Reproducibility of whole-body 131I scan and serum thyrotropin and stimulated thyroglobulin values in patients studied twice after injection of recombinant human thyrotropin
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Recombinant human TSH (rhTSH) is used to increase radioiodine uptake during imaging of thyroid cancer, obviating the need to render the patient hypothyroid. We assessed the reproducibility of radioiodine uptake, serum thyrotropin (TSH), and stimulated serum thyroglobulin (Tg) levels after rhTSH administration.
A retrospective review was performed of patients at Stanford who underwent whole-body 131I scanning for surveillance of thyroid cancer twice after thyroidectomy and 131I ablation, with rhTSH prior to each scan. Forty-eight hour radioiodine uptake, peak serum TSH, and stimulated serum Tg levels for each study were recorded. Paired t tests and correlation analysis were used to assess interexamination repeatability.
Twenty-three patients underwent two scintiscans with rhTSH, for a total of 46 exams. There was no significant difference between percent uptake at 48 h in the paired exams (p=0.40). Serum TSH level was measured in 45 of 46 exams; TSH exceeded 50 mIU/l in all cases, and there was no significant difference between paired TSH levels (p=0.93). All patients had stimulated serum Tg levels measured, with no significant difference between paired Tg levels (p=0.40); after excluding one patient whose Tg changed from 15.8 ng/ml to undetectable between scans without interval treatment, the p value rose to 0.95. There was a strong correlation among paired uptake values (r=0.85, p<0.0001), peak serum TSH (r=0.69, p=0.0003), and stimulated Tg levels (r=0.81, p<0.0001). No discordant scan interpretations were reported.
Forty-eight hour radioiodine uptake, peak serum TSH, and stimulated serum Tg levels after administration of rhTSH are repeatable between studies, demonstrating reproducibility of diagnostic results without rendering patients hypothyroid.
KeywordsThyroid Radioiodine treatment Thyroid cancer
- 7.Ladenson PW, Braverman LE, Mazzaferri EL, Brucker-Davis F, Cooper DS, Garber JR, et al. Comparison of administration of recombinant human thyrotropin with withdrawal of thyroid hormone for radioactive iodine scanning in patients with thyroid carcinoma. N Engl J Med 1997;337:888–96.PubMedCrossRefGoogle Scholar
- 12.Becker D, Charkes ND, Hurley JR, McDougall IR, Price DC, Royal HD, et al. Society of Nuclear Medicine Procedure Guideline for thyroid scintigraphy, version 2.0. Accessible online at http://interactive.snm.org/docs/pg_ch05_0403.pdf. Accessed 6/7/2006.
- 14.Hay ID, Thompson GB, Grant CS, Bergstralh EJ, Dvorak CE, Gorman CA, et al. Papillary thyroid carcinoma managed at the Mayo Clinic during six decades (1940–1999): temporal trends in initial therapy and long-term outcome in 2444 consecutively treated patients. World J Surg 2002;26:879–85.PubMedCrossRefGoogle Scholar
- 16.Schroeder PR, Haugen BR, Pacini F, Reiners C, Schlumberger M, Sherman SI, et al. A comparison of short-term changes in health-related quality of life in thyroid carcinoma patients undergoing diagnostic evaluation with recombinant human thyrotropin compared with thyroid hormone withdrawal. J Clin Endocrinol Metab 2006;91:878–84.PubMedCrossRefGoogle Scholar
- 19.Luster M, Sherman SI, Skarulis MC, Reynolds JR, Lassman M, Hanscheid H, et al. Comparison of radiobiokinetics following the administration of recombinant human thyroid stimulating hormone and after thyroid hormone withdrawal in thyroid carcinoma. Eur J Nucl Med Mol Imaging 2003;30:1371–7.PubMedCrossRefGoogle Scholar