Postoperative disease status (i.e., the presence or absence of persistent disease) should be considered in deciding whether additional treatment (e.g., RAI, surgery, or other treatment) may be needed.
(Strong recommendation, Low-quality evidence)
Postoperative serum Tg (on thyroid hormone therapy or after TSH stimulation) can help in assessing the persistence of disease or thyroid remnant and predicting potential future disease recurrence. The Tg should reach its nadir by 3-4 weeks postoperatively in most patients.
(Strong recommendation, Moderate-quality evidence)
The optimal cutoff value for postoperative serum Tg or state in which it is measured (on thyroid hormone therapy or after TSH stimulation) to guide decision-making regarding RAI administration is not known.
(No recommendation, Insufficient evidence)
Postoperative diagnostic RAI whole-body scans (WBS) may be useful when the extent of the thyroid remnant or residual disease cannot be accurately ascertained from the surgical report or neck ultrasonography, and when the results may alter the decision to treat or the activity of RAI that is to be administered. Identification and localization of uptake foci may be enhanced by concomitant single photon emission computed tomography–computed tomography (SPECT/CT). When performed, pretherapy diagnostic scans should utilize 123I (1.5–3 mCi) or a low activity of 131I (1–3 mCi), with the therapeutic activity optimally administered within 72 hours of the diagnostic activity.
(Weak recommendation, Low-quality evidence)
Thyrogen is a thyroid stimulating hormone indicated for:
Diagnostic: Use as an adjunctive diagnostic tool for serum thyroglobulin (Tg) testing with or without radioiodine imaging in the follow-up of patients with well-differentiated thyroid cancer who have previously undergone thyroidectomy.
Limitations of Use:
Ablation: Use as an adjunctive treatment for radioiodine ablation of thyroid tissue remnants in patients who have undergone a near-total or total thyroidectomy for well-differentiated thyroid cancer and who do not have evidence of distant metastatic thyroid cancer.
Limitations of Use:
WARNINGS AND PRECAUTIONS
There have been reports of death in non-thyroidectomized patients and in patients with distant metastatic thyroid cancer in which events leading to death occurred within 24 hours after administration of Thyrogen.
Caution should be exercised in patients who have substantial thyroid tissue still in situ or functional thyroid cancer metastases, specifically in the elderly and those with a known history of heart disease.
Hospitalization for administration of Thyrogen and post-administration observation in patients at risk should be considered.
There are post marketing reports of stroke in young women with risk factors for stroke, and neurological findings suggestive of stroke (e.g., unilateral weakness) occurring within 72 hours of Thyrogen administration in patients without known central nervous system metastases.
Patients should be well-hydrated prior to treatment with Thyrogen.
Sudden, rapid and painful enlargement of residual thyroid tissue or distant metastases can occur following treatment with Thyrogen.
Pretreatment with glucocorticoids should be considered for patients in whom tumor expansion may compromise vital anatomic structures.
The most common adverse reactions reported in clinical trials were nausea and headache.
Pregnancy Category C: Animal reproduction studies have not been conducted with Thyrogen. It is also not known whether Thyrogen can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. Thyrogen should be given to a pregnant woman only if clearly needed.
Nursing Mothers: It is not known whether the drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Thyrogen is administered to a nursing woman.
Pediatric Use: Safety and effectiveness in pediatric patients have not been established.
Geriatric Use: Results from controlled trials do not indicate a difference in the safety and efficacy of Thyrogen between adult patients less than 65 years and those over 65 years of age.
Renal Impairment: Elimination of Thyrogen is significantly slower in dialysis-dependent end stage renal disease patients, resulting in prolonged elevation of TSH levels.