Recombinant human thyroid-stimulating hormone (Thyrogen) in thyroid cancer follow up: experience at a single institution

Recombinant human thyroid-stimulating hormone (Thyrogen((R)); Genzyme Corporation, Cambridge, MA, USA) (rhTSH)-stimulated serum thyroglobulin (Tg) (stim-Tg) and I-131 whole-body scanning (WBS) have been reported to allow follow up of patients with thyroid cancer without the symptoms of thyroxine withdrawal and with equivalent diagnostic information to that obtained after thyroxine withdrawal. The aim of the study was to report results of rhTSH use at the Alfred Hospital, Melbourne, from 1999 to 2006 and in particular to examine the significance of detectable serum Tg after rhTSH in relation to thyroid cancer staging and to compare the sensitivity of rhTSH-stimulated serum Tg to whole-body I-131 scanning (WBS) in the detection of residual and recurrent thyroid cancer. The study was a retrospective chart review. In 90 patients, rhTSH was used for 96 diagnostic episodes and 18 doses of rhTSH were used to facilitate treatment with I-131. In stages I and II cancer (n = 42), of three patients with stim-Tg 1-2 mu g/L, none had identifiable disease, and the three patients who had stim-Tg > 2 mu g/L did not experience recurrent disease during follow up. In contrast, in stages III and IV cancer (n = 43) 2 of 5 with stim-Tg 1-2 mu g/L had identifiable disease and 7 of 10 with stim-Tg > 2 mu g/L had identifiable disease. In Tg-positive, WBS-negative disease, further imaging identified persistent/recurrent disease. rhTSH was effective and safe in the management of thyroid cancer follow up for diagnosis of persistent/recurrent cancer and to enable I-131 treatment. In no case did rhTSH-stimulated WBS identify the presence of disease not also identified by raised basal Tg or stim-Tg. Therefore, in low risk cancer WBS may be omitted.