalation scintigraphy of lung involvement in patients with systemic lupus erythematoazus

The aim of this study was to determine pulmonary involvement of patientswith Systemic Lupus Erythematozus (SLE) by assessment of pulmonaryepithelial permeability using Tc-99m DTPA aerosol scintigraphy, in order tobegin the therapy regimen as soon as possible.Twenty two nonsmoking women patients with SLE (mean age50.68±12.26 years) and 10 healthy volunteer nonsmoking controls (7 women,3 men; mean age 52.10±12.13 years) underwent Tc-99m DTPA aerosolscintigraphy and chest radiography. All patients underwent thoracal highresolution computed tomography and body plethysmographie tests wereperformed for 18 patients.Subjects inhaled 40 mCi of Tc-99m DTPA with 10-12 liter/minute air flowrate by nebulizer for 4 minutes in the supine position. Scintigraphic data wererecorded for a 30 minutes period dynamic images using a double-headedgamma camera (Infinia, GE Medical Systems, Tirat Hacermel, Israel). Halftime (T½) of Tc-99m DTPA clearance was calculated by placing a linear fit onthe curves that obtained from regions of interest drawn around the peripheryof lungs. Penetration index (PI) was calculated by dividing the peripheral totalcounts by the total counts of lungs on the first minute image.Clearance half time of Tc-99m DTPA in the SLE patients (20.66±3.33 min)was faster when compared with the normal controls (51.06±13.80 min)(p=0.000). There is also a significant difference between PI of patients withSLE (0.25±0.03) and that of controls (0.29±0.04) (p=0.003). No correlationwas found between the Tc-99m DTPA T½ and PI with duration of SLEdisease (p>0.05). No correlation was found between the Tc-99m DTPA T½and PI with the body plethysmographic measurements (p>0.05).As a result, early diagnosis of pulmonary involvement in SLE patients can be determined with assess of pulmonary epithelial permeability changes byTc-99m DTPA aerosol scintigraphy as it is easy and applicable noninvasivemethod. It is also available to determine treatment efficacy in patients followup.Early treatment of the patients can improve their life quality.