Difference between PET scan and bone scan

BC 17 yrs prior. Three months ago, had pet, can and bone scan, mulitple lymph and bone metastastis. Specifically C1-C5, left and right hip, and sternum. Three months of arimdex and three injections of Zometa. Just got initial results from PET and they said nothing is there!!! Do i still need bone scan? Am waiting for oncologist report but i wanted to know if i can be this happy and relieved that meds are working and there is no evidence. Thanks so much--or, do i still need to have bone scan as scheduled because the tests show different things

[Cleveland Clinic]

Dear dee1022:  A PET scan uses glucose to show areas of hypermetabolic activity (areas that are growing rapidly).  A bone scan shows bone damage.  Which tests should be repeated is up to your oncologist but may in part be based on which tests showed what initially.  Your oncologist will be better equipped to interpret results and suggest which tests to do at what intervals.