Thyroid Stunning

Thyroid stunning is the temporary impairment of thyroid tissue after a diagnostic ¹³¹I dose greater than 3 mCi that has been said to decrease the final absorbed dose in subsequent ¹³¹I radioablation therapy, leading to decreased efficacy of ablation.

More recent reports have cast doubt on the existence of this phenomenon, leading some to suggest that its impact has been overemphasized. Others strongly defend the existence of the phenomenon. We take the conservative approach at our institution and use ¹²³I for diagnostic purposes as much as is possible.

References

• Dam HQ, Kim SM, Lin HC, Intenzo CM. 131I therapeutic efficacy is not influenced by stunning after diagnostic whole-body scanning. Radiology. 2004 Aug;232(2):527-33.
• Gerard SK, Dam HQ. Stunning with 131I diagnostic whole-body imaging of patients with thyroid cancer. Radiology. 2005 Mar;234(3):972-3; author reply 973-4.
• Morris LF, Waxman AD, Braunstein GD. The nonimpact of thyroid stunning: remnant ablation rates in 131I-scanned and nonscanned individuals. J Clin Endocrinol Metab. 2001 Aug;86(8):3507-11.