Actually, according to the EULA one license is required for each computer where RadiAnt is installed.
https://www.radiantviewer.com/dicom-viewer-manual/activation.htm
"I have purchased N licenses. Can I install RadiAnt DICOM Viewer on more than N computers?
No, you need a separate license for each computer (or terminal) on which RadiAnt DICOM Viewer is installed (or used)."