My father had hodgkins lymphoma and has fought it off after chemo and radiation, but his white blood cells seem to have stopped producing on its own unless he injects neupogen daily. It has been 8+ weeks since last radiation treatment. Is this permanent?

Now that I have more room to write, let me put in more details. My father had a kidney transplant 15 years ago and his immune system is weakened as a result. He went through only half of the normal chemo course because the chemo was too hard on his body. He also went through radiation afterwards using a lowered dose for similar reasons. His PET scan after chemo showed the cancer was gone. The chemo was hard on him, but he eventually recovered. Then he went for radiation therapy just in case there were any remaining cancer cells that the chemo may have missed. He became neutropenic several times during his chemo treatments but each time he was able to recover eventually. However after the radiation, his white blood cell count has dropped and haven't come back up on its own. He's had daily neupogen shots which boosted his numbers but once they took him off of it, the numbers have fallen again. The doctors haven't been able to give him a straight answer on what's going on. It's been a lot of "your body might still be recovering from the radiation, let's wait and see." As noted, it's been more than 8 weeks since his last radiation treatment. I'm sure his compromised body from the transplant is causing recovery to be slower than normal. But has anyone been in this situation where the white blood cell count doesn't come back up on its own? What are your experiences and treatments for this? I can't imagine him having to inject himself daily with neupogen for the rest of his life. I don't think donor bone marrow transplant is an option because I don't know if his body will take it. And I don't believe he had any bone marrow taken out of him before his chemo treatment for autologous transplant. Thank you in advance for your responses.