Table 2. Comparison of Relative Efficacy and Side Effect Profile Between rhTSH and THW Preparation for RAI Treatment of Metastatic Thyroid Cancer.

Reference	Design	rhTSH # patients with distant metastases	THW # patients with distant metastases		Location of distant metastases	Outcome
38	Retrospective observational - patients served as their own historical controls	54	54		Lungs, mediastinum, bones, brain, soft tissue	52% similar outcomes after rhTSH versus THW 27% superior response to rhTSH 16% superior response to THW
39	Subgroup analysis of a retrospective study comparing rhTSH vs THW-aided RAI therapy in high-risk patients (n = 275)	1	3		Lung micro- metastases	Complete response in 1/1 patients in rhTSH group and 1/3 patients in THW group
40	Subgroup analysis of a retrospective study comparing rhTSH versus THW-aided RAI therapy in high-risk patients (n = 84)	4	4		Lung micro- metastases	Complete response 3/4 in rhTSH and 1/4 of THW group (P = .41)
41	Subgroup analysis of a retrospective study comparing rhTSH versus THW-aided RAI therapy (n = 586)	46	65		Lung metastases	Short term response (at 2 years) rhTSH versus THW Excellent 20.9% versus 6.2% (P = NS) Acceptable 14% versus 12.3% (P = NS) Incomplete 65.1% versus 81.5% Long-term response rhTSH versus THW No evidence of disease 23.3% versus 16.1% (P = NS) Persistent disease 76.7% versus 83.9% (P = NS)
42	Retrospective comparison of survival after preparation for RAI therapy of metastatic thyroid cancer with rhTSH-only, THW-only, and rhTSH + THW	rhTSH-only 58	THW -only 35	rhTSH+ THW 82	Lungs, bones	No difference in 5 years survival between rhTSH-only, THW-only, and rhTSH + THW group (P = .80)
43	Retrospective comparison of biochemical and structural response (by RECIST criteria) and side-effects profile of rhTSH vs THW-aided therapy for metastatic DTC	15	41		Lungs, bones, brain, kidney	Biochemical response rhTSH versus THW Tg decrease in 79% versus 70% of patients (P = .42). RECIST criteria response rhTSH versus THW Complete response 7% versus 12%, P = .48, Stable disease 73% versus 56%, P = .20, Progressive disease 20% versus 32%, P = .31 Complications rhTSH versus THW Leukopenia 30% versus 28%, P = .61, thrombocytopenia 10% versus 0%, P = .37 Xerostomia 0% versus 12%, P = .20 Restrictive pulmonary disease 0% versus 2%, P = .73

Abbreviations: DTC = differentiated thyroid cancer; RAI = radioiodine; RECIST = response evaluation criteria in solid tumors; rhTSH = recombinant human thyroid stimulating hormone; THW = thyroid hormone withdrawal