Limited Stage Small Cell Lung Cancer

"My father, 72, was diagnosed with stage 3a small cell lung cancer, due to a long history of smoking. He has completely quit since his diagnosis about 6 months ago. It was an unusual presentation, in that it was only located in one small area in his left lung. So he had surgery and had one lobe, and the cancerous cells removed, then had a pretty significant protocol including both brain and chest radiation. He's lost almost 40 lbs, it is 2 months after his last radiation treatment and he is having great difficulty eating. It takes him "all day" to eat breakfast and lunch. He was doing okay for a few days, eating lots of high calorie foods and had gained five lbs. Then today, he tried drinking water and vomited several times and retreated to his bedroom, not eating anything else all day. He doesn't complain of any pain when eating, just that it's difficult and he has little to know appetite.Is this a normal outcome after chest radiation, especially since it's been two months since the last treatment? Will it go away? When will his appetite, ability to eat, improve? I'm concerned, of course, that he will continue to lose weight and won't make it through the winter. He has trouble staying warm, even with lots of heat and clothes.He appears to be cancer-free for now, which is great, but I worry he won't survive the treatments. Please advise...and thank you...Meg"