new and have questions

My stepdad has lung ca / 2 positive nodes that has spread to two lesions in the brain. He's had chemo and radiation to lung and radiation to head....doctor is worried about his throat now...his voice is hoarse and he's coughing and clearing throat...more....any ideas on this? Wondering if anyone out there had the same experience? What should my mom and I be prepared for next? I'm trying to find as much info as I can on what's to come but I keep hitting a brick wall. Any advice? tracy