分化型甲状腺癌术后首次131I清甲效果影响因素的分析

目的 探讨分化型甲状腺癌（DTC）患者术后首次行131I清甲治疗疗效的影响因素。 方法 回顾性分析2013年4月至2022年3月于河北医科大学第四医院行DTC全切或近全切术后首次行131I 治疗的159例患者的临床资料,其中男性51例、女性108例,年龄24~78（46.5±11.9）岁。将患者按首次行131I治疗的剂量（2.96 GBq、3.70 GBq和5.55~7.40 GBq）分为3组进行研究。按清甲成功的判断标准,即131I 治疗后（4±1）个月131I诊断性全身显像示甲状腺床无放射性浓聚,分析患者的性别、年龄、手术方式、131I治疗前血清甲状腺球蛋白（Tg）水平及促甲状腺激素（TSH）水平、131I治疗距离手术的时间、131I治疗剂量对清甲效果的影响。计数资料的组间比较采用χ2检验。 结果 159例DTC患者首次行131I清甲的成功率为70.4%（112/159）。2.96 GBq组的首次131I清甲成功率为58.3%（21/36）,3.70 GBq组为69.2%（63/91）,5.55~7.40 GBq组为87.5%（28/32）,3组间的差异有统计学意义(χ2=7.071,P<0.05) 。手术方式为全切的DTC患者的清甲成功率为74.2%（95/128）,高于近全切患者的54.8%（17/31）,且差异有统计学意义（χ2=4.502,P<0.05）。治疗前TSH水平≥30 mU/L患者清甲成功率为73.9%（99/134）,高于治疗前TSH水平<30 mU/L患者的52.0%（13/25）,且差异有统计学意义（χ2=4.844,P<0.05）。患者在性别、年龄、131I治疗前血清Tg水平以及131I治疗距离手术的时间之间的差异均无统计学意义（χ2=0.311~3.073,均P>0.05）。 结论 131I治疗剂量、手术方式、131I治疗前TSH水平是影响DTC全切或近全切患者清甲成功率的因素。     

131I治疗分化型甲状腺癌术后患者疗效影响因素研究

目的 探讨影响分化型甲状腺癌（DTC）患者术后首次131I清除残留甲状腺组织（简称清甲）疗效和多次131I治疗转移灶（清灶）疗效的因素。方法回顾性分析首次接受大剂量清甲治疗的患者46例（分为成功组与未成功组）资料、多次清灶治疗的患者40例（分为临床缓解组和未缓解组）资料,对数据进行t检验、t’检验、X^2检验或Fisher确切概率法筛选影响因素,并做Logistic回归分析。结果用单因素分析筛选出手术方式、残余甲状腺质量、促甲状腺激素（TSH）水平、手术至清甲治疗时间和存在转移灶是影响清甲效果的因素（X2=5．804、t’=-5．258、t=7．376、X^2=8．867、X2=8．615,P均〈0．05）。Logistic回归分析得到的清甲成功的拟合方程为Y=3．766—0．947x,（残余甲状腺质量）-3．149x：（淋巴结转移）-3．373x,（远处转移）。对临床缓解率行单因素分析显示：甲状腺乳头状癌显著高于甲状腺滤泡状癌,仅有淋巴转移灶显著高于有远处转移灶,甲状腺全切显著高于其他手术方式（Fisher确切概率法,X。=7．278,P〈0．05）;首次131I治疗前,临床缓解组的TSH水平明显高于未缓解组,甲状腺球蛋白（Tg）水平明显低于未缓解组（t=4．489、t=-4．906,P均〈0．01）。Logistic回归分析得到清灶成功拟合方程为：Y=-0．363＋0．065x4（TSH水平）-0．250x5（Tg水平）。结论DTC患者首次清甲疗效的影响因素有手术方式、残余甲状腺质量、TSH、手术至清甲治疗时间和有无转移灶;其中残留甲状腺组织少、无淋巴结转移和无远处转移是提高成功率的关键因素。DTC患者清灶疗效的影响因素包括病理类型、手术方式、转移灶的部位、TSH和Tg;其中首次131I治疗前有较高水平的TSH和较低水平的强是提搞缓解率的关键因素。     

影响分化型甲状腺癌术后^131I清甲治疗疗效的因素分析

目的回顾性分析分化型甲状腺癌（DTC）患者术后残余甲状腺组织^131I清除治疗疗效的影响因素。方法对80例DTC术后首次接受^131I清除甲状腺残余组织（简称清甲）治疗的临床资料进行回顾性分析。以小剂量^131I全身显像的方法作为^131I清甲疗效的判断依据,显像中甲状腺床位置未见放射性浓聚视为清甲成功。分别采用,检验和Binary Logistic多因素回归分析的方法,研究患者性别、年龄（〈45岁和≥45岁）、病理类型（乳头状癌和滤泡状癌）、甲状腺外有无转移、残余甲状腺质量（少、中、多）、24h甲状腺吸碘率（〈10％、10％～20％、〉20％）、血清甲状腺球蛋白（Tg,阴性和阳性）和促甲状腺激素（TSH,〈30、30～60、〉60mU／L）水平及^131I剂量（〈1850MBq、1850—3700MBq、〉3700MBq）对^131I清甲疗效的影响。结果80例DTC术后患者,一次^131I治疗成功清甲为58例,有效率为72．5％。经,检验,24h甲状腺吸碘率、残余甲状腺质量及^131I剂量3项变量对^131I清甲治疗的疗效产生影响,各组内疗效比较差异有统计学意义（x^2=8．892,9．528,15．085,P=0．012,0．009,0．001）;而性别、年龄、病理类型、甲状腺外有无转移、血清Tg和TSH水平对^131I清甲治疗的疗效影响不显著,各组内疗效比较差异无统计学意义（x^2=0．486,0．051,0．322,0．010,0．006,2．575,P均〉0．05）。经Binary Logistic多因素回归分析,残余甲状腺质量（X1）和^131I剂量（X2）2项变量入选最终方程P=e^（-0.865-0.868X1＋1.677X2）/[1-e^（-0.865-0.868X1＋1.677X2）],Wald值分别为3．752和9．130,P值分别为0．049和0．003。结论DTC术后^131I清甲治疗的疗效主要取决于^131I治疗剂量和残余甲状腺的质量,与患者性别、年龄、病理类型、甲状腺外有无转移、血清Tg和TSH水平、甲状腺吸碘率无关。     

分化型甲状腺癌术后^131I清甲治疗方法的相关问题

分化型甲状腺癌（DTC）是最常见的甲状腺恶性肿瘤,其中包括乳头状甲状腺癌、滤泡状甲状腺癌和混合型甲状腺癌。治疗方法有手术治疗、^131I治疗和内分泌治疗。其中^131I治疗是甲状腺癌重要的治疗环节或步骤。随着对DTC术后^131I治疗方案的不断研究与探索,在重组人促甲状腺激素辅助,^131I清甲的应用、^131I清除大量残留的甲状腺叶组织、^131I清甲治疗碘剂量的选择等方面的认识与实践也不断更新。该文就以上几个清甲治疗方法的研究进行综述。     

甲状腺癌术后患者纵隔浓聚131I的临床分析

目的 探讨分化型甲状腺癌(DTC)手术及131I治疗后患者全身扫描(RxWBS)示纵隔浓聚131I的影像学特征.方法 收集1998-2004年收治的331例DTC术后患者共1183次131I治疗后5～7 d的RxWBS图像,所有患者至少接受2次131I治疗,结合甲状腺球蛋白(Tg)测定、其他影像学检查及临床随访结果分析纵隔浓聚131I的影像学特征及原因.结果 331例患者中最终诊断为纵隔浓聚131I者共34例,其RxWBS主要表现为纵隔点状、团块状、哑铃状或弥漫性放射性浓聚灶.其中甲状腺癌转移者21例,残留甲状腺组织8例,其余5例胸腺摄取131I患者年龄均＜45岁.结论 DTC术后患者纵隔浓聚131I可归因于甲状腺癌转移灶、甲状腺组织及胸腺摄取等.胸腺摄取131I是45岁以下甲状腺癌术后患者RxWBS假阳性的重要原因之一,血清Tg测定及131I SPECT/CT、CT增强扫描、MRI等有助于明确诊断.     

甲状腺乳头状癌术后刺激状态Tg预测131Ⅰ清甲治疗后Tg水平的价值

目的 探讨甲状腺乳头状癌患者术后刺激状态甲状腺球蛋白(Tg)水平预测131Ⅰ清除术后残留甲状腺组织(简称清甲)治疗后Tg水平的价值.方法 甲状腺乳头状癌患者138例,其中男28例,女110例,年龄6～70岁,平均39.4岁.所有患者均已行甲状腺全切或近全切除术,其中102例同时进行了颈部淋巴结清扫术,均经病理学检查确诊,于术后3～4周行131Ⅰ清甲治疗.131Ⅰ清甲治疗前后定期复查血清FT3、FT4、促甲状腺激素(TSH)、Tg抗体(TgAh)和Tg水平.采用SPSS 13.0软件行相关分析和两样本均数差异的t检验.结果 甲状腺切除术后和清甲治疗后刺激状态血清Tg水平呈明显正相关(r=0.960,P<0.01),清甲治疗后Tg阳性组和阴性组患者术后Tg水平分别为(199.8±327.7)μg/L、(3.5±5.6)μg/L,两组之间差异有统计学意义(t=5.567,P<0.01).76%(78例)患者有颈部淋巴结转移,41%(446枚)切除的淋巴结为阳性.颈部淋巴结转移数与术后及清甲治疗后刺激状态Tg水平呈明显正相关(r=0.697,0.633,P均<0.01).结论 甲状腺乳头状癌术后刺激状态Tg可有效预测131Ⅰ清甲治疗后Tg水平,甲状腺全切或近全切除术结合颈部淋巴结清扫术能有效降低清甲治疗后Tg阳性率.     

131I全身显像及血清甲状腺球蛋白测定在分化型甲状腺癌治疗随访中的作用

目的 评价131I全身显像联合血清甲状腺球蛋白(Tg)测定在分化型甲状腺癌(DTC)131I治疗随访中的临床应用价值。 方法 153例经手术病理确诊为DTC的患者,均在术后接受了1次以上的131I治疗,每次剂量为1.85~9.25 GBq,131I治疗前测定血清Tg,治疗5 d后进行131I全身显像。 结果 153例行131I治疗的DTC患者共行血清Tg和131I全身显像检查各为262次,其中55.6%(85/153)的患者的血清Tg水平与131I全身显像均异常,13.7%(21/153)的患者两者均为正常,30.7%(47/153)的患者两者结果不一致,不一致的47例患者经其他影像学检查证实19例131I全身显像异常的患者中有13例异常,28例血清Tg异常的患者中有25例异常。血清Tg诊断DTC转移的灵敏度和特异度分别为89%(110/123)和90%(27/30),而131I全身显像的灵敏度和特异度分别为79.6%(98/123)和80%(24/30)。 结论 DTC手术及131I治疗后,常规进行血清Tg测定和131I全身显像检查,对术后判定复发转移灶及制定最佳131I诊疗计划、评价131I疗效具有重要的临床应用价值。     

非高危分化型甲状腺癌低剂量和高剂量131I清甲疗效的分析

目的 研究应用低剂量（1.11 GBq）和高剂量（3.70 GBq）放射性131I清除非高危分化型甲状腺癌（DTC）术后残留甲状腺组织的疗效。 方法 回顾性分析行131I清甲治疗的63例非高危DTC患者的临床资料,采用Binary Logistic回归分析年龄、首次手术距清甲的时间间隔、甲状腺24 h摄碘率、血清TSH水平和清甲剂量对清甲疗效的影响;27例患者给予低剂量、36例患者给予高剂量的131I清甲治疗,采用Pearsonχ2检验分析低剂量和高剂量131I清甲疗效的差异,P < 0.05表示差异有统计学意义。 结果 63例非高危DTC患者中,清甲成功者46例（73.02%,46/63）、未成功者17例（26.98%,17/63）;Binary Logistic回归分析显示,131I清甲剂量是清甲成功与否的主要影响因素（Wald=6.42,P=0.011）;27例给予低剂量131I清甲患者中有15例清甲成功,36例给予高剂量131I清甲者中31例清甲成功,Pearsonχ2检验结果表明,高剂量131I清甲成功率（86.11%,31/36）明显高于低剂量（55.56%,15/27）（χ2=7.311,P=0.007）。 结论 在临床实践中,当残余甲状腺组织较少时,对于非高危DTC患者可考虑采用高剂量131I清甲治疗,提高一次清甲成功率。     

不同剂量首次131I去除甲状腺术后残留组织疗效比较

目的 回顾分析343例DTC病例,比较不同剂量首次131I去除甲状腺术后残留组织(RRA)疗效,并分析影响疗效的因素.方法 343例DTC患者行甲状腺全切术或近全切术,术后经影像学检查无局部或远处转移.以首次131I剂量将343例患者分为3组:A组101例,剂量为1850 ～2220 MBq;B组103例,剂量为2590～2960 MBq;C组139例,剂量为3330～3700 MBq.RRA后随访6～12个月.判断RRA成功标准:(1)131I全身扫描甲状腺床未见放射性摄取;(2) TSH刺激状态的Tg＜10 μg/L.应用SPSS 15.0软件对数据进行x2检验和logistic回归分析.结果 (1)343例患者RRA成功率63％( 215/343);(2)A、B和C组成功率分别为59％( 60/101)、64％( 66/103)和64％(89/139),3组疗效差异无统计学意义(x2=0.657,P=0.720);(3)单因素分析:筛选出性别(P=0.030)、手术方式(P＜0.01)、手术次数(P=0.004)、治疗前TSH(P =0.019)、治疗前Tg水平(P＜0.01)为有关因素,剔除年龄(P=0.420)、病理类型(P =0.585)、淋巴结转移(P =0.858)、多灶(P=0.365)、TNM分期(P =0.388)和剂量(P=0.733)等无关因素,将有关因素进行logistic回归分析,手术方式(P＜0.01)和治疗前Tg水平(P＜0.O1)是影响RRA疗效的因素.结论 DTC患者甲状腺全切或近全切术后,小剂量1850 ～ 2220 MBq RRA与大剂量3330～ 3700 MBq RRA疗效相同.术式和治疗前Tg水平是影响RRA成功的重要因素.     

重组人促甲状腺激素在131I治疗分化型甲状腺癌中的价值

目的 评价重组人TSH (rhTSH)介导DTC 131I清除甲状腺残余组织(简称清甲)治疗的安全性及有效性.方法 回顾性分析144例甲状腺全切或次全切术后接受131I清甲治疗的DTC患者.rhTSH替代组(Ⅰ组)72例使用rhTSH 0.9mg,1次/d,连续2d肌内注射;甲状腺激素撤退组(Ⅱ组)72例停用甲状腺素药物4～6周,2组均给予3.7 GBq 131I进行清甲.观察2组FT3、FT4、TSH和Tg的变化,同时观察患者怕冷、体质量增加、腹胀、便秘、动作迟缓、皮肤干燥、眶周水肿、骨痛等反应;根据131I全身显像结果,评价2组患者的131I清甲治疗效果,显像示甲状腺床区无放射性摄取或摄取率＜1％为一次清甲完全.数据比较行x2检验或t检验.结果 2组131I治疗前血清TSH水平均升高,Ⅰ组TSH明显高于Ⅱ组[(141.26±27.30)与(70.57±51.13) mU/L,t=2.435,P＜0.05],且Ⅰ组患者血清FT3、FT4水平无明显变化;2组131I治疗前血清Tg均升高.Ⅱ组患者发生不良反应统计:怕冷80.56％(58/72),体质量增加86.11％(62/72),便秘15.28％ (11/72),动作迟缓22.22％(16/72),皮肤干燥56.94％(41/72),骨痛2.78％ (2/72),无眼眶周围水肿者.Ⅰ组治疗安全性高,主要不良反应为:头晕恶心(2.78％,2/72),骨骼疼痛(2.78％,2/72),短暂性心动过速(1.39％,1/72).131I全身显像评价患者一次清甲完全率,Ⅰ组达70.83％ (51/72),Ⅱ组达66.67％(48/72),二者差异无统计学意义(x2 =0.58,P ＞0.05).结论 使用rhTSH能有效完成DTC131I治疗前准备,提高患者的生活质量,有利于残余甲状腺组织的清除.     

Radioiodine-131 in differentiated thyroid cancer: a retrospective analysis of an uptake-related ablation strategy

In our hospital, a 24-h radioiodine-131 (¹³¹I) uptake-related ablation strategy is used in patients with differentiated thyroid cancer to destroy thyroid remnants after primary surgery. In this strategy, low doses of ¹³¹I are used, but data in the literature on its efficacy are conflicting. Therefore, we performed the present study to evaluate the clinical outcome of this ablation strategy. In this study, patients (n=235) were selected who underwent thyroidectomy for differentiated thyroid cancer, followed by an ablative dose of ¹³¹I. Approximately 6 months after ablation, treatment efficacy was evaluated using radioiodine scintigraphy and thyroglobulin (Tg) measurements. Successful ablation was defined as the absence of radioiodine uptake in the neck region (criterion 1). Tg values were determined 3–12 months after ablation (criterion 2). Based on criterion 1, unsuccessful ablation was found in 43.0% of cases. Pre-treatment uptake values were statistically significantly lower (P=0.003) in successfully ablated patients (mean 5.4%) than in unsuccessfully ablated patients (mean 8.2%). Based on criterion 2, unsuccessful ablation was found in 52.4% of patients. The uptake-related ablation strategy, using low doses of ¹³¹I, shows a relatively high treatment failure rate. Based on these results it is suggested that a lower ablation failure rate could be achieved by applying higher ¹³¹I doses in the ablation of thyroid remnants in differentiated thyroid carcinoma patients. In the case of lymph node metastases a further dose adjustment may be advisable.     

甲状腺癌术后131I首次清除剩余甲状腺疗效分析

目的　观察不同年龄、性别、病理类型、手术方式、术后13 1I治疗时间、13 1I剂量、TSH水平以及剩余甲状腺外转移灶是否同时摄碘等因素对分化型甲状腺癌术后患者首次13 1I清除剩余甲状腺的影响。方法　分化型甲状腺癌术后患者 85例 ,手术治疗后 ,口服13 1I 1.11～ 5 .5 5GBq进行首次13 1I治疗 ,3～ 6个月后随访 ,以颈部剩余甲状腺显像与周围本底相比未见摄碘为成功清除的标准。结果85例中成功者 5 8例 ,成功率 6 8.2 %。不同的13 1I剂量、手术方式、术后首次治疗时间、TSH水平的变化以及剩余甲状腺外转移灶是否同时摄碘分别与成功率有一定关系 ;其中术后首次治疗时间与成功率之间呈负相关 (r=- 1.10 84,r0 .0 1( 3 ) =0 .95 9,P <0 .0 1)。不同年龄、性别及病理类型与成功率之间无明显关系。结论　适当的13 1I剂量、甲状腺全切手术、术后首次13 1I治疗时间 3个月以内、5 0mU/L以上的TSH水平以及仅有剩余甲状腺摄碘的分化型甲状腺癌术后患者疗效较好。疗效与患者的年龄、性别及病理类型无关     

Post-surgical ablation of thyroid remnants with high-dose (131)I in patients with differentiated thyroid carcinoma

The aims of this study were to evaluate the efficacy of an empirically determined "fixed" high ablative dose of radioiodine ((131)I) therapy and to determine the utility of ultrasonography (US) in dose determination. A retrospective analysis was performed of 242 thyroid cancer cases treated with "fixed" high-dose (131)I for ablation of thyroid remnants without a pre-ablative (131)I diagnostic scintigraphy or radioiodine uptake study. Treatment doses ranged from 1850 MBq (50 mCi) to 7.4 GBq (200 mCi). The selection of the treatment dose was based on the surgical and pathological findings as well as the remnant thyroid volume calculated by US. A successful ablation was defined as the absence of activity in the thyroid bed on subsequent imaging studies. Successful ablation was obtained in 218 of the 242 patients (90%). In 162 of the 218 patients (74.3%), successful ablation was achieved after a single (131)I treatment. The remnant thyroid volume calculated by US was significantly different (P=0.04) between those who were successfully ablated and those who were not. The total (131)I dose needed for successful ablation was significantly higher in males (P=0.003). Patients with higher post-operative thyroglobulin (Tgb) levels and patients with a higher stage of disease required higher doses (P=0.036 and P=0.021 respectively). Serum Tgb levels were under 10 ng.ml(-1) in 220 of the 242 patients (90%) following radioiodine ablation while not receiving L-thyroxine suppression. Nineteen patients (7.8%) showed metastases on post-therapy scan and successful treatment was achieved in 11 of 19 (57.8%). Four of the 19 patients with distant metastases (revealed on post-treatment scan) were found to have been given a treatment dose of less than 200 mCi based on the proposed empirical approach. These results indicate that "fixed" high-dose (131)I treatment is clinically feasible with an acceptable dose underestimation rate, and the utilization of US in the determination of the thyroid remnant volume provides more accurate and reproducible results.     

Differentiated thyroid cancer: radioiodine following lobectomy - a clinical feasibility study

The surgical management of differentiated thyroid cancer remains controversial. Total thyroidectomy has been associated with higher rates of post-operative morbidity than more conservative surgery, but radioiodine ablation of residual thyroid tissue is considered to be particularly difficult after lobectomy. The purpose of this retrospective study was to assess the feasibility of 131I ablation after lobectomy, compared with total thyroidectomy, in patients who had undergone surgery for differentiated thyroid carcinoma. A retrospective analysis was performed of 225 post-surgical thyroid cancer patients treated with 3500 MBq 131I for the ablation of thyroid remnants. One hundred and sixty-five patients (73%) had previously undergone total thyroidectomy, whilst 60 patients (27%) had been treated by lobectomy. All patients underwent diagnostic scintigraphy, with 40 MBq 131I, 2 days prior to ablative therapy and at 3 months post-ablation. The median pre-ablative 131I neck uptake values were 3.3% and 20.1% in patients treated by total thyroidectomy and lobectomy, respectively (P < 0.001). Pre-ablation neck uptake correlated strongly with the whole-body 131I burden 2 days after 131I therapy (P < 0.001), and the biological half-life of the radioiodine was markedly longer after lobectomy than after total thyroidectomy. Ninety-eight per cent of patients treated by total thyroidectomy were successfully ablated by one 131I treatment, compared with 90% after lobectomy (P < 0.05). There were no significant differences in 131I neck uptake or serum thyroglobulin levels between the two patient groups at 3 months post-ablation. These data show that high rates of thyroid ablation can be achieved with a single fixed dose of 131I after thyroid lobectomy. The use of this surgical procedure may result in a longer period of patient isolation than that required after total thyroidectomy. However, the clear correlation between pre-ablation neck uptake and 131I burden at 2 days post-therapy enables effective treatment scheduling, so making lobectomy followed by 131I ablation a practical option for the management of differentiated thyroid cancer.     

Fixed dosage of 131I for remnant ablation in patients with differentiated thyroid carcinoma without pre-ablative diagnostic 131I scintigraphy

Differentiated thyroid cancer is treated by (near) total thyroidectomy followed by radioiodine (131I) ablation of the residual active tissue in the thyroid bed. Controversy remains concerning the use and the dose of pre-ablative diagnostic 131I scintigraphy. This study was designed to assess the efficacy of thyroid ablation by high-dose 131I without pre-ablative diagnostic 131I scintigraphy. Ninety-three patients were treated with (near) total thyroidectomy and with a high ablative dose of 131I (3700-7400 MBq). A preablative 131I diagnostic scintigram was not performed. To assess the efficacy of the treatment, all patients were studied with a diagnostic 131I scintigram and with thyroglobulin plasma assays 1 year later after withdrawal of L-thyroxine for 4-6 weeks. The main criterion for a successful ablation was the absence of thyroid bed activity. An additional criterion was a thyroglobulin value of <10 microg x l(-1). Successful ablation according to the main criterion was obtained in 88% of patients. Forty patients (43%) showed no neck uptake and had undetectable serum thyroglobulin. Twenty-two patients (25%) had serum thyroglobulin concentrations between 1 and 10 microg x l(-1). Twenty-six patients (27%) had thyroglobulin >10 microg x l(-1), 19 patients showing residual thyroid uptake or metastatic lesions. We conclude that high-dose radioiodine ablation without prior diagnostic scintigraphy results in a high rate of successful ablation, preventing repeat 131I treatment.     

Serum thyroglobulin, a monitor of differentiated thyroid carcinoma in patients receiving thyroid hormone suppression therapy: concise communication

Serum thyroglobulin levels were obtained in 86 patients who had undergone thyroidectomy and I-131 ablation for differentiated thyroid cancer, and who were receiving or had recently discontinued thyroid hormone suppression therapy. Excellent correlation was observed between serum thyroglobulin levels in patients receiving thyroid hormone suppression therapy and I-131 imaging studies. Serum thyroglobulin levels equal to or below 20 ng/ml indicate the absence of thyroid carcinoma, and values exceeding 60 ng/ml were indicative of active thyroid cancer but may include some patients without clinical evidence of disease. Intermediate serum thyroglobulin levels were observed in a small number of patients with postsurgical thyroid remnants or active disease. Serum thyroglobulin levels are of considerable value in monitoring the activity of thyroid cancer in patients who are receiving thyroid hormone suppression therapy.     

Radioiodine lobar ablation as an alternative to completion thyroidectomy in patients with differentiated thyroid cancer

This study seeks to evaluate the role of radioiodine in the ablation of the remaining thyroid lobe, following a histopathological diagnosis of minimally invasive follicular carcinoma or papillary carcinoma of > or =1.5 cm size in patients undergoing hemithyroidectomy. There were 93 patients (69 females and 24 males) with an average age of 37.3+/-12.5 years (range, 16-70 years) and a mean follow-up duration of 46 months. Sixty-six of the patients had papillary cancer and remaining 27 had follicular thyroid cancer. The mean 24 h radioiodine neck uptake at the first visit was 17.2+/-7.3% (4.4-34%). In view of the large amount of thyroid tissue to be ablated, which may produce radiation induced thyroiditis, low doses of radioiodine (15-60 mCi) were administered to the patients. The patients were evaluated 6 months after radioiodine therapy with a 131I whole-body scan and 48 h radioiodine neck uptake, and a thyroglobulin assay after 4-6 weeks of levothyroxine withdrawal. The thyroid lobe was completely ablated in 53 patients (56.9%) after one dose of I and the remaining patients had partial thyroid ablation, with the mean radioiodine neck uptake being reduced to 3.1+/-2.4%. The mean first dose of 131I was 31.8+/-11.7 mCi; the estimated mean absorbed dose was 251.3+/-149.3 Gy (range, 120-790 Gy). Around 30% patients, in each of whom a remnant thyroid lobe was ablated with a single dose of radioiodine, received < or =200 Gy. The cumulative ablation rate was 92.1% after two doses of 131I. Only seven patients needed a third dose of 131I. In our cohort, 15 patients (16.1%) complained of throat discomfort and neck pain. All of them were managed with mild analgesics except three patients who needed additional oral prednisolone for 7-10 days to overcome neck oedema. We conclude that, although completion thyroidectomy remains the standard treatment after hemithyroidectomy in cases of differentiated thyroid cancer, radioiodine ablation of an intact thyroid lobe is possible and it can be achieved with much smaller doses of radioiodine than previously believed. Lobar ablation is an attractive alternative to surgery for those who refuse to undergo completion thyroidectomy or had complications during initial surgery. However, the long-term outcome in this subset of patients remains to be determined.     

Unusual case of well-differentiated papillary thyroid carcinoma lacking thyroglobulin expression while still concentrating radioiodine

We present an unusual case of a well-differentiated papillary thyroid carcinoma with bilateral lung metastases. Despite undetectable serum thyroglobulin (Tg) on thyroid stimulating hormone (TSH) stimulation and no immunohistochemical evidence of Tg expression in the primary tumour, the patient showed significant uptake of radioiodine in both lungs. After five cycles of high dose radioiodine therapy, the patient went into complete remission and therefore had an excellent response to radioiodine treatment. This case is a rare exception to the rule of Tg production as a prerequisite for differentiated thyroid cancers to concentrate radioiodine.     

Sensitivity of 123I whole-body scan and thyroglobulin in the detection of metastases or recurrent differentiated thyroid cancer

Primary treatment of differentiated thyroid carcinoma consists of total thyroidectomy followed by ablation of thyroid tissue remnants and possible metastases by means of radioactive iodine. After complete destruction of remnants, metastases or recurrence can be detected by measurement of the serum thyroglobulin level as well as by radionuclide methods. Here we report on the sensitivity of diagnostic 123I scintigraphy and serum thyroglobulin measurement for tumour detection in patients with proven recurrence or metastases. Fifty-five patients who received their first high activity (1,850-5,550 MBq) of 123I therapy after total thyroidectomy and 131I ablation were included in the study. The thyroglobulin level was measured both during TSH-suppressive L-thyroxine therapy (Tg-on) and 4-6 weeks after L-thyroxine withdrawal (Tg-off, TSH>20 mU/l). Prior to treatment, whole-body scanning (WBS) was performed 24 h after the administration of 111-370 MBq 123I. The therapeutic activity of 1,850-5,550 MBq 131I was administered within 24 h after diagnostic scanning. The mean interval between 131I therapy and post-therapeutic WBS was 8.6 days (range 3-15 days). The sensitivity of WBS, Tg-on and Tg-off was 75%, 82% and 98%, respectively. The overall sensitivity of the combination of Tg-on with WBS and of Tg-off with WBS was 95% and 100%, respectively. In 12 out of 51 cases either Tg-off or Tg-on or both Tg-on and Tg-off levels were elevated while 123I-WBS was negative. More lesions were visible on the post-therapeutic 131I scan than on the corresponding diagnostic 123I scan (n=13). Tg values increased significantly (P<0.0001) after thyroid hormone withdrawal. Early treatment of distant metastases or tumour remnants of differentiated thyroid carcinoma is favoured and 131I treatment should also be considered in patients with a negative WBS but positive serum Tg level. The finding of a positive Tg-off level, which is clearly above the corresponding Tg-on value, is sufficient to make this decision. Additional diagnostic 123I WBS will not improve sensitivity.