Practical application of recombinant thyrotropin testing in clinical practice

Objective: To review the indications for use of recombinant thyrotropin (rTSH) and outline the details of implementation of rTSH diagnostic testing in patients with treated thyroid cancer. Methods: We discuss the results of published clinical trials that have compared rTSH-stimulated testing with conventional withdrawal of thyroid hormone suppressive therapy. Appropriate candidates for rTSH testing are described, and the typical schedule for rTSH testing and follow-up is presented. An overview of coding and documentation for reimbursement is also provided. Results: Clinical studies have found no significant difference in the combined sensitivity of ¹³¹I scans and serum thyroglobulin measurements for detection of recurrent thyroid cancer after rTSH stimulation versus withdrawal of thyroid hormone therapy. As expected, patients have fewer symptoms and a more favorable mood state after use of rTSH. Patients with thyroid cancer who have undergone total or near-total thyroidectomy followed by ¹³¹I ablation can be considered for rTSH testing. For low-risk patients, two cycles of rTSH testing 1 to 2 years apart, followed by testing every 3 to 5 years, are recommended. For moderate- to high-risk patients who have undergone one cycle of negative levothyroxine-withdrawal testing, two cycles of rTSH testing at a 6- to 12-month interval, followed by testing every 1 to 3 years for at least the first decade of follow-up, are recommended. Most commercial insurance, Medicare, and Medicaid carriers now cover rTSH, either in a prescription drug plan or under major medical benefits. Conclusion: Radioiodine scanning and serum thyroglobulin measurement after intramuscular injection of rTSH are valuable new monitoring options in patients with treated thyroid cancer, avoiding the adverse effects of hypothyroidism.