My Thai wife has breast cancer. Apart from a chest and abdomen CT scan she was sent for a Gamma Bone Scan (Scintigraphy). The report was most interesting and informative (for me as a lay person anyway). The 'Impression' (bottom line) was; 'No evidence of Bone Metastasis'. However, other potentially useful 'warnings' were given. For example; 'increased uptake of radiotracer was noted in the lumbar vertebrae probably due to degenerative change'. Also; 'increased radiotracer activity in the bilateral kidneys is noted'. Cancer doctor confirmed no problem, she agreed that the wear and tear is normal at 56 years. Chemotherapy causes the kidneys to appear in that way. Just a suggestion, but could this test be helpful to the OP as it appears to be more 'targeted' towards cancer?