Networker and CloudBoost requirements?

We currently run NetWorker 8.2 backups to VTL then clone to physical tape.  Our current licensing architecture is still the old method - by number of VTL slots, not by volume.  We would like to implement CloudBoost in order to remove our reliance on tape.  My question is this:  Do we need to install a Data Domain to replace our VTL in order to use CloudBoost or can we implement CloudBoost now, replacing our VTL when it is up for refresh?

Thank you.