Faculty Collaboration Database

Quantification of radiation-induced lung damage with CT scans: the possible benefit for radiogenomics. Acta Oncol 2013 Oct;52(7):1405-10

Date

08/21/2013

Pubmed ID

23957564

DOI

10.3109/0284186X.2013.813074

Scopus ID

2-s2.0-84884545769 (requires institutional sign-in at Scopus site)   45 Citations

Abstract

BACKGROUND: Radiation-induced lung damage (RILD) is an important problem. Although physical parameters such as the mean lung dose are used in clinical practice, they are not suited for individualised radiotherapy. Objective, quantitative measurements of RILD on a continuous instead of on an ordinal, semi-quantitative, semi-subjective scale, are needed.

METHODS: Hounsfield unit (HU) changes before versus three months post-radiotherapy were correlated per voxel with the radiotherapy dose in 95 lung cancer patients. Deformable registration was used to register pre- and post-CT scans and the density increase was quantified for various dose bins. The dose-response curve for increased HU was quantified using the slope of a linear regression (HU/Gy). The end-point for the toxicity analysis was dyspnoea ≥ grade 2.

RESULTS: Radiation dose was linearly correlated with the change in HU (mean R(2) = 0.74 ± 0.28). No differences in HU/Gy between groups treated with stereotactic radiotherapy, conventional radiotherapy alone, sequential or concurrent chemo- radiotherapy were observed. In the whole patient group, 33/95 (34.7%) had dyspnoea ≥ G2. Of the 48 patients with a HU/Gy below the median, 16 (33.3%) developed dyspnoea ≥ G2, while in the 47 patients with a HU/Gy above the median, 17 (36.1%) had dyspnoea ≥ G2 (not significant). Individual patients showed a nearly 21-fold difference in radiosensitivity, with HU/Gy ranging from 0 to 10 HU/Gy.

CONCLUSIONS: HU changes identify objectively the whole range of individual radiosensitivity on a continuous, quantitative scale. CT density changes may allow more robust and accurate radiogenomics studies.

Author List

De Ruysscher D, Sharifi H, Defraene G, Kerns SL, Christiaens M, De Ruyck K, Peeters S, Vansteenkiste J, Jeraj R, Van Den Heuvel F, van Elmpt W

Author

Sarah L. Kerns PhD Associate Professor in the Radiation Oncology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adult
Aged
Aged, 80 and over
Carcinoma, Non-Small-Cell Lung
Dyspnea
Female
Genomics
Humans
Lung Neoplasms
Male
Middle Aged
Prognosis
Prospective Studies
Radiation Pneumonitis
Radiography, Thoracic
Radiotherapy
Radiotherapy Dosage
Retrospective Studies
Small Cell Lung Carcinoma
Tomography, X-Ray Computed