That is what his doctors said at the time.
I'm still not sure why it's so important to pin down why he dropped out of the Senate race in the first place.
I'm not sure why it's so important to you to try to perpetuate myths.
His doctors said "Giuliani can do this therapy and campaign for this particular Senate seat at the same time"? In that case I think they too were being presumptuous. Whether or not someone can do treatment X and at the same time engage in a political campaign is not purely a medical question that doctors are qualified to definitively sound off on. Doctors are not experts nor, probably, are they particularly knowledgeable on what is required of a person engaging in a political campaign.
Presumably, Giuliani didn't think he could do both. Or maybe let's say he just didn't want to try, because he wanted to focus on the treatment. So he didn't.
What's your problem with that? You've got a problem with that? Why the heck would you have a problem with that?