Hello,
The Stone of Orthanc library has MPR capabilities. This software library has been used as a building block to create various viewers, including the Stone Web viewer. This includes viewers for nuclear medicine and radiotherapy.
However, as of release 2.5, the Stone Web viewer application does not provide a user interface around those MPR capabilities. This might be included in future versions of the Stone Web viewer, provided that this development can lead to a scientific publication.
If you need MPR features right now in Orthanc, have a look at our plugins for OHIF and VolView.
Regards,
Sébastien-