Radiat Oncol J.  2014 Mar;32(1):43-47. 10.3857/roj.2014.32.1.43.

CT-based quantitative evaluation of radiation-induced lung fibrosis: a study of interobserver and intraobserver variations

• Heo J
• Cho O
• Noh OK
• Oh YT
• Chun M
• Kim MH
• Park HJ

• KMID: 2051155
• DOI: http://doi.org/10.3857/roj.2014.32.1.43

Abstract

PURPOSE
The degree of radiation-induced lung fibrosis (RILF) can be measured quantitatively by fibrosis volume (VF) on chest computed tomography (CT) scan. The purpose of this study was to investigate the interobserver and intraobserver variability in CT-based measurement of VF.
MATERIALS AND METHODS
We selected 10 non-small cell lung cancer patients developed with RILF after postoperative radiation therapy (PORT) and delineated VF on the follow-up chest CT scanned at more than 6 months after radiotherapy. Three radiation oncologists independently delineated VF to investigate the interobserver variability. Three times of delineation of VF was performed by two radiation oncologists for the analysis of intraobserver variability. We analysed the concordance index (CI) and inter/intraclass correlation coefficient (ICC).
RESULTS
The median CI was 0.61 (range, 0.44 to 0.68) for interobserver variability and the median CIs for intraobserver variability were 0.69 (range, 0.65 to 0.79) and 0.61(range, 0.55 to 0.65) by two observers. The ICC for interobserver variability was 0.974 (p < 0.001) and ICCs for intraobserver variability were 0.996 (p < 0.001) and 0.991 (p < 0.001), respectively.
CONCLUSION
CT-based measurement of VF with patients who received PORT was a highly consistent and reproducible quantitative method between and within observers.

Keyword

Radiation-induced lung fibrosis; Fibrosis volume; Quantitative CT; Interobserver variation; Intraobserver variation

MeSH Terms

Carcinoma, Non-Small-Cell Lung
Evaluation Studies as Topic*
Fibrosis*
Follow-Up Studies
Humans
Lung*
Observer Variation*
Radiotherapy
Thorax
Tomography, X-Ray Computed