Low-level laser therapy in chronic autoimmune thyroiditis: a pilot study.

BACKGROUND AND OBJECTIVES: Chronic autoimmune thyroiditis (CAT) remains the most common cause of acquired hypothyroidism. There is currently no therapy that is capable of regenerating CAT-damaged thyroid tissue. The objective of this study was to gauge the value of applying low-level laser therapy (LLLT) in CAT patients based on both ultrasound studies (USs) and evaluations of thyroid function and thyroid autoantibodies. STUDY DESIGN/MATERIALS AND METHODS: Fifteen patients who had hypothyroidism caused by CAT and were undergoing levothyroxine (LT4) treatment were selected to participate in the study. Patients received 10 applications of LLLT (830 nm, output power 50 mW) in continuous mode, twice a week, using either the punctual technique (8 patients) or the sweep technique (7 patients), with fluence in the range of 38-108 J/cm(2). USs were performed prior to and 30 days after LLLT. USs included a quantitative analysis of echogenicity through a gray-scale computerized histogram index (EI). Following the second ultrasound (30 days after LLLT), LT4 was discontinued in all patients and, if required, reintroduced. Triiodothyronine, thyroxine (T4), free T4, thyrotropin, thyroid peroxidase (TPOAb) and thyroglobulin (TgAb) antibodies levels were assessed before LLLT and then 1, 2, 3, 6, and 9 months after LT4 withdrawal. RESULTS: We noted all patients' reduced LT4 dosage needs, including 7 (47%) who did not require any LT4 through the 9-month follow-up. The LT4 dosage used pre-LLLT (96 +/- 22 microg/day) decreased in the 9th month of follow-up (38 +/- 23 microg/day; P < 0.0001). TPOAb levels also decreased (pre-LLLT = 982 +/- 530 U/ml, post-LLLT = 579 +/- 454 U/ml; P = 0.016). TgAb levels were not reduced, though we did observe a post-LLLT increase in the EI (pre-LLLT = 0.99 +/- 0.09, post-LLLT = 1.21 +/- 0.19; P = 0.001). CONCLUSION: The preliminary results indicate that LLLT promotes the improvement of thyroid function, as patients experienced a decreased need for LT4, a reduction in TPOAb levels, and an increase in parenchymal echogenicity.

High prevalence of side effects after recombinant human thyrotropin-stimulated radioiodine treatment with 30 mCi in patients with multinodular goiter and subclinical/clinical hyperthyroidism.

BACKGROUND: Treatment of multinodular goiters (MNGs) is highly controversial. Radioiodine (RAI) therapy is a nonsurgical alternative for the elderly who decline surgery. Recently, recombinant human thyrotropin (rhTSH) has been used to augment RAI uptake and distribution. In this study, we determined the outcome of 30 mCi RAI preceded by rhTSH (0.1 mg) in euthyroid (EU) and hyperthyroid (subclinical/clinical) patients with large MNGs. METHODS: This was a prospective cohort study. Forty-two patients (age, 43-80 years) with MNGs were treated with 30 mCi RAI after stimulation with 0.1 mg of rhTSH. Patients were divided into three groups, according to thyroid function: EU (n = 18), subclinically hyperthyroid (SC-H, n = 18), and clinically hyperthyroid (C-H, n = 6). All patients underwent a 90-day low-iodine diet before treatment, and those with clinical hyperthyroidism received methimazole 10 mg daily for 30 days. Serum TSH, free thyroxine (FT4), total triiodothyronine (TT3), and thyroglobulin were measured at baseline and at 24, 48, 72, 168 hours, and 1, 3, 6, 9, 12, 18, 24, and 36 months after therapy. Thyroid volume was assessed by computed tomography at baseline and every 6 months. RESULTS: Patients had high iodine urinary excretion (308 +/- 108 microg I/L) at baseline. TSH levels at baseline were within the normal range (1.5 +/- 0.7 microU/mL) in the EU group and suppressed (<0.3 microU/mL) in the SC-H and C-H groups. After rhTSH, serum TSH peaked at 24 hours reaching 12.4 +/- 5.85 microU/mL. After RAI administration, patients in both hyperthyroid groups had a higher increase in FT4 and TT3 compared with those in the EU group (p < 0.001). Thyroglobulin levels increased equally in all three groups until day 7. Thyroid volume decreased significantly in all patients. Side effects were more common in the SC-H and C-H groups (31.4% and 60.4%, respectively) compared with EU patients (17.8%). Permanent hypothyroidism was more prevalent in the EU group (50%) compared with the SC-H (11%) and C-H (16.6%) groups. CONCLUSIONS: Patients with MNG may have subclinical and clinical nonautoimmune iodine-induced hyperthyroidism. Despite a low-iodine diet and therapy with methimazole, hyperthyroid patients have a significantly higher increase in FT4 and TT3 levels after RAI ablation. This can lead to important side effects related mostly to the cardiac system. We strongly advise that patients with SC-H and C-H be adequately treated with methimazole and low-iodine diet aiming to normalize their hyperthyroid condition before rhTSH-stimulated treatment with RAI.

Cardiovascular assessment of hyperthyroid patients with multinodular goiter before and after radioiodine treatment preceded by stimulation with recombinant human TSH.

Treatment of large multinodular goiter (MNG) with radioiodine preceded by recombinant human thyrotropin (0.1 mg rhTSH) has been shown to be a safe alternative for patients with comorbidities that preclude surgery. However, the increase in serum thyroid hormones that follows both treatments may be harmful for some patients, particularly those with underlying cardiovascular disease. In this study, we evaluated cardiac parameters (clinical, ECG, 24-h Holter, Doppler echocardiogram, treadmill stress test) in 27 of 42 patients (ages 42-80 years) with large MNGs who were treated with rhTSH before receiving 30 mCi radioiodine therapy. At baseline, 18 patients had subclinical and six patients had overt iodine-induced hyperthyroidism. All patients had a transient surge in serum levels of free T4 and total T3 into the hyperthyroid range after therapy. However, repeated cardiac evaluation did not show significant changes as compared with baseline evaluation. In conclusion, rhTSH stimulated RAI treatment of MNG did not affect structural and functional parameters of the heart, despite transient high-serum levels of thyroid hormones.

Administration of a single dose of recombinant human thyrotrophin enhances the efficacy of radioiodine treatment of large compressive multinodular goitres.

OBJECTIVE: Patients with very large multinodular goitres, frequently found among elderly people, often suffering from cardiovascular or other disabling disorders, may be considered as unsuitable for surgery. We have evaluated the feasibility of relatively high-dose 131I therapy in such patients. As subclinical or clinical hyperthyroidism is commonly found in these patients, associated with a low radioiodine (RAI) uptake at 24 h, we pretreated a group of patients with a single intramuscular injection of recombinant human TSH (rhTSH 0.45 mg) in order to increase the uptake of the therapeutic dose of RAI. DESIGN AND PATIENTS: Forty-one patients with large, long-standing multinodular goitres, were recruited for this study. After a careful and detailed clinical and laboratory evaluation, 34 patients (28 women, six men) were included and randomly assigned to group 1 (control, n = 17, 15 women, two men, age 63.1 +/- 11.2 years) receiving only RAI. Patients in group 2 (n = 17, 13 women, four men, age 63.6 +/- 12.3 years) received the therapeutic dose of RAI, having been pretreated (24 h) with 0.45 mg of rhTSH. Both groups of patients were submitted to a low iodine diet, 4-6 months before RAI treatment, while seven thyrotoxic patients also received methimazole (40 mg/day) until they reached euthyroidism. Ultrasonographic studies were performed for all patients and fine-needle aspiration biopsy (FNAB) were performed on one or two nodules before RAI treatment. RAI was given as a single oral dose to the hospitalized isolated patients. Blood samples for thyroid function tests and serum thyroglobulin (Tg) were collected daily during the first week following RAI treatment, and at 1, 3, 6, 9 and 12 months thereafter. MEASUREMENTS: Goitre volume was estimated by computed tomography scan. Thyroid function tests (total T3, free T4, TSH and serum Tg) were assayed with commercial kits. Urinary excretion of iodine was assayed by the Sandell-Kolthoff method. RESULTS: After the RAI therapeutic dose, serum thyroid function tests were carried out daily for the first week and then on a monthly basis (1, 3, 6, 9 and 12 months). Serum TSH levels rose to a peak level of 45.9 +/- 19.1 mU/l (24 h) in group 2 returning to normal at 72 h. Free T4 serum concentrations rose significantly to 59.35 +/- 21.61 pmol/l at 48 h (in group 2) returning to normal at 7 days. Similarly, serum TT3 also peaked above normal levels only in group 2 (6.12 +/- 1.89 nmol/l) at 24 h. Serum Tg increased in both groups (significantly higher in group 2) and remained elevated during the following 12 months. Both groups had a significant reduction in goitre volume at 12 months (group 2: 57.8%vs. group 1: 39.7%, P < 0.05). Hypothyroidism was detected after RAI treatment, respectively, in 21.4% (group 1) and 64.7% (group 2), of the patients at 12 months. CONCLUSIONS: Our results indicate that the use of hTSH increased the efficacy of the RAI therapeutic dose. This was basically due to an increased uptake of the radionuclide (as a consequence of the higher serum TSH levels) and a more extensive distribution of 131I within the nodules of the multinodular goitre. A more intense radiation effect was reflected in there being a higher output of serum Tg and thyroid hormones (group 2). As a consequence this group had a significantly higher reduction of the goitre volume. Also incidence of hypothyroidism post-RAI was significantly higher in group 2. We concluded that pretreatment with rhTSH in elderly patients with large multinodular goitres increases the uptake of the RAI therapeutic dose, thereby significantly reducing the multinodular goitre volume and relieving the compressive symptoms with relatively few side-effects.