Drugs to Ease the discomfort of definitive radiation?

We are in a quandry regarding Jasper, our 14 year old dog who just received his second surgery to debulk a soft tissue sarcoma on his front leg.

The plan had been to debulk, wait 2 weeks, then do definitive radiation. We are a little more than a week away from the start of treatment and I have been asking what medications will be used to keep Jasper comfortable during treatment. He is not used to be crated or away from home, and eventually the discomfort of the burns will be difficult. I asked if we could try some of the drugs ahead of time to make sure they will work properly when we need them. No problem.

NOW we are being told that we will have to take Jasper to a behaviorist ...I am supposed to fill out a detailed form and have him analyzed for 2 hours just to get medicines to help him cope with the trauma of radiation treatment. I understand using a behaviorist for long term problems and prescriptions for anti-anxiety drugs, but this is a short term situation brought upon by the rigors of treatment. I am put off, not only by the time and energy it would take for all this analysis, but also by the cost and by the knowledge that surely not every dog with difficulties has to go to a behaviorist...? Won't pain meds and sedatives be enough to keep him comfortable?

Has anyone else's dog had trouble coping with radiation therapy, being confined, dealing with the burns and pain...and if so, what was done to alleviate the discomfort?

Thanks very much. Lisa Braddock