Thyroid-hormone concentrations after radioiodine therapy for hyperthyroidism

Fourteen hyperthyroid patients (11 men, three women), ages 28-66, were followed with serial measurements of serum thyroid hormone levels for 1 mo after therapy with I-131. Twelve patients had diffuse toxic goiters (25--70 g in size); two patients had multinodular glands (40--100 g). The patients were taking no antithyroid medications; ten patients were treated with propranolol. All patients received the equivalent of 5000 rad, except the two with multinodular glands, who received larger doses. There was no consistent pattern of serum T4 and T3 levels after the I-131 therapy. For the entire group, there was no significant increase of the mean serum hormone concentration. One group (three patients) had a mean T4 increase of 28% and a T3 increase of 91% above baseline at Days 10--11. Seven patients had minimal increases of hormone levels at Days 2--3, and a third group (four patients) had no increase of thyroid hormones after I-131 therapy. The patients with no rise in hormone concentrations had smaller goiters than the other groups. There was no correlation of the dose of radioactive iodine, or of the initial hormone concentration, with the rises or declines of T4 and T3 levels after I-131 therapy. Radioiodine therapy caused no significant increase of serum T4 and T3 concentrations in the majority of patients.     

Results of radioiodine (131/125I) therapy of hyperthyroidism.

One individually calculated dose of 131I was sufficient to control the hyperfunction in 75% of the patients with Graves' disease and 85% of the patients with autonomous adenoma. The cumulative myxedema risk 10 years after therapy was: 15% in the patients with Graves' disease and nearly zero in patients with autonomous adenoma. Early results of 125I therapy of Graves' disease are presented. Peculiar aspects of thyroid function after destructive therapy of Graves' disease are discussed.     

131I治疗甲亢中的临床护理

由于放射性核素^131I治疗甲状腺功能亢进症（简称甲亢）具有简便、经济、有效和安全的优点，越来越多的临床医师将其作为治疗甲亢的首选方法。系统化整体护理对安全和有效地开展^131I治疗甲亢有重要的临床意义，现将我们近年来对^131I治疗甲亢的护理体会介绍如下。     

Clinical outcome after standardized versus dosimetric radioiodine treatment of hyperthyroidism: an equivalence study

The aim of this study was to investigate the equivalence in outcome of standardized versus uptake-adjusted dosing of radioactive iodine (131I) for hyperthyroidism. We performed a 1-year follow-up study of two patient cohorts: 326 patients referred for 131I treatment of hyperthyroidism in Graves' disease (GD; n=216) or toxic multinodular goitre (TMG; n=110) in the period June 1995 to January 1998. Of these patients 128 were treated according to a standardized regimen, based on palpated thyroid volume and diagnosis, and 198 with a 131I uptake-adjusted dosimetric method. The incidence of hypothyroidism, euthyroidism or recurrence of disease was recorded. In Graves' disease hypothyroid outcome in the standardized versus adjusted method was 40.7% vs 44.6% (95% CI difference, -17.4 to +9.5%); it was 67.4% vs 70.8% (95% CI difference -15.9 to +9.3%) for all non-euthyroid outcomes. In TMG, due to wide confidence interval ranges a conclusion of equivalence could be made only for recurrence of hyperthyroidism (mean -3.2%, 95% CI, -13.8 to +7.5%). A simplified dosage method for 131I treatment of hyperthyroidism, which omits 131I uptake adjustment, may improve procedure efficiency and patient convenience, and leads to an equivalent outcome in GD and probable equivalent outcome in TMG.     

^131I辅以短期小剂量碳酸锂治疗Graves甲亢的研究

目的探讨碳酸锂在^131I治疗Graves甲亢中的辅助疗效。方法选取Graves甲亢患者100例,随机分为^131I治疗组和^131I＋碳酸锂治疗组,每组患者各50例,两组间的平均年龄差异无统计学意义。^131I＋碳酸锂治疗组服^131I前后15d内分别给予碳酸锂治疗（2次／d,每次0．25g）;^131I治疗前采用超声和触诊的方法估算甲状腺质量,两组甲状腺质量差异无统计学意义;两组患者均一次性服^131I口服液并于治疗后15、30、45d监测颈前放射性吸收剂量率;治疗前和治疗后30、45、90、180d分别检测血清游离三碘甲状腺原氨酸（fT3）、游离甲状腺素（fT4）和TSH水平,治疗后半年对其疗效进行评价。结果两组^131I治疗后颈前放射性吸收剂量率均随时间的推移逐渐降低,不同监测时段总体差异有统计学意义（H=132．46、132．47,P均〈0．01）;治疗后15、30、45d放射性吸收剂量率两两间的差异均有统计学意义（^131I组：t=88．51、113．70、59．42,P均〈0．01;^131I＋碳酸锂组：t=83．44、112．76、70．18,P均〈0．01）;但两组相同监测时段的放射性吸收剂量率比较,^131I＋碳酸锂组均明显高于^131I治疗组（t=8．81、15．18、10．10,P均〈0．01）。治疗前和治疗后不同时段,两组的血清TSH平均水平均低于正常参考值范围（0．55-4．78mlU／L）,总体差异无统计学意义（F=1．23,P〉0．05）。两组间治疗前和治疗后不同时段的血清几和几水平总体差异有统计学意义（F=9．65、22．45,P均〈0．01）：治疗前两组血清fT3、fT4水平的差异均无统计学意义;各组治疗后30d的血清几、几水平均明显高于同组治疗前（^131I组：tff3=5．23,tfT4=10．14;^131I＋碳酸锂组：tfT3=5．12,tfT4=9．98,P均〈0．01）,此后逐渐下降,治疗后90d基本恢复正常;两组治疗后同期iT3、fT4水平比较,仅治疗后30d ^131I＋碳酸锂治疗组明显低于^131I治疗组（t=8．22、19．18,P均〈0．01）,其余各期两组的fT3、fT4水平差异无统计学意义;^131I治疗后半年疗效评价,^131I治疗组与^131I＋碳酸锂治疗组的治愈率分别为72％（36／50）和76％（38／50）。两组疗效比较,差异无统计学意义（x^2=0．21,P〉0．05）。结论碳酸锂可延长^131I的有效半衰期、预防^131I治疗后一个月内血清甲状腺激素浓度反应性升高、加强甲状腺毒症的控制,对于^131I治疗前停服抗甲状腺药物、不能耐受或无效和有效半衰期短的患者,Graves甲亢辅以碳酸锂治疗有助于^131I治疗短期疗效的提高和避免^131I治疗后短期甲状腺毒症的恶化。本研究尚未观察到碳酸锂有助于提高Graves甲亢^131I治疗的远期治愈率。     

Changes in conjunctival cytology and tear function tests with radioiodine treatment for hyperthyroidism

Objectives

Radioiodine (RAI) is used in the treatment of hyperthyroidism and differentiated thyroid cancer. Radioiodine therapy is associated with dry eyes and some side effects are seen especially due to beta rays. In this study, the functional and cytological status of lacrimal glands after RAI therapy was evaluated.

Methods

Twenty-five patients with a mean age of 55.16 years with planned low-dose RAI therapy were evaluated. Just before and 6 months after the treatment, the lacrimal glands were evaluated with tear break-up time (BUT), Schirmer’s test, impression cytology and “Ocular Surface Disease Index (OSDI)” questionnaire.

Results

The mean value of Schirmer’s test was 16.20 ± 3.61 pre-treatment and 11.28 ± 4.39 post-treatment for the right eye, and 15.76 ± 3.27 and 10.60 ± 4.42 for the left eye, respectively. The mean value of Schirmer’s test decreased significantly post-treatment in both eyes (p = 0.0001). The BUT score also decreased significantly post-treatment (p = 0.001). The mean value of OSDI score was 27.5 ± 8.02 pre-treatment and 46.36 ± 10.27 post-treatment. The mean value of OSDI score increased post-treatment (p = 0.0001). The impression scores also increased post-treatment in both eyes (p = 0.0001).

Conclusion

Even low-dose (≤30 mci) RAI treatment affects lacrimal gland functions. Low-dose RAI causes a decrease in the value of Schirmer’s test and the BUT test, and an increase in the value of OSDI score and impression scores.     

Apoptosis: its pathophysiology and monitoring. The role of apoptosis in the radioiodine therapy of hyperthyroidism

The review aims to give an up to date understanding of the mechanisms of apoptosis (programmed cell death), the methods of detecting apoptosis, in particular with regard to imaging such changes non-invasively. Radioiodine (I-131) is a gamma and beta emitting radionuclide and is commonplace in the treatment of hyperthyroidism. I-131 therapy relies on the destruction of thyroid tissue by beta radiation, and such destruction is proposed to be partly as a result of apoptosis. The review undertakes to explore and provoke research into the mechanisms of thyroid cell destruction by I-131, and whether such changes are able to be detected or monitored. Current knowledge concerning apoptosis in the thyroid gland in diseased states (including cancer) are described. The clinical significance of monitoring and modifying apoptosis are emphasized. Furthermore, overt and late destruction of thyroid tissue following I-131 therapy requires elaboration, and the relevance of detecting and modifying thyroid cell apoptosis following I-131 are questioned.