Merge RTstructures with Dicom

Dear Slicer Users,
I have CT slices and RTstructure set with contours (painted organs in the CT slices). Both are DICOM. I would like to permanently modify CT slices with these contours and export new CT slices in DICOM (so new DICOM will be CT with contours). Simply, I would like to merge both files end export.
Do you have any ideas how to do that? I have 3years old Slicer (maybe I have to download new version for better features…)
Thank you in advance