I had my thyroid removed in 1999 because of papillary carcinoma that had spread significantly through the lymph nodes in my neck, & a resection in 2005 for recurrence, at which point we found out I am also iodine resistant. My yearly (or more often) blood tests are always a little wonky but not alarmingly so. Now for the third year in a row my ALP is high & rising. I have also had an aching thigh for several years, with no obvious cause. My liver checks are all fine. At what ALP level should we start looking into bone metastasis?