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。     

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。     

甲状腺癌及其转移灶~(131)I治疗过程中外周血象变化

目的　观察甲状腺癌及其转移灶治疗过程中131I累积剂量对骨髓抑制的影响。　方法甲状腺癌术后患者 177例 ,随访时分别测其白细胞 (WBC)、红细胞 (RBC)、血红蛋白 (Hb)和血小板(PLT) ,观察不同性别、年龄、131I累积治疗剂量、肿瘤病理类型以及转移时外周血象的变化 ,同时进行方差分析和相关回归分析。结果　性别对WBC和PLT影响不大 (FW =0 .399和FP=0 .90 3 ,P均 >0 0 5 ) ,但女性RBC和Hb明显低于男性 (FR=2 5 .2 17和FH=30 .895 ,P均 <0 .0 1) ;年龄、肿瘤病理类型以及转移状况对血象变化的影响无统计学意义。各131I累积治疗剂量组血象均值都在正常范围内 ,但组间差异有显著性 ,而且血象的变化与131I累积治疗剂量间呈线性关系 ,随着131I累积治疗剂量的增加 ,血象呈降低趋势。结论　131I累积治疗剂量对骨髓抑制有一定的影响 ,其外围血象的变化与131I累积治疗剂量呈负相关。     

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。     

分化型甲状腺癌术后131I清甲效果的影响因素

利用131I清除甲状腺癌术后残留甲状腺组织(清甲)是分化型甲状腺癌(DTC)术后治疗中的重要步骤.清甲效果受诸多因素影响,包括口服131I的剂量、DTC的手术方式、术后甲状腺组织残留量、血清促甲状腺激素(TSH)与甲状腺球蛋白(Tg)水平、有无淋巴结及远处转移、手术距13I治疗时间的长短等.使用较大剂量131I进行清甲、采取甲状腺全切或近全切除术方式、131I治疗前较高水平的TSH,以及术后及时开始131I治疗等有助于提高清甲成功率.131I治疗前患者血清Tg水平偏高或存在转移灶,应适当加大131I治疗剂量.患者性别、年龄、病理类型等对清甲成功与否无明显影响.     

99TcmO4-全身显像联合颈胸SPECT/CT在DTC患者术后肺转移灶显影中的应用

目的探讨99TcmO₄-全身显像联合颈胸SPECT/CT在分化型甲状腺癌（DTC）术后肺转移灶检出中的应用。方法回顾性分析2013年1月至2016年1月收治的34例DTC肺转移患者在术后131I治疗前的99TcmO₄-全身显像联合颈胸SPECT/CT中肺转移灶的检出情况,计算99TcmO₄-全身显像联合颈胸SPECT/CT检出肺转移灶的灵敏度、阳性预测值,并评估其对治疗决策的影响。结果34例肺转移患者中,2例表现为阳性（放射性浓聚+结构异常）,10例表现为可疑阳性（仅有典型肺转移CT表现）,22例表现为可疑阴性,若将可疑阳性与阳性均视为阳性发现,则99TcmO₄-全身显像联合颈胸SPECT/CT发现肺转移灶的灵敏度为35.3%（12/34）,阳性预测值为100%（12/12）,11例患者在后续的131I治疗中增加了剂量。结论99TcmO₄-全身显像联合颈胸SPECT/CT能发现部分无99TcmO₄-浓聚的肺转移灶,提高了肺转移灶的检出率;指导临床调整131I治疗剂量,改善预后。     

甲状腺癌及其转移灶131 I治疗过程中外周血象变化

目的 甲状腺癌及其转移灶治疗过程中131I累积剂量对骨髓抑制的影响,方法甲状腺癌术后患者177例,随访时分别测其白细胞（WBC）,红细胞（RBC）,血红蛋白（Hb)和血小板（PLT）,观察不同性别,年龄,131I累积治疗剂量,肿瘤病理类型以及转移时外周血象的变化,同时进行方差分析和相关回归分析。结果 性别对WBC和PLT影响不大（FW＝0．399和FP＝0．903,P均＞0．05）,但女性RBC和Hb明显低于男性（Fn=25.217和FH=30.895,P均＜0．01）,年龄,肿瘤病理类型以及转移状况对血象变化的影响无统计学意义。各131I累积治疗剂蛳组血象均值都在正常范围内,但组间差异有显著性,而且血象的变化与131 I累积治疗剂量间呈线性关系,随着 131I累积治疗剂量的增加,血象呈降低趋势。结论 131 I累积治疗剂量对骨髓抑制有一定的影响,其外围血象的变化与131I累积治疗剂量呈负相关。     

分化型甲状腺癌肺转移灶早期显影与^131I疗效关系分析

目的探讨DTC肺转移患者首次应用^131I清除甲状腺组织（简称清甲）时肺转移灶显像与^131I治疗效果的关系,及影响肺转移灶早期显影的因素。方法回顾分析1997至2009年41例DTC肺转移患者清甲治疗时肺转移灶显影情况,评价^131I治疗DTC肺转移疗效。疗效评价分临床治愈、好转和无效。前两者为治疗有效。采用SPSS11．5软件,对有效率、有无远处转移、显像特点进行,检验及交叉分类2×2列联表关联分析。结果41例患者中8例为临床治愈,18例好转,有效率63％（26／41）,14例无效,1例患者死亡,无效率37％（15／41）。清甲治疗时肺部转移灶显影患者^131I治疗有效率76％（22／29）,随访和重复治疗中显影患者^131I治疗有效率为33％（4／12）,两者差异有统计学意义0,2=4．911,P=0．027）;肺转移灶^131I摄取呈弥漫性或局灶性,两者间有效率分别为67％（12／18）和61％（14／23）,差异无统计学意义（χ2=0．146,P=0．702）;肺外有远处转移者^131I治疗DTC肺转移灶有效率为22％（2／9）,无远处转移者有效率为75％（24／32）,差异有统计学意义（χ2=6．312,P=0．012）;83％（24／29）行甲状腺全切的患者在首次清甲治疗时即有肺转移灶显影,而行甲状腺部分切除患者中仅有42％（5／12）,甲状腺手术方式与肺转移灶早期显影有相关性（r=0．411,P〈0．05）;乳头状癌和滤泡状癌患者中首次清甲治疗时肺转移灶早期显影患者分别为72％（23／32）和6／9,病理分型和肺转移灶显影早晚无关（r=0．047,P〉0．05）。结论DTC肺转移患者清甲治疗时转移灶显影阳性、无肺外远处转移灶者的^131I疗效好。     

131Ⅰ显像及Tg值监测131Ⅰ治疗分化型甲状腺癌肺转移灶疗效的探讨

目的 探讨131I显像和Tg在监测131I治疗DTC肺转移患者疗效中的价值.方法 回顾性分析2007年6月至2011年8月收治的DTC肺转移患者50例,分别以131I显像、Tg、131I显像+Tg 3种方法监测及评价131I治疗DTC肺转移灶效果.比较131I显像肺转移灶呈弥漫性摄取和局灶性摄取患者治疗有效率的差异,计算有无肺外远处转移患者的治疗有效率.按治疗前及治疗中Tg水平将患者分为3组:＜ 100 μg/L、100 ～ 1000 μg/L和＞1000 μg/L组,比较3组治疗有效率差异.131I治疗前后Tg比较及不同组Tg间的比较采用秩和检验.独立二分类资料比较采用x2检验及Fisher确切概率法.结果 50例治疗前131I显像阴性2例,131I显像阳性48例.48例阳性患者中,治疗后11例显像阴性,24例病灶好转,有效率73％(35/48).肺转移灶呈131I弥漫性摄取与局灶性摄取者的有效率分别为69％(11/16)、75％(24/32),两者差异无统计学意义(x2=0.211,P ＞0.05).DTC肺外远处转移患者的疗效明显低于无肺外远处转移患者(x2 =3.868,P＜0.05),分别为3/10和70％(28/40).治疗后患者中位Tg水平由108.7 μg/L下降为78.3μg/L(Z=-0.698,P＞0.05).Tg升高患者17例,降低33例,按Tg判断治疗有效率66％(33/50).Tg＜ 100 μg/L组的疗效明显优于＞1000 μg/L组[80％ (20/25)与3/10,P=0.015],而100～1000 μg/L组与另外2组疗效间比较差异无统计学意义[67％(10/15),x2 =0.320,P＞0.05;P =0.111].综合131I显像及Tg结果判断,50例患者中6例临床治愈,25例好转,有效率62％ (31/50).结论 131I显像结合Tg是评价DTC肺转移131I治疗疗效的重要标准,Tg异常升高和肺外远处转移是DTC肺转移患者预后不良的因素.     

Technetium-99m-DTPA aerosol scintigraphy in amiodarone induced pulmonary toxicity in comparison with Ga-67 scintigraphy

Amiodarone hydrochloride, which is used in life-threatening cardiac tachyarrhythmia, has been known to cause amiodarone induced pulmonary toxicity (AIPT) as a complication. In this study we aimed to investigate the clinical value of technetium-99m diethylene triamine penta-acetic acid (DTPA) aerosol lung scintigraphy in patients with AIPT in comparison with gallium-67 (Ga-67) scan. The study group included 26 cases, 7 patients with diagnosis of AIPT (Group A), 8 patients receiving amiodarone therapy but without AIPT (Group B) and 11 healthy subjects as a control group (Group C). All patients underwent Ga-67 and Tc-99m-DTPA aerosol scintigraphy in addition to various laboratory tests, Ga-67 scintigraphy was positive in 4 of 7 AIPT patients but quite normal in Group B. A positive correlation was found (r = 0.52, p < 0.05) between kep values determined by Tc-99m-DTPA aerosol scintigraphy and the cumulative dose of amiodarone. The mean kep values were 2.04% +/- 0.85%/min, 1.30% +/- 0.42%/min and 0.86% +/- 0.19%/min for groups A, B and C, respectively. The mean clearance rate of group A was significantly faster than that of normals (p < 0.0005) and group B (p = 0.028). In addition, there was a significant difference between groups B and C (p = 0.015). In conclusion, Ga-67 lung scintigraphy is a useful method for the detection of AIPT but Tc-99m-DTPA aerosol scintigraphy offers better results than Ga-67 scintigraphy. Early changes in Tc-99m-DTPA clearance may be observed in patients receiving amiodarone. The kep value in patients with AIPT is noticeably increased with respect to the control group. With its favorable physical properties, low cost, lower radiation burden and its ability to be used as an objective measure for the pulmonary clearance rate, Tc-99m-DTPA aerosol scintigraphy appears to be promising in patients receiving amiodarone therapy.     

Differentiated thyroid cancer presenting with thyrotoxicosis due to functioning metastases

Thyrotoxicosis due to functioning metastases in differentiated thyroid cancer (DTC) is exceedingly rare. We report a case of follicular carcinoma in a 54-year-old manager, who presented with thyrotoxicosis, shortness of breath and lung metastases. Transbronchial biopsy of a pulmonary nodule demonstrated normal thyroid. This was interpreted as representing very well-differentiated thyroid cancer. CT, (131)I whole-body imaging and dosimetry is described following total thyroidectomy and repeated radioiodine administration (cumulative activity 34.6 GBq). The patient became asymptomatic with almost complete eradication of the pulmonary metastases. Potential complications of thyroid storm, bone marrow failure and pulmonary fibrosis following radioiodine are discussed, together with methods to minimise these risks.     

Investigation of pulmonary epithelial permeability in patients after hyperbaric oxygen therapy by 99mTc diethylenetriaminepentaacetic acid aerosol inhalation lung scintigraphy

The aim of this study was to evaluate the possibility of pulmonary epithelial permeability damage in patients after hyperbaric oxygen therapy (HBOT) by 99mTc diethylenetriaminepentaacetic acid (99mTc-DTPA) aerosol inhalation lung scintigraphy. Twenty-five controls and 21 patients with normal chest X-rays and no cigarette smoking for at least 1 year were recruited for the study. 99mTc-DTPA aerosol inhalation lung scans were performed after 20 HBOT sessions in 21 patients with refractory osteomyelitis or diabetic foot. The HBOT with 100% oxygen at 2.5 atm absolute for 100 min was performed five times a week. Clearance rates (%/min) of 99mTc-DTPA aerosol in each lung field were calculated from the dynamic images for 30 min. Clearance rates of 99mTc-DTPA aerosol were compared between patients and controls by the unpaired t test. Thirteen patients who had 99mTc-DTPA aerosol lung scans before and after HBOT therapy studies were tested for statistical significance by using the paired t test. There was no statistically significant difference (P>0.05, unpaired t test) between patients and controls in every lung field. For the 13 patients who had 99mTc-DTPA aerosol studies both before and after 20 HBOT sessions, the results also showed no statistically significant difference (P>0.05, paired t test). It is concluded that there was no demonstrable pulmonary epithelial permeability change under current clinical HBOT protocol.     

Impaired lung epithelial permeability in hepatitis C virus antibody positive patients detected by 99mTc-DTPA aerosol scintigraphy

Chronic hepatitis C virus (HCV) infection has been recently identified as an aetiological agent in idiopathic pulmonary fibrosis. The present study was designed to determine the pulmonary clearance rate of 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) in asymptomatic HCV antibody positive (HCV Ab+) patients and the role of 99mTc-DTPA aerosol scintigraphy in the early detection of lung involvement. Twenty-six non-smoker HCV Ab+ and HCV-RNA (+) patients (20 female, six male; aged 43+/-11 years), with no clinical pulmonary symptoms, and normal radiological findings, were studied. Thirty-one healthy non-smoker volunteers (24 female, seven male; aged 40+/-10 years) were taken as a control group. 99mTc-DTPA aerosol inhalation scintigraphy and pulmonary function tests were performed in all patients and in controls. On the basis of the scintigrams the percentage decline in activity per minute (Kep) was evaluated, which represented an accurate parameter of lung membrane permeability. The mean Kep values of healthy controls (0.78+/-0.13 for left lung, 0.79+/-0.14 for right lung) were significantly lower than HCV Ab+ patients (1.10+/-0.31 for left lung, 1.11+/-0.34 for right lung, P<0.001). But no significant change was observed in PFT (P>0.05). We conclude that subclinical alveolitis and/or interstitial lung disease may be present in patients with HCV Ab+, since it is known that an increase in the epithelial permeability of the lung is an early manifestation of interstitial disease.     

Alveolar epithelial permeability in patients with primary spontaneous pneumothorax as determined by Tc-99m DTPA aerosol scintigraphy

PURPOSE: Primary spontaneous pneumothorax (PSP) occurs subsequent to a disruption in the continuity of visceral pleura and escape of air into the pleural space. The cause of PSP is most often the rupture of subpleural blebs or bullae. It is usually difficult to detect evidence of pulmonary pathology. The purposes of the present study were (1) to investigate the changes of pulmonary alveolar epithelial permeability in patients with PSP as determined by Tc-99m DTPA aerosol lung scintigraphy, (2) to assess whether or not some differences exist between apical and basal parts of the lungs, and (3) to determine the relationship between the clearance rate of Tc-99m DTPA and the PFT results, the recurrence rate of PSP, and the percentage of pneumothorax in affected lung. MATERIAL AND METHODS: Thirteen PSP patients (two females, 11 males; mean age 32.5 +/- 11.8 years) with normal chest X-ray were studied. Thirteen healthy non-smoking volunteers (1 female, 12 males; mean age, 35.8 +/- 10 years) were selected as a control group. Tc-99m DTPA aerosol lung scintigraphy and PFT were performed in all patients and controls. Clearance rates (%/min) of Tc-99m DTPA aerosol in right and left lung field, and apical and basal parts of each lung were calculated from dynamic images for 15 min. RESULTS: There was no significant difference (p > 0.05) between patients and controls, or between apical and basal parts of each lung. No correlation was found between the clearance rate of Tc-99m DTPA and PFT results, the recurrence rate of PSP, or the percentage of pneumothorax. CONCLUSION: This study demonstrates that pulmonary epithelial permeability is not altered in PSP patients; the clearance rate of Tc-99m DTPA shows no difference between apical and basal parts of each lung.     

Tc-99m erythromycin lactobionate inhalation scintigraphy in parenchymal lung diseases

We have investigated Technetium 99m erythromycin lactobionate (Tc 99m EL) clearance from the lungs after inhalation, in the presence of an alveolitis. Eighteen patients (6 sarcoidosis, 7 idiopathic fibrosis, and 5 miliary tuberculosis) were imaged after the patients inhaled 1,110 MBq of Tc 99m EL. Clearance half time for the first 45 min, for 24 h, and retention at 24 h correlated with percentage of lymphocytes in bronchoalveolar lavage fluid (BAL) (r = .729, r = .883, and r = .826, respectively). There was a positive correlation between peripheral penetration (PP) and forced expiratory volume in 1 s (FEV1) (r = .806) and forced vital capacity (FVC) (r = .781). Retention was more marked in sarcoidosis compared with tuberculosis (0.025 < p < or = 0.05). Radioaerosol lung imaging may reflect the pulmonary function impairment in parenchymal lung diseases. Retention of Tc 99m EL may be related to number of BAL cells or presence of a lymphocytic alveolitis. Long residency time of Tc 99m EL in the lungs implies that erythromycin can also be administered by inhalation for therapeutic purposes.     

Relationship between cumulative radiation dose and salivary gland uptake associated with radioiodine therapy of thyroid cancer

AIM: To estimate the individual absorbed dose to the parotid and submandibular salivary glands in radioiodine therapy and its dependence from the previous cumulative therapy. METHODS: Fifty-five patients with differentiated thyroid carcinoma after thyroidectomy received 1-21 GBq (131)I using single activities of 1-6 GBq. The patients were stratified according to the cumulative activities into low-activity (1-2 GBq), middle-activity (3-7 GBq), and high-activity groups (9-21 GBq). The time-activity curves over the respective salivary glands were derived from multiple static calibrated images measured for each patient up to 48 h after ingestion of the radioiodine therapy capsule with a gamma camera. Manually drawn regions of interests were used to determine the background activities and the activities arising from the salivary glands. The gland volumes were determined by ultrasonography using appropriate volume models. RESULTS: The median absorbed dose per administered activity of each single parotid and submandibular gland was about 0.15 Gy.GBq (range, 0.1-0.3 Gy.GBq(-1)) and 0.48 Gy.GBq(-1) (range, 0.2-1.2 Gy.GBq(-1)), respectively. The maximum uptake of both gland types was significantly lower for the high-activity than for the low-activity groups and correlated with the mean cumulative administered activity of the activity groups. CONCLUSION: The iodine uptake of salivary glands is significantly reduced, whereas the absorbed dose per administered (131)I activity was not significantly decreased during the course of therapy. Comparing the well-known dose-effect relationships in external radiation therapy, the absorbed dose per administered (131)I activity is too low to induce comparable radiation damage, suggesting an inhomogeneous distribution of (131)I in human salivary glands.     

Outcome after radioiodine therapy in 107 patients with differentiated thyroid carcinoma and initial bone metastases: side-effects and influence of age

Initial bone metastases in patients with differentiated thyroid carcinoma are rare, especially in younger patients. Long duration of therapy and high activities of radioiodine are often necessary to induce remission of metastatic disease. The curative potential of radioiodine therapy, in particular in younger patients, has not yet been determined. In this retrospective study we evaluated the therapeutic outcome, total radioiodine activities and associated side-effects in 107 patients with initial bone metastases. Eight of the 107 patients were younger than 45 (37.5+/-7.3) years, and were classified as group 1 (stage II, "low risk", WHO classification). The remaining 99 patients were older than 45 (64.1+/-9.5) years, and formed group 2 (stage IV, "high risk", WHO classification). Total or partial remission was more frequently achieved in group 1 than in group 2 (62.5% vs 49.5%). Lower activities were needed in group 1 (18.89+/-15.08 GBq vs 41.97+/-31.25 GBq), and there were less marked alterations in the blood count in this group. In group 1, blood count alterations reached only grade I or II (WHO classification), whereas grade III and grade IV alterations as well as acute leukaemia were observed in group 2. In group 1, complete remission was achieved with radioiodine therapy (11.1 GBq) in three out of four patients with < or =3 bone metastases. Additional pulmonary metastases (present in 44 out of 107 patients) did not influence prognosis. We conclude that initial bone metastases in differentiated thyroid carcinoma can be treated with curative intent by means of radioiodine therapy, and that this approach has a particularly realistic chance of success in younger patients and those with a small number of metastases.     

Management of 131I therapy for thyroid cancer: cumulative dose from in-patients, discharge planning and personnel requirements

AIM: To provide a comprehensive overview with regard to the hospitalization/discharge planning and nursing staff requirements for the management of patients treated with radioiodine for differentiated thyroid carcinoma. METHODS: A statistical analysis of the fast clearance phase of 131I was performed in 265 hospitalized patients treated after total thyroidectomy with fixed doses ranging from 2590 to 9250 MBq. RESULTS: Two hundred and twenty-five cases were post-surgical ablation treatments and 40 cases were follow-up treatments. The 131I clearance was studied during hospitalization of 2-4 days. No clearance differences were found between the two groups. The median value of the biological half-time (T1/2bio) was 0.65 days, with a variability range of 0.30-2.03 days. A statistical model for the distribution of T(1/2bio) was reported. Some patients on maintenance haemodialysis were also studied, with T(1/2bio) values ranging from 1.6 to 2.6 days. The weekly cumulative dose to personnel from external exposure, corresponding to the 95th percentile, ranged from 0.1 mSv per GBq of administered activity (mSv x GBq(-1)) with a totally ambulant patient to 5.4 mSv . GBq with a totally helpless patient. With patients on maintenance haemodialysis, these values could increase from 1.2 to 1.7 times. The cumulative dose to close relatives was also estimated. The hospitalization times associated with 75% and 95% probabilities of patient discharge were calculated by varying the residual activity limit from 100 to 800 MBq. Finally, using the median T(1/2bio), personnel requirements were evaluated. With totally ambulant and semi-ambulant patients, about 0.5 and 1.0 personnel units per GBq of weekly administered activity were needed so as not to exceed an annual planning dose of 6 mSv per year. The treatment of patients with higher degrees of dependency was impractical. CONCLUSIONS: On the basis of statistical analysis, a better organization of in-patient treatment may be obtained, as well as more accurate preliminary evaluations of the cumulative doses to nursing staff and attending personnel, for the management of patients treated with radioiodine for differentiated thyroid carcinoma.     

Iodine-131 uptake in inflammatory lung disease: a potential pitfall in treatment of thyroid carcinoma

A mixed differentiated thyroid carcinoma was found in a small asymptomatic nodule in a 44-yr-old woman with recurrent chest infections and bronchiectasis. After total thyroidectomy and 162 mCi (6 GBq) radioiodine ablation there was uptake in the thyroid remnant and in both lungs, interpreted as lung metastases. In 2 years she received further three 162 mCi (6 GBq) doses of 131I, as scans showed very similar lung activity. Another scan, during thyroxin suppression, showed again activity in the lungs. A 47-yr-old male patient with similar respiratory disease and no history of thyroid disorder volunteered to undergo radioiodine scan while on triiodothyronine suppression. His scan, too, showed concentration in the lungs. The female patient died 7 years after the diagnosis of lung thyroid metastases was made. No metastasis was found at autopsy. Radioiodine lung uptake may occur in patients with chronic inflammatory lung disease, presenting a potential diagnostic pitfall in patients with differentiated thyroid carcinoma.