This might help if you follow the link and get your onc to be specific in why they ordered the PET Scan. Is this the Medicare fee or an additional by a private radiologist unit?...Your GP can also order a Pet Scan by signing a Radiology form, should you need a more specific referral for Medicare claim.
http://www.health.gov.au/internet/main/publishing.nsf/Content/pet-nuclear-medicine-imagingAs to loss of income, both in the short and long term - I think it is a huge problem with BC and often not talked about enough.