Radiation Therapy in Youth Caused Current-Day Hair Loss?

Greetings,
I just learned that my husband had been diagnosed as a child with cancer in one of his testicles. He underwent radiation and had lost hair on his head. Could this radiation have caused some permanent hair loss on his head? He is bald at the crown.
Thank you for you time

It is not clear if he received radiation to the head. Assuming that his radiation was more in the groin, then I doubt that it is producing hair loss. He needs to get a working diagnosis with mapping of his scalp for miniaturization. Treating the balding crown has some good solutions for him but first he needs to get a working diagnosis.