Mistake with a ripple effect

I got the results of my CT scan and it looked clean which is great news. But I also found out that they had used something called "contrast" which contains iodine. I have been on a low iodine diet for a while now getting ready for radiation which is Oct 23rd. So now I get a call telling me they need to push back the radiation. They will call me to let me know when it will be but I am livid. One mistake and now my treatment is delayed by 2 months.