Existing Web application integration with 3D Slicer

This should be no problem at all. See this post for details: New DICOMweb features: launch Slicer from web browser and download/upload data sets to the cloud using DICOMweb

@pieper as far as I remember, you have already experimented with adding a Slicer launcher button in OHIF viewer (similar to the one in Kheops). Can you give some more details about it?