Research Article

Serum thyroglobulin concentrations and whole-body radioiodine scan in follow-up of differentiated thyroid cancer after thyroid ablation.

Br Med J 1979; 2 doi: (Published 04 August 1979) Cite this as: Br Med J 1979;2:298
  1. S C Ng Tang Fui,
  2. R Hoffenberg,
  3. M N Maisey,
  4. E G Black


    Measurement of serum thyroglobulin (Tg) concentrations and whole-body radioiodine scan were performed simultaneously during follow-up of 32 patients with differentiated thyroid cancer who had undergone thyroid ablation by operation and radioiodine. Almost all patients in whom serum Tg was undetectable had normal scans. Concentrations exceeding 50 ng/ml were invariably associated with residual or metastatic tumour uptake in the scan. Out of 21 observations of detectable values below 50 ng/ml, 14 were in patients whose scans showed subclinical or sub-radiological tumour uptake and seven in patients with normal scans. The sensitivity of serum Tg as a tumour marker compared favourably to that of the whole-body scan. A scan is unnecessary when serum Tg is undetectable, but in patients with detectable serum Tg concentrations, particularly if these are below 50 ng/ml, a scan is important to assess and localise tumour uptake of iodine before advising treatmet with iodine-131.