Hair questions

There are some questions concerning hair in this movie. Did the female lead shave her head and put makeup on it or did they use a bald cap and good makeup? And MUCH MORE IMPORTANT: why in the bloody hell did she and all the other patients dealing with this hair loss still have freaking EYEBROWS???? It makes no sense. I might be getting something wrong here, but hair loss due to chemotherapy affects ALL OF YOUR BODY HAIR. How could they get that wrong? There is no way that all your hair on top of your head falls out and you still have FREAKING EYEBROWS!!!

I don't know HOW they could get it wrong, but it's a major logic flaw to me.