@phyllisg, memory or cognitive issues can happen during or after treatment. You may have heard it called "brain fog." Most often it is associated with chemotherapy, but radiation can cause it too. Read more here:

- Memory or Concentration Problems and Cancer Treatment https://www.cancer.gov/about-cancer/treatment/side-effects/memory

Did your husband have any cognitive decline before cancer? How often does he have radiation and how many more treatments to go?