Thanks (and others, too) for the supportive words.
My understanding of the RT machines at Clatterbridge is that they have a built-in CT scanner to properly align the patient with the scanner and to check for the proper state of the bowel and bladder. I'm told that they are the very latest technology, so I think that there should be as little collateral damage as is feasible.
I was surprised, when I went for my planning session, to be told that, because I'm a private patient (funded by work medical insurance) I'll be having my RT in a private RT suite that's completely separate from the main hospital's facilities. Shouldn't make any difference at all to the treatment, but at least it means that there shouldn't be any delays, and it's all a lot more comfortable. The "five star" version of RT!