Here's my two cents.

A tumor with clear margins is nothing like a tumor where the margins are not clear. John had the latter. The first time he saw the RO, the doctor repeated that twice but he didn't give us an explanation as to why the remark was pertinent. At the time, I had not yet clued into the importance of having clear margins.

I guess, with no clear margins, the radiation had to be stronger and cover a bigger area -- this is only my own reasoning. If that was the case, that was the reason why John had such problems with scarring and swallowing and everything else.

I doubt if the doctors would dial back the treatment in the case in the article if the cancer didn't have clear margins.