Question: what to say to someone going through radiotherapy?
Answer: “I'm here for you.” Show up for your loved one and remain by their side as they go through this process. ... 
“You are in my thoughts and prayers.” ... 
“This stinks.” ... 
“Let me help you with…” ... 
Tell a Joke. ... 
“You are not alone.” ... 
“Any time you need to talk, I'll listen.” ... 
“What day works for a visit?”