Anyone been through or someone who has ? Any doctors out there ?

My 12 yr old sister has papillary carcinoma (thyroid cancer), she had a complete thyroidectomy followed by radioactive Iodine 131 treatment. Then she had a PET scan which showed 3 metastases (spots) in her lungs where the cancer has spread. This is supposed to be considered the most curable cancer.....but is it still curable at this point? the spots measure less than 0.5cm...if this helps.....please anything you can tell me would be helpful....