Breast cancer and diagnostic scans

I had my lumpectomy early June17 for triple negative breast cancer and have a date to start my chemo next week. I have VHI cover so opted to use this cover for various reasons. I am now told by the hospital secretary that I need to have scan or scans prior to treatment, but as I am unfortunately insured with VHI they will not cover this part of my treatment. I am feeling so stressed at the moment. Has anyone had this experience and how many scans might be required? I believe the cost per scan is in the region of 500euro. Can I have scans as a public patient and the chemo through VHI? or does this not work? The Breast check and surgery was done at UCHG and I met my oncologist there also. Galway123