treatment center is saying they won't begin treatment until you pay this high co-payment, is aggravation you do NOT need with all you are going through.
I assume the insurance review of the order is to determine the co-payment amount.
For some treatments or drugs insurance companies want a pre-authorization, to affirm why it is necessary verses other treatment protocols.
If the delay is a few days that is one thing, but if it drags out for months before you get a decision that is an entirely different matter.
Regardless, your oncologist ordered this because he or she, from their experience knows this is the best treatment for what you have.
In other words, one way or another, you are going to need this protocol. If the insurance company cannot make a decision on this in an expedited manner, you will have to make the decision to bite the bullet, pay the high co-payment, and then fight for reimbursement from the insurance company or facility administrating the treatments, while waiting for the insurance decision to come through.
You don't need this on top of what you are going through, but the hard truth is you will need to fight this on both fronts.
What are the risks waiting for the insurance company to get back to you?
Regardless what the insurance company says, you need to get the treatments. That is what your physician recommended. If the insurance company cannot give you an answer how long it will take for them to render a decision on the co-payment, and for one reason or another you determine that the risk isn't worth it, start having the treatments done, and fight for reimburment later.
The important thing is getting rid of the cancer.
Sorry what you are going through, but this is about you and your family, and that is what you are fighting for.