When having EBRT at my local hospital I drove myself every day, in those days we used to have to urinate and then drink 2 cups of water prior to every session, I very soon learned where the handy toilet stops were too and from the hospital, so it wasn't a problem.
When I later had HDR Brachytherapy at Mount Vernon, 100 miles from home on an unfamiliar route I made the mistake of driving myself, a 2 hours drive with 5 frantic searches for a toilet, I even gate crashed a corporate conference in a posh hotel, not something I would recommend!
However the nurse had kindly provided me with a couple of those papier mache urine bottles
My local hospital, a standard NHS trust, had an area of the car park set aside for cancer treatment, and whilst attending cancer treatment we got our car park ticket validated free of charge. I can't believe this was a voluntary kind hearted initiative of my local hospital, I suspect it was national NHS policy?