Abandon old cast iron toilet flange

Hi Everyone,

I am replacing an old toilet with a wall hung unit due to the location. Going to a wall hung unit allows the bathroom to work much better. Now I need to abandon the old toilet flange and properly seal the cast iron pipe. I will tile over this once it is properly seals off. Question is... how to properly seal off the flange? It is in the basement and set in concrete.

 

If the pipe is no longer connected to the drain just fill it with concrete.

 

It would not be right to leave the abandoned waste arm connected to the building drain, but without knowing the layout of the piping for all of the bath fixtures, it would be impossible to tell you what needs to be done.