Scot
UAV is a NCI designated Cancer Center.

I would think it would be a very competent place and would provide a high standard of comprehensive care consistent with treatment guidelines.

Perhaps there is just a lot of miss-communication between you, your sister and your BIL's oncology team at UAV.

During treatment, most of us saw numerous doctors weekly. So perhaps you could arrange a visit and accompany your sis and BIL to his appointments and ask for some clarifications.