Unmerge Kde in gentoo
Update
emerge --ask -C `eix -C kde-base --only-names --installed`
nano /etc/make.conf
and delete kde from the USE flags, remove qt3support and qt4 also if you don’t need them anymore
emerge -uavtqND world"
Now you should have just a few kde packages in the list you got as an output of that command, it’s your choice to leave them or unmerge them manually, with unmerge -pv –depclean