Advances in the detection of residual thyroid carcinoma

The challenge of detecting and anatomically localizing metastatic thyroid cancer deposits has become less daunting with the recent developments in radionuclide technology. The use of serum Tg measurements and the whole body radioiodine scan remain the mainstays of the diagnostic evaluation. The advent of recombinant human TSH makes the preparation for a diagnostic scan much less burdensome and appears to have excellent sensitivity for serious metastatic lesions. The dilemma of an elevated serum Tg associated with a negative DxWBS has been ameliorated somewhat with the newly discovered ability of FDG-PET scanning to localize these less well-differentiated lesions. The real challenge lies in the development of new therapeutic agents to treat metastatic lesions that do not concentrate radioiodine.