
Preparation with Recombinant Human Thyroid-Stimulating Hormone for Thyroid Remnant Ablation with 131 I Is Associated with Lowered Radiotoxicity
2008; Society of Nuclear Medicine and Molecular Imaging; Volume: 49; Issue: 11 Linguagem: Inglês
10.2967/jnumed.108.050591
ISSN1535-5667
AutoresPedro Weslley Rosário, Michelle Aparecida Ribeiro Borges, Saulo Purisch,
Tópico(s)Thyroid Disorders and Treatments
ResumoPreparation with recombinant human thyroid-stimulating hormone (rhTSH) for thyroid remnant ablation results in lower extrathyroidal radiation than does hypothyroidism. The objective of this prospective study was to compare the damage caused by 131 I (3.7 GBq) when these 2 preparations are used. Methods: Ninety-four consecutive patients who underwent total thyroidectomy and remnant ablation with 3.7 GBq of 131 I were studied. Thirty patients (group A) received rhTSH, and 64 (group B) were prepared by levothyroxine withdrawal. Damage to salivary glands, ovaries, and testes; hematologic damage; and oxidative injury were evaluated by measurement of serum amylase, follicle-stimulating hormone (FSH), complete blood count, and plasma 8-epi-PGF 2α before and after radioiodine. The 2 groups were similar in sex, age, and the results of baseline assessment. Results: The rate of successful ablation (stimulated thyroglobulin level < 1 ng/mL and negative findings on neck ultrasonography) was 90% in group A and 80% in group B. Considering only patients with a preablation thyroglobulin level greater than 1 ng/mL, these rates were 80% and 70.6%, respectively. Only 1 patient (3.3%) reported transient headaches with rhTSH. Elevated FSH levels after therapy were observed in 4 of 9 (44%) men in group A versus 16 of 18 (89%) in group B ( P < 0.03), with a mean increase of 105% versus 236% ( P < 0.001), respectively. In women, elevated FSH was observed in 1 of 13 (7.7%) patients in group A versus 6 of 30 (20%) in group B ( P = 0.4), with a mean increase of 65% versus 125% ( P < 0.001). Thrombocytopenia or neutropenia occurred in 2 of 28 (7%) patients in group A versus 12 of 56 (21.4%) in group B ( P = 0.1), with a mean decrease of 20% versus 45% and 25% versus 52% ( P < 0.01) for neutrophils and platelets, respectively. Hyperamylasemia and symptoms of acute sialoadenitis occurred in 11 of 30 (36.6%) versus 48 of 60 (80%) ( P < 0.001) and in 9 of 30 (30%) versus 35 of 60 (58.3%) ( P = 0.01), respectively. 8-Epi-PGF 2α was found to be elevated after 131 I in 14 of 25 (56%) patients in group A versus 45 of 45 (100%) in group B ( P < 0.001), with a mean increase of 60% versus 125% ( P < 0.001). Conclusion: The lower radiotoxicity with rhTSH, suggested in dosimetry studies, was confirmed in the present prospective investigation, and this advantage occurred without compromising the efficacy of treatment.
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