Effect of Lithium Carbonate on Low-Dose Radioiodine Therapy in Early Thyroid Cancer

Phase 2

Completed

Conditions: Thyroid Cancer
Differentiated Thyroid Carcinoma

Interventions: Drug: Lithium Carbonate
Drug: Placebo

Registration Number: NCT00251316

Lead Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Brief Summary: This study will examine the safety and effectiveness of using lithium, which has been used to enhance the effectiveness of high-dose 131I, with a single low dose (30 mCi) of 131I for thyroid ablation in patients with recently diagnosed papillary or follicular thyroid cancer who have had their thyroid gland removed and whose cancer has not spread beyond the thyroid.

Participants are randomly assigned to receive lithium capsules or placebo (look-alike capsules with no active ingredient). They follow a low-iodine diet for 2 weeks before starting treatment and are then admitted to the NIH Clinical Center for study and treatment for 11 days, during which they remain on the low-iodine diet. Blood samples are collected almost every day to analyze thyroid hormones, kidney and liver function, lithium concentrations and other tests.

Detailed Description: Postsurgical thyroid remnant ablation with (131)I is considered standard clinical care for most cases of papillary and follicular thyroid cancer, to eliminate normal thyroid tissue which may contain microscopic cancer. Furthermore, ablation enhances the sensitivity of subsequent (131)I scanning and serum thyroglobulin (TG) measurement for the detection of recurrent or persistent disease. Low dose (131)I (30 mCi) successfully ablates thyroid remnant in 8-61% of cases. This dose can be repeated and result in overall less radiation exposure than that associated with high dose therapy (100 mCi). Ablation achieved with one or more small doses of radioactive iodine is not associated with decreased survival or cancer recurrence. According to the literature there is no difference in the 30-year recurrence rates between groups receiving low and high dose ablation therapy for well differentiated thyroid cancer without distant metastases at the time of initial therapy. The benefits of using low dose of (131)I are minimization of whole body radiation exposure, reduction in side effects and lower cost. Higher rates of successful ablation by low dose of 131I could be achieved by increasing uptake of (131)I and/or lengthening retention of radioiodine in the remnant thyroid tissue. Recombinant human thyroid-stimulating hormone (rhTSH) has been used successfully to increase radioiodine uptake. Lithium has been used to increase radioiodine retention and has been shown to be useful in the treatment of residual or metastatic cancer. The combination of rhTSH and lithium as adjuncts to 30 mCi radioactive iodine (RAI) ablation therapy in low risk thyroid cancer patients may provide a method that reduces the cumulative dose of radioiodine needed to successfully treat thyroid cancer. The specific aim of this study is to determine whether adjunct lithium carbonate improves the success rate of postsurgical ablation of thyroid remnants using low dose (131)I (30 mCi) and rhTSH in low risk patients with differentiated thyroid carcinoma. Patients with well-differentiated papillary or follicular thyroid cancer stage I or II, according to the National Thyroid Cancer Treatment Cooperative Study (NTCTCS) classification at time of surgery, will be enrolled. Eligible patients will have had a total or near-total thyroidectomy within 6 months of enrollment. This randomized, placebocontrolled, double-blind study will permit an evaluation of the risk/benefit ratio of adding lithium as an adjuvant to the already established method of administering low-dose (131)I ablation therapy, to optimize the (131)I retention. All patients will undergo diagnostic rhTSH (123)I whole body scan at the end of the study to assess the success of thyroid ablation.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 34

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Lithium Carbonate	Lithium Carbonate	Patients recently diagnosed with papillary or follicular thyroid cancer who have had their thyroid gland removed and whose cancer has not spread beyond the thyroid may be eligible for this study. Participants in this arm receive lithium capsules.
Placebo	Placebo	Patients recently diagnosed with papillary or follicular thyroid cancer who have had their thyroid gland removed and whose cancer has not spread beyond the thyroid may be eligible for this study. Participants in this arm receive placebo (look-alike capsules with no active ingredient).

Primary Outcome Measures

Name	Time	Method
The Rate of Successful Thyroid Ablation as Defined by Negative Recombinant Human Thyrotropin (rhTSH) Stimulated Radioiodine Whole Body Scan (RAI WBS) at 1 Year.	1 year

Secondary Outcome Measures