Effects of CT images at different reconstruction energies on radiotherapy planning of patients diagnosed with nonsmall cell lung cancer.

Objective and Aims: We conducted this study to explore the influence of spectral computer tomography (CT) images at different reconstruction energies on the radiotherapy plan of patients with nonsmall-cell lung cancer (NSCLC). Subject and Methods: Here, 38 NSCLC patients were selected to undergo energy spectral scanning. All energy spectral images obtained were then transferred to the Discover™ CT postprocessing workstation to generate 40k eV, 60 keV, 80keV, 100keV, 120keV, and different 140keV single-energy images. Subsequently, the images were imported to the Eclipse planning system, after which an oncologist contoured the target area and organs at risk (OARs) on these single-energy images described above. Furthermore, a physicist then designed radiotherapy plans to conduct statistical analysis on the tissue CT value and target volume of each single-energy image, to compare the dosimetry of different plans about the OARs and the target area. Results: The CT values of gross tumor volumes (GTV), heart, lung, and spinal cord samples subjected to different energy CT images were statistically different (P 0.05), as well as the OARs. Conclusions: When CT images of different energies obtained from the energy spectral CT scans were used in the design of radiotherapy planning, no significant differences were observed in the target area outlines and in the doses caused by energy factors. However, the differences in tissue CT values had statistical significance.