I believe white spots can show an infection, tumor, or a fracture, dark spots can indicate cancer, but I am not sure//
Did you see your Scan? I ask this because I saw my scan and I looked up bone scans and there are two different types of results (clear background with the radioactive material showing up in black and a black background with the radioactive material showing up white) if it is the Black background and you have what the doctors call hot spots (really bright spots on the scan) it could be the sign of either an infection (which always have infection syptoms (fever, night sweats, swelling, pain, etc) or a tumor, here is where the info gets kind of sketchy.
My Orthopedic Oncologist stated that the tumor I had on my pelvic bone was probably benign and that if it don't light up on bone scan then I was safe, because cancer is what lights up on bone scans because of the increased cellular activity. Well my tumor on my pelvic bone did not light up (yay!) but I have a tumor on my femur that is a really bright spot :(
Now today the same orthopedic oncologist said that he was in a hurry to get a biopsy because I didn't have infection symptoms and because of how much and how bright the tumor showed up. But before he left the exam room he said it could be benign (only after I asked him if it could be)
My take is that it doesn't look good to me but I am still researching on the internet, if I find out more info I will re-post.
Have you had any other test?