Hi Kelly,

"Also, something that the ENT doctor said to us which is kind of unsettling to me is " If my father continues to lose weight but getting the calories then we have to look into the possibiliy that a second cancer has developed. "

From what you are saying - your father is NOT getting the calories he needs, from either food or a supplement like Ensure. So, while I understand what he was saying (because I am a person that continued to lose weight and had the cancer spread) your father's weight loss is not unexplained. SCC can spread to other parts of the body if not caught in time.
As far as the CT Scan mine was a month after I finished radiation and I was told it was to be used as a baseline for continued monitoring.
You might ask when they schedule the CT Scan what area they are scanning and if they are going to scan the chest, abdomen and pelvis as a precaution?

Good luck and take care,

Dinah