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Objective: Elimination of thyroid antigens by total thyroid ablation (TTA), namely, thyroidectomy followed by radioiodine, may be beneficial for Graves' Orbitopathy (GO). TTA is usually performed with a 131 I dose of 30 mCi. In Italy, this dose must be followed by a 24-h protected hospitalization, with increase in the waiting lists. In contrast, a 15 mCi dose can be given without hospitalization and with lower costs. Here, we investigated whether a lower dose of radioiodine can be used to ablate thyroid remnants in patients with GO, after thyroidectomy., Methods: The study was performed in two small groups of consecutive thyroidectomized patients (six patients per group) with Graves' hyperthyroidism and GO. Patients underwent ablation with either 15 or 30 mCi of 131 I following treatment with recombinant human TSH (rhTSH). The primary outcome was rhTSH-stimulated serum thyroglobulin (Tg) at 6 months. The secondary outcome was baseline Tg at 6 months., Results: Baseline Tg and rhTSH-stimulated Tg after at 6 months did not differ between two groups, suggesting a similar extent of ablation. rhTSH-stimulated Tg was reduced significantly compared with rhTSH-stimulated Tg at ablation in both groups. GO outcome following treatment with intravenous glucocorticoids did not differ between the two groups., Conclusions: Our findings may provide a preliminary basis for the use of a 15 mCi dose of radioiodine upon rhTSH stimulation in thyroidectomized patients with Graves' hyperthyroidism and GO.

The subclass distribution of thyroglobulin autoantibodies (TgAb) is debated, whereas their epitope pattern is restricted. Radioidine ((131)I) treatment for Graves' disease (GD) induces a rise in TgAb levels, but it is unknown whether it modifies subclass distribution and epitope pattern of TgAb as well. We collected sera from GD patients before (131) I treatment and 3 and 6 months thereafter. We measured total TgAb, TgAb light chains and TgAb subclasses by enzyme-linked immunosorbent assay (ELISA) in 25 patients. We characterized the TgAb epitope pattern in 30 patients by inhibiting their binding to (125-) (I) Tg by a pool of four TgAb-Fab (recognizing Tg epitope regions A, B, C and D) and to Tg in ELISA by each TgAb-Fab. Total TgAb immunoglobulin (Ig)G rose significantly (P = 0.024). TgAb κ chains did not change (P = 0.052), whereas TgAb λ chains increased significantly (P = 0.001) and persistently. We observed a significant rise in IgG1 and IgG3 levels after (131)I (P = 0.008 and P = 0.006, respectively), while IgG2 and IgG4 levels did not change. The rise of IgG1 was persistent, that of IgG3 transient. The levels of inhibition of TgAb binding to Tg by the TgAb-Fab pool were comparable. A slight, non-significant reduction of the inhibition by the immune-dominant TgAb-Fab A was observed 3 and 6 months after (131)I. We conclude that (131)I treatment for GD increases the levels of the complement-activating IgG1 and IgG3 subclasses and does not influence significantly the epitope pattern of TgAb. In autoimmune thyroid disease subclass distribution of autoantibodies is dynamic in spite of a stable epitope pattern., (© 2014 British Society for Immunology.)

Background: No long-term follow-up data are available for differentiated thyroid carcinoma (DTC) patients prepared with either exogenous or endogenous TSH and treated with low-activity (1.1 GBq [30 mCi]) radioiodine (¹³¹I)., Aim: The aim of this study was to evaluate the 10-year follow-up of DTC patients who underwent remnant ablation with 1.1 GBq ¹³¹I after l-T4 withdrawal, recombinant human TSH (rhTSH) administration, or both., Patients: A total of 159 DTC patients treated with total thyroidectomy and 1.1 GBq (30 mCi) of ¹³¹I for remnant ablation and stimulated with rhTSH and/or endogenous TSH were separated into ablated (n = 115) and not ablated (n = 44) patients and prospectively followed-up for at least 10 years. In addition, we evaluated several features that could correlate with the final status of patients., Results: During the follow-up, 4 of 115 (3.5%) ablated patients showed a recurrence and 1 was successfully cured. Among not ablated patients, 16 of 44 (36.4%) had a persistent disease. At the end of the 10-year follow-up, 140 of 159 (88.1%) patients were disease-free, whereas 19 of 159 (11.9%) remained affected. No correlation was found with the type of TSH stimulation, and no other clinical and pathological features showed any correlation with the final status. However, low levels of stimulated serum thyroglobulin (<5.4 ng/mL) at first control after remnant ablation identified a subgroup of not ablated patients who became spontaneously cured., Conclusions: Long-term outcomes are similar in DTC patients treated with 1.1 GBq (30 mCi) ¹³¹I and prepared either with rhTSH or endogenous TSH. It is of interest that serum thyroglobulin at first control after ablation can have a prognostic role.

Background: The most important side effect of radioiodine ((131)I) therapy is sialoadenitis and xerostomy., Aim: To evaluate by ultrasound (US) parotid and submandibular glands after (131)I therapy for differentiated thyroid cancer (DTC)., Patients: Seventy-six subjects thyroidectomized for DTC submitted to salivary glands US examination. Forty-three of them had been previously treated with (131)I: 22 with 1.11 GBq (30 mCi) for remnant ablation, and 21 with higher doses [up to 44.4 GBq (1200 mCi)] for metastases. Thirty-three subjects studied before (131)I therapy served as controls. Parotid and submandibular volume, homogeneity, and echogenicity were determined. (131)I-treated patients filled a questionnaire about sialoadenitis symptoms., Results: Parotid gland volume was significantly higher in treated patients (28.3±16.2 ml) than in untreated patients (20.7±10.4 ml, p=0.0154) and related to the time from last (131)I therapy. Three had parotid volume <1.5 ml and complained severe xerostomy. Submandibular gland volume was similar in treated (11.2±7.6 ml) and untreated patients (8.6±4.2 ml, p=0.0602). Homogeneity and echogenicity were similar in treated and untreated patients. Sialoadenitis symptoms were reported in 26% and were related to the (131)I cumulative dose. Symptoms were not related to gland volume. Hypoechogenicity and inhomogeneity of the parotids were more frequent in patients with salivary stickiness., Conclusion: Parotid, but not submandibular, volume is increased after (131)I treatment depending on the received activity and the time from irradiation but not on sialoadenitis symptoms. Xerostomy is associated to gland atrophy at US., (©2013, Editrice Kurtis)

Background: (131)I therapy is effective in reducing the volume of large nodular goiters (thyroid volume [TV]), mainly after stimulation with recombinant human thyrotropin (rhTSH). The amount of (131)I to be administered inversely depends on thyroid radioactive iodine uptake (RAIU). In patients with low RAIU, we evaluated the efficacy of (131)I treatment at lower doses with respect to those calculated on the basal RAIU, after rhTSH stimulation., Methods: Eighteen consecutive patients (17 women and 1 man, 49-83 years) with large nodular goiter were included in the study. At enrollment, 24th h RAIU, TSH, free thyroxine, free triiodothyronine, thyroglobulin antibodies, thyroid peroxidase antibodies, TSH receptors antibodies, urinary iodine, and TV were measured. RAIU was <40% in 11 patients (lower uptake group [LUG]) and >40% in 7 (higher uptake group [HUG]). RAIU difference in the two groups was significant (p < 0.0001). LUG patients were treated with rhTSH (0.03 mg i.m.) and RAIU was measured again after 24 hours. The administered amount of (131)I was aimed to give the thyroid a dose of 100 Gy, by the formula: (131)I activity = 370 MBq × TV (mL)/RAIU(%), taking into account RAIU value after rhTSH for LUG patients. Patients were re-evaluated 3 and 12 months after therapy., Results: At enrollment, LUG and HUG patients did not differ for TV, free thyroxine, free triiodothyronine, TSH, and urinary iodine. LUG patients were older than HUG patients (p = 0.027). In LUG, the uptake increased after rhTSH (42.8% [36%-47.5%] vs. 30% [23.4%-31.6%], p = 0.0044). The (131)I activity was 1073 MBq (740-1103 MBq) in LUG and 851 MBq (677-918 MBq) in HUG (p = 0.22, NS), vs. 1300 MBq (1077-2150 MBq) in LUG, based on RAIU before rhTSH. At 3 and 12 months after radioiodine, TV was reduced to 74% [59%-84%] and 53% [42%-72%] in LUG and 75% [70%-77%] and 65% [54%-74%] in HUG, respectively. The reduction was significant with respect to the basal, both at 3 and 12 months, but not different between the two groups., Conclusions: One single dose of 0.03 mg of rhTSH increased the thyroid RAIU by 40% in patients with nodular goiter and low basal uptake. This allowed a mean reduction of 36% (26%-42%) in the administered (131)I activity without loss of effectiveness. In patients with low RAIU, rhTSH pre-treatment may optimize (131)I therapy.