Chin A Yi MD, PhD, Abstract Co-Author: Nothing to Disclose

Kyung Soo Lee MD, Abstract Co-Author: Nothing to Disclose

Man Pyo Chung MD, Abstract Co-Author: Nothing to Disclose

Joungho Han, Abstract Co-Author: Nothing to Disclose

Kyung Min Shin MD, Abstract Co-Author: Nothing to Disclose

Jong Heon Park MD, Presenter: Nothing to Disclose

Tae Sung Kim MD, Abstract Co-Author: Nothing to Disclose

Myung Jin Chung MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To estimate retrospectively the extent of fibrotic score (summation of the extent of reticulation and honeycombing) that can help to predict poor outcome on follow-up studies in patients with fibrotic IIPs by using ROC analysis.

We included 108 patients (M:F = 71:37, age 61 + 8 years) with fibrotic nonspecific interstitial pneumonia (NSIP) (n = 29, M:F = 11:18, age 57 + 12.9 years) and idiopathic interstitial pneumonia (IPF) (n = 79, M:F = 60:19, age 63 + 7.4 years). Patients underwent HRCT and surgical lung biopsy at the time of initial diagnosis and were followed by HRCT for > 3 years. Two chest radiologists scored, independently to the nearest 5% level, the extent of ground-glass opacity (GGO), reticulation, honeycombing, consolidation, fibrotic score and overall lesions detected at initial CT and final follow-up CT (twice at 3-month intervals). A decrease and an increase of > 10% in the overall extent of parenchymal lesions at follow-up HRCT were considered to represent disease improvement and progression, respectively. Each lesion extent was analyzed by ROC curve for the prediction of disease progression. ANOVA was used to compare the areas under each of the ROC curve (AUC).

The improvement of disease on follow-up CT (mean, 43 months) was more frequently observed in NSIP (n = 11, 38%) than in IPF (n = 7, 9%), whereas the progression was observed more frequently in IPF (n = 37, 47%) than in NSIP (n = 5, 17%) (P < .05). ROC curves for disease progression prediction were significant in fibrotic score (AUC = 0.769), reticulation (AUC = 0.713), and honeycombing (AUC = 0.701). In pair-wise comparisons for disease progression, the AUC of fibrotic score was significantly larger than that of honeycombing (P < .05), but not larger than AUC of reticulation (P = .160). At the cut-off value of 20% in fibrotic score, the positive and negative predictive values were 74% and 76% respectively.

The extents of fibrotic score and reticulation are significantly better predictor than other parameters for progressive change of disease extent on follow-up study in patients with fibrotic IIPs. Fibrotic score ≥ 20% may be a useful indicator heralding that IIPs will be progressive on follow-up study.

By measuring fibrotic score at HRCT and by noticing its score > 20% in patients with IIPs, one can predict that the disease will be progressive at follow-up HRCT.

Yi, C, Lee, K, Chung, M, Han, J, Shin, K, Park, J, Kim, T, Chung, M, et al, , The Fibrotic Score at HRCT as a Prognostic Determinant in Patients with Fibrotic Idiopathic Interstitial Pneumonias (IIP): ROC Analysis.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6015001.html