One study had shown that undetectable baseline thyroglobulin at 1 month post-surgery was associated with absence of structural disease on post-operative scans (Giovanella et al., 2008), whereas another study showed that undetectable thyroglobulin levels 2–6 months post-surgery was associated with radioactive iodine avid metastatic disease in 12% of cases (Robenshtok et al., 2013). Here, TG is linked to metastatic neoplasm.