I have a CPAP, and definitely could not use it during radiation, even though my side effects from radiation were not that severe. The CPAP, even with the humidifier, dries the nose and mouth out severely, which I found intolerable.

Today, I use my CPAP about half the time, due to the drying issues. Before I use it, I make sure the humidifier is working, and that I moisturize my nose and mouth well.

One positive note -- after completing the treatment and having the tumor eradicated, I snore less, even without the CPAP (according to my spouse). So there is hope.

Best of luck to both of you!!