So upset with BCBS right now

The trial my husband was in didn't work and his cancer has gotten worse, so his oncologists want to do radio embolization, then enter him in another trial in four weeks (he has to wait that long between the last chemo and the new trial).  His main oncologist does not want him to sit idle for weeks, because as he said, the cancer can be aggressive and we don't want to waste that time.  So we met with the interventional radiology oncologists last week and they said we had to get preapproval for the radio embolization, since it is only approved for colorectal cancer (it would be off-lable use).  It is $30,000 per dose (one for each side of the liver).  We found out the next day that it was approved, so we hurriedly set up an appt. on the 25th for the mapping procedure.  Well today, we heard from Georgetown that BCBS has decided to review its decision and may deny it.  They want more documentation to prove it is a necessary treatment.  I cannot believe they would put us through this.  How could they approve it then change their minds?  It may also push the procedure date further out as well, which may also impact his eligibility for the new trial.  We are going through enough already.  I feel it is just cruel that they can do this.  The doctors are putting documentation together to submit to BCBS, but I wonder if there is anything I can do to help as well.