I actually just answered a similar question. http://support.advancedcustomfields.com/forums/topic/delete-repeater-row-not-staying-deleted-with-onditional-logic/
In you case, rather than
if (get_field('content_field'))
You should do
$selection = get_field('radio_field');
if ($selections == 'choice 1') {
// output code for choice 1
}
if ($selections == 'choice 2') {
// output code for choice 2
}
Or you could combine them into an if elseif else statement. Of even better yet I would probably choose a switch statement.