用 131I治疗不能切除的分化型甲状腺癌转移性淋巴结

目的　探讨1 31 I治疗不能手术切除的分化型甲状腺癌转移性淋巴结 (LMDTC)的治疗剂量和疗效。方法　对 2 4例分化型甲状腺癌术后不能手术切除的 84个LMDTC ,在 7 4～ 16 6 5GBq范围内选择不同剂量1 31 I治疗。分别于治疗后 1、3、6和 12个月随访观察LMDTC的状况。对≥ 2cm的LMDTC ,1 31 I治疗后视其变化确定再手术切除时间。结果　 84个不能手术切除的分化型LMDTC ,1 31 I治疗后有 78个分别消除、缩小和再次手术切除 ,有效率为 92 9% (78 84个 )。对 37个≥ 2cm的LMDTC1 31 I治疗后结合再手术治疗 ,切除病灶 16个 ,再切除率占 4 3 2 % (16 37个 )。与单纯用1 31 I治疗 <2cm的LMDTC的结果比较 ,差异有极显著性 (P <0 0 1)。1 31 I剂量为 3 7～ 12 95GBq时 ,各剂量组对LMDTC的疗效差异无显著性 (P均 >0 0 5 )。结论　大剂量1 31 I治疗分化型LMDTC有较好的疗效。     

内照射剂量学指导131I治疗分化型甲状腺癌弥散性肺转移

目的 从内照射剂量学角度探讨如何确定治疗分化型甲状腺癌弥散性肺转移（DTC-DPM）的131I活度.方法 依据美国核医学会医用内照射剂量学委员会提出的内照射剂量计算方法（MIRD体系）,将131I治疗DTC-DPM服131I后48 h时滞留于患者体内的131I不超过2.96 GBq的限定（2.96 GBq法则）转变为服131I后48 h时肺组织剂量率限定（DRCLU·48h）.假设眼131I后48 h时沉积于肺的131I与滞留于全身的131I活度比（F48h）在0.6～0.9间,131I在肺及剩余组织的有效半衰期（TLL、TRB）分别为20～120 h和10～20 h,参照OLINDA（Organ Level Internal Dose Assessment）软件中不同参考人体数据,计算不同DTC-DPM患者的131Ⅰ最大安全治疗活度（Amax）.结果 依据MIRD体系和2.96 GBq法则,131I治疗DTC-DPM,DRCLU·48h应不超过46.4 mGy/h.按照不同的F48h、TLU及TRB,成年男性、成年女性、15岁和10岁DTC-DPM患者的Amax分别在6.77～81.36 GBq、5.29～56.20 GBq、5.08～55.19 GBq和3.87～40.52 GBq间.结论 内照射剂量学指导131I治疗DTC-DPM充分地考虑了131I在不同患者体内的代谢动力学差异,可在避免发生放射性肺炎、肺纤维化的前提下,调节131I用量.     

大剂量131I治疗312例分化型甲状腺癌转移灶的临床分析

目的：评价甲状腺癌（简称甲癌）转移灶患者多次大剂量^131I治疗疗效及其副作用。方法：①治疗方法：肺、骨转移乾每次口服^131I7.4GBq，淋巴结转移者每次口服^131I5.55GBq，2次治疗间隔4个月。②疗效判断：分治愈：为^131I显像阴性，血甲状腺球蛋白（Tg）降至正常水平；有效：血Tg转阴，^1321I显像仅见病灶缩小或减少或病灶吸^131I率下降；无效：血Tg高水平，^131I显像有新病灶出现或患者死亡。③副作用观察为对甲状旁腺功能及染色体畸变的影响。结果：①疗效：312例甲癌转移灶患者治愈35.9％（112例），有效60.2％（188例），无效3.8％（12例）。②副作用：8.6％的患者有甲状旁腺素（PTH）一过性下降，但无1例甲状旁腺减退症发生。治疗后外周淋巴细胞染色体出现多种畸变，部分患者的辐射耐受增强。结论：采用^131I多次大剂量治疗甲癌转移灶疗效佳，副作用小，不会发生甲状旁腺功能减退症等并发症。^131I治疗的适应证应扩大至手术病理检查发现淋巴结转移者。     

131 I治疗分化型甲状腺癌脑转移

目的：探讨131I治疗分化型甲状腺癌（DTC）脑转移的临床价值。方法：随访8例经131I治疗的DTC脑转移患者，通过临床症状，影像学检查及生存率分析，观察DTC脑转移131I治疗效果。结果：（1）131I一生存期2－35年，2001年底随访时均存活；（2）I期患者131I治疗5次（20．65GBq)，后CT示右小脑占位灶缩小，6次（23．61GBq)后CT示占位灶消失。（3）甲状腺双侧切除者，术后剩余甲状腺平均131I清除次数为2次，平均总清除剂量8．87GBq;单侧切除者，平均清除次数5．7次，平均总清除剂量29．98GBq，后者的清除次数和剂量均明显高于前者（P＜0．01）。（4）合并有肺和（或）骨转移灶仍见131I提取。结论：合并有肺和（或）骨转移的DTC脑转移者治疗难度增加，但术后131I治疗仍有效。     

Upper retropharyngeal node involvement in differentiated thyroid carcinoma demonstrated by 131I scintigraphy

We report four patients with papillary thyroid cancer who had upper retropharyngeal node involvement demonstrated by 131I scintigraphy. Three patients presented with a thyroid nodule and enlarged jugular nodes. Total thyroidectomy was performed with node dissection. Pathology demonstrated papillary carcinoma with several metastatic nodes. 131I scanning 4 weeks after surgery demonstrated increased uptake in an upper retropharyngeal node. In one patient, thyroidectomy had been performed 21 years previously. Increased thyroglobulin level led to 131I scanning, which showed focal retropharyngeal uptake. All four patients had asymmetrical uptake at mouth level with focal uptake close to the sagittal plane. A lateral projection showed focal uptake between the base of the skull and the mandibular angle, behind the region of the mouth and nose. CT in all cases and MRI in one case confirmed the presence of an enlarged node. The mass was removed surgically in two patients and pathology confirmed the papillary nature of the metastatic node. Two patients were treated by 131I. Focal uptake of 131I in the region of the mouth is ambiguous, since salivary uptake of 131I is a common finding on scintigraphy. In cases of asymmetrical uptake in the region of the mouth, a lateral projection of the head therefore allows the correct diagnosis.     

儿童和青少年分化型甲状腺癌的^131I治疗

儿童和青少年DTC发病率不高,但与成人DTC相比,具有一些鲜明的特征：发现时病灶体积较大,诊断时多出现颈部淋巴结或远处转移,肿瘤细胞NIS表达增高,治疗后复发率高,但总体存活率较高。术后^131I治疗是治疗儿童和青少年DTC的重要手段。目前^131I治疗主要采用以下3种剂量模式：不引起骨髓抑制的最大剂量,可去除病灶的特定剂量和固定剂量。     

维甲酸在^131I治疗分化型甲状腺癌中的应用

分化型甲状腺癌（DTC）细胞在进展过程中可发生失分化,以致于术后^131I治疗或甲状腺素替代疗效差或无效,成为目前DTC治疗的难题之一。维甲酸作为维生素A的生物活性代谢产物,在调控细胞生长、分化、凋亡等生命活动中起着重要的作用。研究表明,维甲酸能够诱导失分化的DTC细胞再分化,提高肿瘤组织对^131I的摄取能力,从而提高DTC治疗的疗效。     

Cystic lymph node metastases in papillary thyroid carcinoma

OBJECTIVE: The aim of this study was to illustrate and discuss the sonographic spectrum of surgically proven cystic nodal metastases from papillary thyroid carcinoma. By correlative evaluation of the sonographic imaging findings to gross pathology and histology, our purpose was to provide useful hints to differentiate cystic lymph node metastases from other benign cystic neck lesions such as branchial cysts. MATERIALS AND METHODS: Sonographic examinations of 74 patients (47 women, 27 men; mean age, 49 years) with 97 histologically confirmed cystic lymph nodes metastases from papillary thyroid carcinoma were included in the study. The anatomic relationship of the nodes relative to the primary tumor was recorded, and all cystic nodes were qualitatively categorized as either simple (purely cystic) or complex (thickened outer wall, internal nodules, internal septations, and calcifications). All imaging findings were compared with gross pathologic specimens. RESULTS: Most of the cystic metastases were ipsilateral to the primary tumor (87.8%) and located in the mid or lower jugular chain (73.2%). In 14.9% of all patients, cystic lymph node metastases were the initial manifestation of disease. Only 6.2% of all lymph node metastases were purely cystic (all of these occurred in patients less than 35 years old). Of the 91 complex metastases, a thickened outer wall was present in 35.2% of patients, internal nodules in 42.9%, and internal septations in 57.1%. No calcifications were seen in the 91 complex metastases, and two or more findings were seen in 23.1%. All sonographic findings were verified by surgery. CONCLUSION: In most of the patients, cystic lymph node metastases are characterized sonographically by the presence of a thickened outer wall, internal echoes, internal nodularity, and septations. However, in younger patients, the lymph nodes might appear purely cystic, thereby mimicking branchial cysts and thus requiring biopsy for final diagnosis and therapy planning.     

Detecting the sentinel lymph node in patients with differentiated thyroid carcinoma

The aim of this study was to evaluate sentinel lymph node mapping in patients with differentiated thyroid carcinoma. Nine patients with suspected thyroid carcinoma who were scheduled to undergo thyroidectomy underwent scintigraphic localization of sentinel lymph nodes (SLNs). On the day of surgery we injected 37 MBq technetium-99m nanocolloid intratumourally. Dynamic data up to 10 min followed by planar anterior and lateral oblique images up to 1 h after tracer administration were recorded. At surgery the primary tumour was excised first, then the SLNs were removed using a gamma probe. Four patients had papillary carcinoma, two follicular carcinoma, one an oncocytic tumour and two benign tumours. An SLN was identified in all four patients with papillary carcinoma. In the two patients with follicular carcinoma, SLN detection failed. Five patients had one radioactive node, one had three and one had four. In one patient, no SLN was visible with scintigraphic imaging but at surgery three SLNs could be clearly identified using the gamma probe after removal of the primary tumour. There were no false-negative findings. This initial study indicates that in patients with papillary thyroid carcinoma detection of the SLN is possible, whereas the technique failed in two patients with follicular carcinoma. A study on a larger patient sample is now warranted.     

131I治疗分化型甲状腺癌对甲状旁腺功能的短期影响

目的 探讨131I清除术后残留甲状腺组织(简称清甲)治疗对DTC患者在治疗后短期内甲状旁腺功能的影响.方法 DTC患者共73例,其中男15例,女58例,年龄20～70( 44.59±12.89)岁.分别于131I清甲治疗前1天及治疗后第5天检测患者血Ca2+及PTH水平,比较131I清甲前后患者的血清PTH变化.以性别、年龄及术后超声示甲状腺残留组织(简称残甲)情况分组,分析影响治疗后血清PTH下降的因素.使用SAS 8.0软件对治疗前后计量数据等行配对t检验及方差分析,对年龄组与残甲组间数据行x2检验.结果 131I清甲治疗前后所有患者血钙均在正常范围,均值分别为(2.24±0.93)和(2.23±0.84) mmol/L,差异无统计学意义(t=1.81,P＞0.05);治疗后DTC患者血清PTH为(27.19±11.58) ng/L,明显低于治疗前的(37.33±17.71)ng/L(t=6.76,P＜0.01),其中79.45％ (58/73)的患者PTH较治疗前下降,10.95％ (8/73) PTH值低于正常;但均未出现低钙血症.治疗前后不同性别组间血清PTH差异无统计学意义(t=1.06和1.83,P均＞0.05),但发生PTH降低例数比较有统计学意义(x2=4.37,P=0.036).不同年龄组及不同残甲组治疗前后血清PTH的变化差异均无统计学意义(F=0.58、0.61,0.46、0.76,P均＞0.05).结论 131I治疗可导致DTC患者短期内PTH水平降低,女性更为敏感,但一般不会引发低钙血症.这种变化与年龄及残甲组织多少无关.     

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.     

分化型甲状腺癌术后患者131I治疗的辐射剂量与防护

监测分化型甲状腺癌（DTC）患者术后131I治疗的辐射剂量并规范其辐射防护对DTC患者131I治疗后自身及周围人群的健康有重要意义.目前研究表明,131I治疗的DTC患者自身的辐射不良反应大多都能得到较有效地缓解和控制.只要能严格规范地遵守131I治疗DTC的辐射防护相关法规和建议,加强辐射剂量监测,并对患者、工作人员和患者家属进行适当的教育和指导,其对周围人群的辐射剂量都能达到和符合国际上的辐射防护规定.     

131I治疗分化型甲状腺癌转移灶中甲状腺球蛋白测定和131I-全身显像的意义

目的探讨分化型甲状腺癌转移灶治疗中131I-全身显像(131I-WBS)和甲状腺球蛋白(Tg)测定的意义。方法39例分化型甲状腺癌患者术后4～6周用131I行首次清除残余甲状腺治疗,3～6个月后重复治疗,治疗中131I-WBS和Tg测定同期完成。结果在首次清除残余甲状腺治疗时显像发现淋巴、肺及骨转移灶有11例,其余转移灶于重复治疗时发现。131I治疗分化型甲状腺癌转移灶,以淋巴转移效果最好,肺转移次之,骨转移最差。有8例患者(20.5%)Tg测定与131I-WBS不符。结论131I治疗分化型甲状腺癌转移灶效果好,患者存活率高;131I-WBS和Tg测定在分化型甲状腺癌随访中应联合应用,互相补充。     

^131I治疗分化型甲状腺癌骨转移的疗效评价和生存分析

目的评价^131I治疗DTC骨转移的疗效及影响因素,评估生存率及其影响因素。方法回顾分析经^131I治疗的106例DTC骨转移患者的临床资料,分别基于^131I治疗后血清Tg的变化、骨痛缓解情况和影像学变化评价^131I治疗疗效,并对影响^131I疗效的因素进行单因素分析;采用寿命表法评估DTC骨转移患者的^131I治疗后总生存率;采用Kaplan—Meier法对影响生存率的因素进行分析,应用Log-rank法比较各组间差异。结果经^131I治疗后血Tg显著下降者37例,有效率34．9％。骨转移伴疼痛的61例DTC经^131I治疗后疼痛明显缓解者39例,有效率63．9％。患者年龄、病理类型、是否合并其他非骨性远端转移等因素对^131I治疗后血Tg的变化有影响（x2=6．443,11．455和6．756,P均〈0．05）,但对^131I治疗后骨痛缓解的影响无统计学意义（x2=0,0,0．060,P均〉0．05）。^131I治疗后77．4％的患者骨转移灶无明显影像学变化。该组DTC骨转移患者5年和10年生存率分别为86．47％和57．90％;骨转移灶数目、是否合并其他远端脏器转移、^131I治疗前是否行手术治疗对患者的10年生存率影响差异有统计学意义（Log-rank值为4．05,5．98和4．22,P均〈0．05）;患者的性别、年龄、病理类型、是否以骨转移症状首诊等因素对10年生存率无明显影响（Log—rank值为0．01,1．56,2．59和0．04,P均〉0．05）。结论^131I治疗可使DTC骨转移患者血清Tg下降、骨痛缓解、病灶保持稳定或缩小,是治疗DTC骨转移的有效手段;单发病灶、单纯骨转移、手术＋^131I治疗患者预后较好。     

维甲酸在~(131)I治疗分化型甲状腺癌中的应用

分化型甲状腺癌(DTC)细胞在进展过程中可发生失分化,以致于术后~(131)I治疗或甲状腺素替代疗效差或无效,成为目前DTC治疗的难题之一.维甲酸作为维生素A的生物活性代谢产物,在调控细胞生长、分化、凋亡等生命活动中起着重要的作用.研究表明,维甲酸能够诱导失分化的DTC细胞再分化,提高肿瘤组织对~(131)I的摄取能力,从而提高DTC治疗的疗效.     

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。     

Iodine-131 treatment and high-resolution CT: results in patients with lung metastases from differentiated thyroid carcinoma

Between 1984 and 2002, pulmonary metastases were detected in 42 (4%) out of 1,023 patients with differentiated thyroid carcinoma (DTC) in our department. The age at diagnosis ranged from 6 to 77 years. Lung metastases were diagnosed by both increased thyroglobulin (Tg) levels and positive uptake of iodine-131 on scans, and/or positive radiological findings. The primary tumours were histologically classified as papillary (30 patients), follicular (nine patients) and poorly differentiated (two tall cell, one insular carcinoma). The duration of follow-up ranged from 24 to 228 months. The end-results of the ¹³¹I therapy were evaluated. The treatment of choice was ¹³¹I therapy of metastases after total thyroidectomy plus lymph node dissection (if lymph node metastases were present). Applied single and total ¹³¹I activities were 1.8–10.4 GBq and 5.5–43.7 GBq, respectively. Lung metastases were present at the time of diagnosis in 30 patients and developed during the follow-up period in the remaining 12. Twelve patients with extensive metastases died of thyroid carcinoma and another died due to secondary malignancy (malignant mesothelioma). Ten patients with lung metastases remain completely free of disease and are probably cured, while another seven were stable at the time of study. Three- and five-year survival rates were 86% (36/42) and 76% (32/42), respectively. To define the diagnostic value of high-resolution computed tomography (HRCT) and identify the distinctive features of lung metastases from DTC, 22 patients were further examined with HRCT within 2 weeks of the initial diagnosis of lung metastases and the results were compared with chest X-ray findings. HRCT detected metastases in 10 out of 14 patients with a normal chest X-ray and confirmed metastases in all patients with positive (n=5) and suspicious (n=3) chest X-ray. HRCT did not show any abnormalities in four patients with positive lung uptake on ¹³¹I whole-body images. Stage of disease, existence of distance metastases other than to the lung, and HRCT characteristics were significant prognostic variables. Lung metastases from DTC can be cured with ¹³¹I therapy in a considerable number of patients, especially when they are not associated with other distant metastases; they should therefore be treated at an early stage. HRCT clearly improved diagnostic ability in the evaluation of lung metastases compared with chest X-ray and should be the primary method when radiological correlation is needed. The main, and new, finding of the study is that HRCT not only improves diagnostic ability but is also of prognostic value.     

Percutaneous ethanol injection for treatment of cervical lymph node metastases in patients with papillary thyroid carcinoma

OBJECTIVE: The objective of this study was to evaluate the technique, efficacy, and side effects of percutaneous ethanol injection in patients with limited cervical nodal metastases from papillary thyroid carcinoma. SUBJECTS AND METHODS: Fourteen patients who had undergone thyroidectomy for papillary thyroid carcinoma presented with limited nodal metastases (one to five involved nodes) in the neck between May 1993 and April 2000. All patients had received previous iodine-131 ablative therapy with a mean total dose per patient of 7,548 MBq. Ten of the patients either were considered poor surgical candidates or preferred not to have surgery, and all were unresponsive to iodine-131 therapy. Each metastatic lymph node was treated with percutaneous ethanol injection, and patients received both clinical and sonographic follow-up. RESULTS: Twenty-nine metastatic lymph nodes in our 14 patients were injected. Mean sonographic follow-up was 18 months (range, from 2 months to 6 years 5 months). All treated lymph nodes decreased in volume from a mean of 492 mm(3) before percutaneous ethanol injection to a mean volume of 76 mm(3) at 1 year and 20 mm(3) at 2 years after treatment. Six nodes were re-treated 2-12 months after initial percutaneous ethanol injection because of persistent flow on color Doppler sonography (n = 4), stable size (n = 1), or increased size (n = 1). Two patients developed four new metastatic nodes during the follow-up period that were amenable to percutaneous ethanol injection. Two patients developed innumerable metastatic nodes that precluded retreatment with percutaneous ethanol injection. No major complications occurred. All patients experienced long-term local control of metastatic lymph nodes treated by percutaneous ethanol injection. In 12 of 14 patients, percutaneous ethanol injection was successful in controlling all known metastatic adenopathy. CONCLUSION: Sonographically guided percutaneous ethanol injection is a valuable treatment option for patients with limited cervical nodal metastases from papillary thyroid cancer who are not amenable to further surgical or radioiodine therapy.     

The early detection of metastatic differentiated thyroid cancer using 131I total body scan and treatment with 131I

With the purpose of achieving early detection and performing 131I therapy for metastatic lesions of differentiated thyroid cancer, we studied the clinical findings in 132 patients who underwent 131I total body scanning (131I TBS) between 1981 and 1990. Metastatic lesions were detected only by 131I TBS in 24 (18%) of the 132 patients. Of the 49 patients treated with 131I for metastases, 27 (55%) underwent total thyroidectomy and then had their metastatic lesions treated by 131I less than one year later. In the remaining 22 patients (45%), the metastatic lesions were treated with 131I from 1 to 31 years (mean: 8.4 years) after the initial thyroidectomy. We determined the optimal timing of 131I TBS following radical thyroidectomy to be 3-4 weeks by sequential measurement of the serum thyroid hormones, TSH, and Tg, and determination of the 123I uptake in residual or metastatic cancer of the neck after thyroidectomy. 131I TBS with simultaneous serum Tg determination were performed in 52 patients with metastases. Scans were positive in 43 of the 52 (83%) and the serum Tg level was greater than 10 ng/ml in 46 of the 52 (88%). Serum Tg was elevated in 9 patients with negative scans, while low Tg levels were found in 6 patients with positive scans. 131I therapy was effective in 49 of the 65 treated patients (75%), including 5 cures. Two patients worsened and 6 died. These 8 patients were all older than 56 years of age. Post-therapeutic 131I TBS demonstrated unsuspected metastatic lesions in 7 patients and had a higher detection rate for metastatic lesions than diagnostic 131I TBS. We conclude that 131I TBS with simultaneous Tg determination should be performed to detect metastatic lesions in all patients following positively total thyroidectomy for differentiated thyroid cancer, and that 131I treatment should be given when positive 131I uptake is detected in metastatic or residual cancer.