Deborah - The claustrophobia is not uncommon. He should tell his radiation oncologist right away. Have him ask about a drug named Ativan. Its a very polite and non-dramatic drug that might be really helpful. I used a lot during my treatment. Encourage your husband to ask about and USE the drugs available for comfort and sleep. I can tell you that the mask is pretty scary - I hated it. Encourage your husband to join us here too. I'm glad you posted, and please keep coming back. There are MANY wonderful people here who know how to help you both. Be strong. Tom