Regional lung avoidance by CT numbers to reduce radiation-induced lung damage risk in non-small–cell lung cancer: a simulation study

Abstract

Background: Selective avoidance aims at sparing functional lung regions. Here, we preferentially direct radiation to irreversibly nonfunctional lung areas based on planning CT imaging to reduce functional lung damage. Materials and methods: For 12 stage I-IV NSCLC patients, 5 lung substructures were segmented on the planning CT, combining voxels 20HU by 12.5 g (95% CI: 5.4–16.9) and 27.1 g (95% CI: 10.2–32.9) for a median and upper 10th percentile patient susceptibility for damage simulation, respectively. Conclusions: Lung damage avoidance based on CT density is feasible and easy to implement. A biomarker providing a reliable selection of patients with high susceptibility for lung damage will be crucial to show the clinical relevance of this avoidance planning strategy.