The role of recombinant thyroid-stimulating hormone (rhTSH) in the detection and management of well-differentiated thyroid carcinoma: a roundtable discussion.

A Roundtable meeting of European endocrinologists and nuclear medicine physicians recently examined the role of recombinant human thyroid-stimulating hormone (rhTSH, Thyrogen, thyrotropin alfa, Genzyme Corporation, Cambridge, MA, USA) in the detection and management of well-differentiated thyroid carcinoma. The meeting sought to review clinical work to date and to provide guidance and perspective on the agent's application in everyday practice. The Roundtable included a panel discussion centering on three major topics: 1) rationale for use of exogenous versus endogenous TSH stimulation of radioiodine uptake and thyroglobulin (Tg) production; 2) impact and use of rhTSH in diagnostic follow-up; and 3) role of rhTSH in radioablation. The panel concluded that obtaining TSH stimulation of radioiodine uptake and Tg production exogenously with rhTSH obviates the weeks-long withdrawal from thyroid hormone suppression therapy (THST) needed to obtain such stimulation endogenously. rhTSH administration thereby eliminates morbidity, discomfort and uncertainties of compliance and timing associated with THST withdrawal. Thus compared to withdrawal, rhTSH administration offers important advantages in safety, quality of life, reliability, predictability and convenience to patients and care providers. rhTSH therefore represents a major advance in the diagnostic follow-up of well-differentiated thyroid cancer. By increasing the sensitivity of serum Tg testing during THST, rhTSH administration also improves the sensitivity of diagnostic follow-up. In addition, heightening the sensitivity of Tg testing may permit more selective application of iodine-131 whole body scanning, decreasing the invasiveness of diagnostic follow-up. Clinical studies are underway to confirm the preliminary promise of rhTSH as an adjunct to radioablation of normal or neoplastic thyroid tissue, with emphasis on the therapeutic setting.