TY - JOUR T1 - Pulmonary <sup>99m</sup>Tc-DTPA aerosol clearance and survival in usual interstitial pneumonia (UIP) JF - Thorax JO - Thorax SP - 916 LP - 923 DO - 10.1136/thorax.56.12.916 VL - 56 IS - 12 AU - N Mogulkoc AU - M H Brutsche AU - P W Bishop AU - B Murby AU - M S Greaves AU - A W Horrocks AU - M Wilson AU - C McCullough AU - M Prescott AU - J J Egan Y1 - 2001/12/01 UR - http://thorax.bmj.com/content/56/12/916.abstract N2 - BACKGROUND Clearance of inhaled technetium 99m-labelled diethylenetriamine penta-acetic acid (99mTc-DTPA) from the lungs is a potential indicator of disease progression in patients with idiopathic pulmonary fibrosis (IPF).METHODS We prospectively analysed the usefulness of this technique for predicting survival in 106 non-smoking patients with usual interstitial pneumonia (UIP) pattern IPF diagnosed by high resolution CT (HRCT) scanning or histological examination (M/F 65/41, mean (SD) age 61 (11) years). DTPA clearance was analysed according to both mono-exponential and bi-exponential models. Half times for the fast (t 0.5 F) and slow (t 0.5 S) components of clearance, the percentage contribution of the fast component (f F ), and half time for mono-exponential approximation to the early part of the clearance curve (t 0.5) were calculated.RESULTS The patients had substantially faster t 0.5(mean 23.9 (9.6) minutes) than normal values (&gt;45 minutes). Thirty seven patients (35%) died during follow up (median 15 months). Univariate Cox regression analysis identified significant predictors of survival as age, forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), total lung capacity (TLC), % predicted TLC, carbon monoxide transfer factor (Tlco), % predicted Tlco, arterial oxygen tension (Pao 2), oxygen saturation,t 0.5 F, and HRCT fibrosis score. Multiple stepwise Cox regression analysis identifiedt 0.5 F(p=0.03, hazard ratio 0.747, 95% CI 0.578 to 0.964), % predicted TLC (p=0.02, hazard ratio 0.976, 95% CI 0.956 to 0.995), % predicted Tlco (p=0.003, hazard ratio 0.960, 95% CI 0.935 to 0.986), and age (p=0.003, hazard ratio 1.062, 95% CI 1.021 to 1.104) as independent predictors of survival.CONCLUSION These data suggest that 99mTc-DTPA clearancet 0.5 Fmeasurement may predict survival in patients with UIP pattern IPF. ER -