Show your dad the pictures of your trip. The summer I was doing radiation I had to miss my annual trip to Maine. We go every year, for about 2-3 weeks, and it's a time for me to be with my mom, brothers, sisters and all our kids. Boy did we miss it that summer. My mom talked about not having anyone come out of respect for me not being able to come. I put that to rest real quick and then waited each day for the mailman to come with the pictures they sent to me.
Do your father a favor and just treat him like you always have. He's going to need that.

SCC Left Mandible. Jaw replaced with bone from leg. Neck disection, 37 radiation treatments. Recurrence 8-28-07, stage 2, tongue. One third of tongue removed 10-4-07. 5-23-08 chemo started for tumor behind swallowing passage, Our good friend and much loved OCF member Minnie has been lost to the disease (RIP 10-29-08). We will all miss her greatly.