Thank you to everyone who responded. My wife and I appreciate you sharing your experinces with us, your good wished and your prayers.
We saw our ENT yesterday. He looked at the suspect spot on the tongue and then he felt it with his fingers. He said that this suspect area was there at our last visit in the first week of November and it had not gotten any bigger.
He said that it may be due to the radiationt therapy since there is discoloration but he proceeded to say that since the pain in the tongue is getting worse it may also be a tumor. To be sure, he scheduled us for a biopsy and if it turns out to be a cancerous growth that of course it needs to be removed. The ENT did not seem overly concerned and we left his office feeling a little better.
Since we had plans to travel overseas, the ENT said that it was OK for us to go and have the biopsy after we return from our trip.