Quantifying Local Radiation-Induced Lung Damage From Computed Tomography

Time and dose-related changes in radiological lung density after concurrent chemoradiotherapy for lung cancer

“…In addition, early medical intervention of RP with steroids improves both clinical and radiological appearance of the patient, which could influence lung density measurements and correlation with clinical endpoints. However, pre-clinical data indicates a good correlation between CT density changes and histopathological changes in lung tissue [9].…”

“…However, such parameters are imperfect predictors as fatal toxicity can also manifest in patients with low V 20 [4]. Preclinical studies have shown that radiological lung density (RLD) changes correlate strongly with histopathological radiation damage and physical endpoints [9]. Available data examining the relationship between radiation dose and subsequently lung damage in humans were derived from older studies which did not use high-resolution computed tomography (CT)-scans and acceptable techniques for co-registration of images, and which were not restricted to patients with lung cancer [10][11][12].…”

Treatment outcomes and patterns of radiologic appearance after hypofractionated image-guided radiotherapy delivered with helical tomotherapy (HHT) for lung tumours

“…38,39 A further limitation is that the scoring of CT changes after lung HHT adopted herein 23,24 is qualitative and may be subjective. Alternative methods, such as the use of CT density changes, may represent an objective measure of lung damage because density changes strongly correlate with histological findings of inflammation, 40 thus allowing for a more robust dose-response relationship based on quantitative data. Likewise, the response assessment based on standard RECIST criteria, which rely on the subjective measurement of lesion diameter on FU imaging, might have failed to distinguish between fibrotic changes from recurrence.…”

Volume-Dependent Expression of In-Field and Out-of-Field Effects in the Proton-Irradiated Rat Lung

“…Measuring the relation between the distribution of in-field and out-of-field tissue damage and the threedimensional dose distribution in radiotherapy patients, using, for example, a recently developed method of analyzing CT scans (15), may yield the information required to develop this new type of NTCP model for use in the clinic.…”

“…Moreover, the effect of changing these predictors can be tested in a better-controlled manner and over a wider range than in clinical studies. Such studies have been performed in our laboratory and have shown dose-volume effects in the rat lung (15)(16)(17)(18). Moreover, it was shown that concomitant irradiation of the heart severely reduces the radiation tolerance of the lung (19,20) and that inclusion of this phenomenon in the critical-volume model was essential to be able to accurately predict the incidence of symptomatic radiation-induced loss of lung function (SRILF) (21).…”