Hi Colin,
One thing worth considering, if you suffer bowel problems as the treatment progesses, is a low fibre diet.
I found that initially I was OK so far as side effects were concerned, but after the first two weeks of EBRT I started to get bowel issues.
These continued and peaked about 2 weeks after treatment was complete.
The advice of my hospital was a to cut out all fresh fruit, dried fruit, green veg, beans, fried food etc and survive on a fairly bland diet of boiled white rice/pasta/potatoes, white bread (nothing brown or wholemeal), chicken and fish.
They even had a diet sheet which was rather counterintuitive, forget 'healthy eating' the only things they recommended having 5 of each day was Jaffa Cakes!
Of course after about a month things settle down and you can resume healthy eating, I celebrated with a red bean and spinnach curry, which is guaranteed to get things moving!
:)
Dave