If your brother is beginning radiation or chemo of the head area, removal of the teeth is a precautionary step to save him many problems and possible removal later. My brother had 16 teeth removed before starting treatment. Check with his caregivers and they can explain the need to you and if you and your brother are still unsure, pack your bags and go help him. It's what we sisters do for our brothers - especially if you are an older sister like me. Anyway, is there anyone he can rely on for help understanding things that are located closer to him? This is really not something a person should go through alone, especially if they are confused.
Tonya