[High-resolution CT semi-quantitative score may have a role in predicting short-term response to corticosteroid therapy in idiopathic interstitial pneumonias].

OBJECTIVE: To investigate HRCT semi-quantitative score in the response to corticosteroid treatment and prognosis in idiopathic interstitial pneumonia (IIP) patients.

METHODS: Data from 83 IIP patients admitted in Peking University Third Hospital from January, 2001 to May, 2007 were retrospectively studied. Three sections of HRCT scans were analyzed, including the level of the tracheal carina, left atrium, and right diaphragmatic dome. The mean of percentage of reticular pattern and honeycombing on the 3 HRCT sections was calculated (HRCT score). To predict the sensitivity, specificity, and accuracy of the response to corticosteroid treatment when HRCT score was 10%, 20%, 30%, 40%, 50% as cutoff value. Software SPSS 11.0 was used for statistical analysis, the t test or Mann-Whitney u tests for quantitative variables and the chi-square test for qualitative variables.

RESULTS: The most accurate (70.6%) cutoff value was HRCT score of 20%. In 83 IIP patients 51 cases were treated with corticosteroid. These patients were divided into 2 groups by the HRCT score: HRCT score>or=20% group (n=25) and HRCT score<20% group (n=26). The mortality in hospital was 40.0% in HRCT score>or=20% group and 3.8% in HRCT score<20% group, chi2=9.848, P<0.01. The percentage of effective treatment with corticosteroid was 8.0% in HRCT score>or=20% group and 50.0% in HRCT score<20% group, chi2=10.829, P<0.01. The duration of hospitalization was 3.0 (1.0-6.5) and 1.2 (0.7-2.0) months in HRCT score>or=20% group and <20% group, z=-2.758, P<0.01. The course of IIP before using corticosteroid was 24.0 (4.0-48.0) and 2.0 (1.0-12.0) months in HRCT score>or=20% group and <20% group, z=-2.900, P<0.01. Pathologic pattern was identified in 15 cases in the 2 groups: 4 UIP cases in group HRCT score>or=20%; 1 AIP case, 1 UIP case and 9 NSIP cases in group HRCT score<20%.

CONCLUSIONS: HRCT score helps to predict the recent response to corticosteroids. An HRCT score of 20% was an appropriate cutoff value and showed consistency with pathologic diagnosis.