depends more on the pipe feeding the valve, than the valve itself.
Assume the valve isnt salvageable.
the photo isnt clear enough as to what type of pipe do you have off to the right of the valve, between the valve and radiator?
if it's copper, which is what it looks like, you just remove valve, unsolder or cut pip, and re do the whole angle valve part w same size of copper pipe and a new valve that will fit in.
and yes, you will need to drain the system to do this.
Or, if the valve is ok as is, just ignore the whole problem.