Can you have a kidney transplant while undergoing radiation treatment?

Need specifics. If you are receiving radiation treatments to treat a cancer, it would depend on the type of cancer, where it was located, and the success of it's treatment. You should discuss this with your transplant team.
See below. If you are undergoing radiation for treatment of a cancer, a kidney transplant is not feasable. Generally speaking a transplant center will not perform a kidney transplant on persons who are diagnosed with cancer and within 2-5 years after having a cancer treated and going into remmission. These decisions are at the discretion of individual transplant centers.

Related Questions

Treatment with infliximab might interfere with future transplant drugs? Or leads to important change in antibodies: hard to get a kidney transplant?

No. The effect of Infliximab is to block temporarily tnf, should not affect future transplants. In some people some antibodies against the drug may form, but no significant consequence to your question. Read more...