I was meant to be starting six weeks of radiotherapy yesterday around my left eye for lacrimal gland cancer. I went through the whole process of wearing the mask mould and having a tube placed in my mouth to keep my jaws apart. But they said they'd only managed to hit some of the planned fields. I'm not fully sure why they couldn't reach all but it seemed from what they were saying that the planned angles were wrong. They had moved the bed around quite a few times to try and line me up but they said they could not physically get the machine into the right position around me (I'm not fat! But I am very tall.) I was rung later to say they'd have to re-plan it so it wouldn't start again until next Monday. 
Has anyone heard of something like this happening before? Is it common or rare? It's shaken my confidence a bit as it means another delay and I am wondering how experienced the planners are and if there will be more problems next week. Having mentally prepared I just want to get on with it ideally! 

If you've had radiotherapy, how did you find the side effects? How tired were you by the end, and how did it affect your eating etc?