Recombinant Human Thyrotropin is Helpful in the Follow-Up and 131I Therapy of Patients with Thyroid Cancer: A Report of the Results and Benefits Using Recombinant Human Thyrotropin in Clinical Routine

Abstract

There is no doubt that the availability of recombinant human thyrotropin (rhTSH) is one of the milestones in the management of patients with differentiated thyroid cancer (DTC). It offers the opportunity to obtain representative serum thyroglobulin (Tg) levels and diagnostic whole-body scanning (Dx WBS) with 131I under adequate TSH elevation, while the patient continues to receive thyroid hormone. But rhTSH is also used with success in the treatment of local recurrences and distant metastases. In this retrospective analysis we were able to show that our excellent clinical experiences with the use of rhTSH (rare side effects and high compliance) could also be demonstrated by sufficiently elevated TSH levels and representative stimulated Tg measurements. Since April 2001 most of the patients with thyroid cancer in our hospital have undergone diagnostic examination (205 patients underwent 319 examinations) and 131I therapy (a total of 68 treatments) with rhTSH stimulation excluding the first radioiodine ablation of remnants after initial thyroidectomy. Our results show that under rhTSH stimulation 83.5% (diagnostic group) and 88% (therapy group) of our patients with DTC obtained a TSH level of greater than 80 mU/L after two injections of rhTSH (Thyrogen, Genzyme Corp., Cambridge, MA) 0.9 mg intramuscularly 24 hours and 48 hours before the administration of 131I. Only 2.3% (diagnostic group) and 0% (therapy group) demonstrated TSH levels less than 50 mU/L. Serum Tg levels under rhTSH-stimulated conditions showed that in 81.2% the serum Tg maximum was obtained on day 5. Because of the costs associated with periodically rhTSH-assisted Tg testing and based on the data of other studies we are now testing mainly on day 5 to identify residual tumor mass and to compare these Tg levels in the follow-up. Our experience demonstrates that the administration of rhTSH is a safe, effective, and-from an economic point of view- valuable tool in the management of patients with DTC.