Real-life radiation burden to relatives of patients treated with iodine-131: a study in eight centres in Flanders (Belgium)

In view of the EURATOM 96/29 [1] regulations, a prospective multicentre study was performed to evaluate the present guidelines given to relatives of patients treated with iodine-131 for both thyroid carcinoma and thyrotoxicosis, based on the real-life radiation burden. This study comprised 166 measurements carried out on a group of 94 relatives of 65 patients. All relatives wore a thermoluminescent dosemeter (TLD) on the wrist for 7 days. Sixty-one relatives agreed to wear another TLD for an additional 7 days. TLD were placed on nine patients’ bedside tables. The eight participating centres were arbitrarily divided into three groups according to the period of time they advised their patients to sleep separately. Groups I, II and III respectively advised their patients to sleep separately for 0, 7–10 and 14–21 days. The median dose received by in-living relatives of thyroid carcinoma patients during the 14 days following hospital discharge was 281 μSv (doses to infinity not calculated); the median dose to infinity received by in-living relatives of ambulatory treated thyrotoxicosis patients was 596 μSv, as compared with 802 μSv for in-living relatives of hospitalised thyrotoxicosis patients. In general the children of patients received a significantly (P<0.1) lower mean dose than their partners. For thyroid carcinoma patients, only two relatives out of 19 (10%) exceeded the EURATOM 96/29 limit of 1 mSv/year. For thyrotoxic patients, 28% of relatives exceeded the EURATOM 96/29 limit, but none of them were relatives of patients who followed guidelines for 21 days. The results of this study indicate that sleeping separately for 7 days, after a period of hospitalisation of 2–3 days, will usually be sufficient for thyroid carcinoma patients. For thyrotoxicosis patients, up to 21 days of sleeping separately could be necessary in order to strictly abide by EURATOM 96/29. Therefore, the authors propose the implementation of a non-rigid dose constraint for people who ”knowingly and willingly” help patients treated with ¹³¹I, while still following the ALARA principle. Received 16 January and in revised form 21 May 1998     

Radiation exposure of the families of outpatients treated with radioiodine (iodine-131) for hyperthyroidism

Patients who receive radioiodine (iodine-131) treatment for hyperthyroidism (195–800 MBq) emit radiation and represent a potential hazard to other individuals. Critical groups amongst the public are fellow travellers on the patient’s journey home from hospital and members of the patient’s family, particularly young children. The dose which members of the public are allowed to receive as a result of a patient’s treatment has been reduced in Europe following recently revised recommendations from ICRP. The annual public dose limit is 1 mSv, though adult members of the patient’s family are allowed to receive higher doses, with the proviso that a limit of 5 mSv should not be exceeded over 5 years. Unless the doses received during out-patient administration of radioiodine can be demonstrated to comply with these new limits, hospitalisation of patients will be necessary. The radiation doses received by family members (35 adults and 87 children) of patients treated with radioiodine at five UK hospitals were measured using thermoluminescent dosimeters mounted in wrist bands. Families were given advice (according to current practice) from their treatment centre about limiting close contact with the patient for a period of time after treatment. Doses measured over 3–6 weeks were adjusted to give an estimate of values which might have been expected if the dosimeters had been worn indefinitely. Thirty-five passengers accompanying patients home after treatment also recorded the dose received during the journey using electronic (digital) personal dosimeters. For the ”adjusted” doses to infinity, 97% of adults complied with a 5-mSv dose limit (range:0.2–5.8 mSv) and 89% of children with a 1-mSv limit (range: 0.2–7.2 mSv). However 6 of 17 children aged 3 years or less had an adjusted dose which exceeded this 1 mSv limit. The dose received by adults during travel was small in comparison with the total dose received. The median travel dose was 0.03 mSv for 1 h travel (range: 2 μSv-0.52 mSv for 1 h of travel time). These data suggest that hyperthyroid patients can continue to be treated with radioiodine on an out-patient basis, if given appropriate radiation protection advice. However, particular consideration needs to be given to children aged 3 years or younger. Admission to hospital is not warranted on radiation protection grounds. Received 31 December 1998 and in revised form 20 March 1999     

Prostaglandins as biochemical markers of radiation injury to the salivary glands after iodine-131 therapy?

Because salivary glands, as well as thyroid tissue, are able to concentrate radioiodine, the treatment of thyroid diseases with iodine-131 may have secondary effects on salivary gland function which seriously impair the quality of life. Such effects include sialoadenitis and xerostomia. Salivary secretion is stimulated by prosta- glandins (PGs). In this study we evaluate whether ¹³¹I therapy influences the levels of PGs in saliva. Patients who had previously received ¹³¹I for treatment of hyperthyroidism or differentiated thyroid cancer and healthy volunteers were studied. Levels of PGs [6-oxo-PGF_1α, bicyclo-PGEm, thromboxane B₂ (TXB₂), PGF_2α] in unstimulated saliva were measured using enzyme immunoassay. Significantly lower levels of 6-oxo-PGF_1α, bicyclo-PGEm and PGF_2α and higher levels of TXB₂ were found in the group of patients in comparison with the controls. Differences between patients and controls were more pronounced in smokers. This study demonstrates that salivary gland uptake of ¹³¹I significantly affects PG levels in saliva. Received 25 September and in revised form 24 November 1997     

Metastatic phaeochromocytoma with a long-term response after iodine-131 metaiodobenzylguanidine therapy

Iodine-131 metaiodobenzylguanidine ([¹³¹I] MIBG), a radiopharmaceutical agent, is used for treating malignant phaeochromocytoma. [1311]MIBG therapy results in a hormone response rate of approximately 50%, but generally it yields only a partial or no tumour response. We present a case of a 46-year-old woman with a familial history of von Hippel-Lindau disease, who was treated with [1311]MIBG for a metastatic phaeochromocytoma involving the lungs, liver and bones. The patient received a cumulative dose of 33.3 GBq (900 mCi) and a complete hormone response was observed, as evaluated on the basis of catecholamine and metanephrine levels. Conventional radiography, computerized tomography and [1311]MIBG scintigraphy indicated that a near-complete tumour regression was achieved, with no evidence of relapse during a 4-year follow-up period. This case thus demonstrates that treatment with [¹³¹I]MIBG may lead to a dramatic tumour response in malignant phaeochromocytoma presenting both soft tissue and bone metastases.     

Fetal dose estimates and the ICRP abdominal dose limit for occupational exposure of pregnant staff to technetium-99m and iodine-131 patients

The International Commission on Radiological Protection has recently recommended a supplementary dose limit of 2 mSv to the abdominal surface of a pregnant member of staff in order to provide protection to her fetus comparable to that in members of the public, whose annual limit is recommended to be 1 mSv. In order to determine whether this apparent attenuation factor of 50% is appropriate for nursing and imaging staff exposed to nuclear medicine patients, estimates were made of the ratios of the maternal abdominal surface to fetal dose appropriately weighted for time, distance and dose rate. Thermoluminescent dosimeter (TLD) measurements were made at various depths in an anthropomorphic phantom irradiated at different distances by a distributed source of either technetium-99m or iodine-131 in order to determine the corresponding attenuation factors at the average fetal midline depth. Dose estimates were based on these factors and on published values of dose rate and exposure times for nursing and imaging staff at these distances from the patient. Fetal doses to nursing staff caring for an adult^99mTc patient were estimated to vary from 86 Sv to 1.6 Sv, with the corresponding ratio of the abdominal surface to fetal dose varying from about 1.8:1 to 1.5:1 as the patient became less dependent on nursing care and the mean distance from the patient increased. Fetal doses to imaging staff varied from 1.12 Sv to 0.17 Sv for three types of^99mTc scan, but the ratio only varied from 1.4:1 to 1.3:1. Fetal doses to imaging staff were estimated to be 6.7 Sv and 9.0 Sv for a whole-body scan of a thyroid cancer patient after 1311 ablation and therapy respectively, and the ratio was 1.3:1 for both types of scan. It was concluded that for a pregnant ward nurse or imaging technologist exposed to an adult or paediatric patient administered^99mTc or¹³¹I, a dose limit of 1.3 mSv to the maternal abdominal surface will restrict their fetal dose to 1 mSv. A pregnant imaging technologist should perform no more than six adult^99mTc studies or one¹³¹I whole-body scan per day, and may have to wear a more sensitive personal dosimeter than a film badge.     

Aspects of fetal thyroid dose following iodine-131 administration during early stages of pregnancy in patients suffering from benign thyroid disorders

Detrimental effects on the thyroid of the developing fetus as a result of iodine-131 treatment for thyrotoxicosis of the mother in the first trimester of pregnancy are discussed. Dose estimations under typical clinical circumstances yield a fetal thyroid dose of 100– 450 Sv. This dose may increase considerably if the blood concentration of ¹³¹I in the mother remains high. Under such circumstances there may be fetal thyroid dysfunction, which can lead to severe abnormalities. Received 22 February and in revised form 16 June 1999     

Pregnancy after high therapeutic doses of iodine-131 in differentiated thyroid cancer: potential risks and recommendations

Seventy female patients who had been treated with high doses of iodine-131 for differentiated thyroid cancer (DTC) and who had a subsequent pregnancy were evaluated. The total ¹³¹I dose ranged from 1.85 to 16.55 GBq (mean±SD=4.39±25.20 GBq). Age at first therapy ranged from 15 to 36 years (mean±SD = 24.3±5.0 years) and the interval from ¹³¹I therapy topregnancy varied from 2to 10 years (mean±SD = 5.3±2.8 years). The estimated radiation doseto the gonads ranged from 10 to 63 cGy (mean±SD = 24.0±13.5 eGy). All patients were treated with l-thyroxine at doses capable of suppressing thyroid-stimulating hormone. Seventy-three children were followed-up and seven pregnancies are still in progress. One child was affected by Fallot's trilogy and three had a low birth weight though with subsequent normal growth; the others were healthy with subsequent normal growth. No newborn with clinical or biochemical thyroid dysfunctions was found. Two spontaneous abortions during the second month of pregnancy were recorded. One of two patients in question subsequently had two healthy children. On the basis of these data, previous administration of high ¹³¹I doses does not appear to be a valid reason for dissuading young female DTC patients from considering pregnancy. However, patients should be advised to avoid pregnancy after ¹³¹I administration for a period sufficient to ensure complete elimination of the radionuclide and to permit confirmation of complete disease remission, i.e. at least 1 year in our opinion.     

Radiochemical purity of iodine-131 labelled metaiodobenzylguanidine infusion fluids: a report from clinical practice

Iodine-131 labelled metaiodobenzylguanidine ([¹³¹I]MIBG) has a diagnostic and therapeutic role in the management of neural crest tumours, particularly neuroblastoma, malignant phaeochromocytoma and paraganglioma. With therapeutic amounts of [¹³¹I]MIBG it is essential that the amount of free [¹³¹I]iodide, the most important impurity, is known. In clinical practice the percentage of free [¹³¹I]iodide seen in a [1311]MIBG infusion concentrate increased from 2.2%±0.67% to 3.6%±0.39% (mean ± SD; n=23) 1 day after production. At the time of use the percentage of free [¹³¹I]iodide was always below our upper limit of acceptance of 5%. Since 5% of free [¹³¹I]iodide is within practical reach in our environment, a higher percentage at the time of pre-administration quality control is not accepted in the Netherlands Cancer Institute. Correspondence to: A.R. Wafelman     

甲亢手术与丙基硫氧嘧啶对131I疗效的影响

目的 探讨甲亢术后复发和丙基硫氧嘧啶（PTU）治疗后对^131I疗效的影响。方法 2003年1月至2004年12月在我院核医学科治疗的甲亢术后复发病人，未经过抗甲状腺药物治疗41例为术后复发组；按同时期^131I治疗次序编号，从未经过手术及抗甲状腺药物治疗的病例中随机抽取41例为对照组（未治疗组）；从只经PTU治疗的病例中随机抽取41例为PTU组，采用标准剂量法给予^131I治疗，分析治疗后3与6个月随访资料。结果 未治疗组^131I治疗后3和6个月甲亢治愈率分别为90．24％（37141）和92．68％（38/41），无效率分别为9．76％（4／41）和7．32％（3／41）；PTU治疗组^131I治疗后3和6个月甲亢治愈率分别为43．90％（18／41）和53．66％（22／41），无效率分别为56．10％（23／41）和46．34％（19／41），与未治疗组比较均为P〈0．01；术后复发组^131I治疗后3和6个月甲亢治愈率分别为68．29％（28／41）和70．73％（29／41），无效率分别为31．71％（13／41）和29．27％（12／41），与未治疗组比较均为P〈0．05。结论 甲亢在^131I治疗前经外科手术或PTU治疗，将影响^131I治疗效果，降低甲亢^131I的治愈率。     

Scintigraphic imaging and turnover studies with iodine-131 labelled serum amyloid P component in systemic amyloidosis

Radiolabelled serum amyloid P component (SAP) is a specific tracer for amyloid. Iodine-123 has ideal physical characteristics for scintigraphy but is expensive and not widely available. Here we report serial imaging and turnover studies in which we labelled SAP with iodine-131, a cheap alternative isotope which would be expected to yield poorer images but permit more prolonged turnover measurements. Imaging and plasma clearance and whole body retention (WBR) of tracer were studied for up to 7 days in ten patients with proven systemic AL amyloidosis and two patients in whom the diagnosis was suspected, after i.v. administration of about 37 MBq of ¹³¹I-SAP. Normal blood pool images were obtained in the latter two subjects and amyloidosis was subsequently refuted histologically. WBR at 48 h was <60% and 6-h plasma activity was >65% of the injected dose (i.d.). Among the other ten patients, amyloid deposits were identified in the spleen in eight cases, liver in five and kidneys in four; other sites that gave positive results included bone, joints and soft tissues, and the myocardium in one case. Up to 95% of the tracer localised into amyloid within 6-h, and the values for WBR became progressively more discriminating during the study period, exceeding the normal reference value (<25%) in all cases by day 7. The optimal imaging time was found to be between 24 and 48 h. The duration of the study enabled us to measure the tracer elimination half-life which was increased in all cases by up to tenfold. Follow-up studies performed after 2–24 months in four patients who were treated with iododoxorubicin showed regression of amyloid in one patient and a small increase in one case; in the other two patients the imaging and turnover studies were identical to baseline. Despite its unfavourable imaging characteristics, ¹³¹I-SAP produced diagnostic scans in every patient in this series and, coupled with the detailed turnover information, is adequate for monitoring disease progress. Received 30 December 1997 and in revised form 16 April 1998     

10种介入诊疗程序中患者的辐射剂量调查

目的 调查研究介入诊疗程序中患者的受照剂量,评估其放射诊疗风险.方法 利用配置有符合IEC 60601-2标准的穿透型电离室的飞利浦Allura Xper FD20 DSA系统,收集记录10种介入诊疗程序共198例患者的剂量参数,估算出可供评估皮肤损伤的最高皮肤剂量及有效剂量.结果 累计透视时间范围为2.1～80.9 min,摄影帧数范围为15～678帧,剂量面积乘积范围为11～825 Gy·cm2,累计剂量范围为24～3374 mGy.有16例患者最高皮肤剂量超过1 Gy,79例患者有效剂量大于20 mSv.结论 有部分病例的最高皮肤剂量超过了皮肤损伤阈值,所以对患者的放射防护应给予足够的重枧.

Abstract：

Objective To investigate radiation dose to the patients undergoing interventional radiology and make radiation risk assessment.Methods Data was collected on 198 instances of 10 interventional radiology procedures by using Philips Allura Xper FD20 DSA, which was equipped with the transparent ionization chamber system in compliance with IEC 60601-2.Patient peak skin dose and effective dose were estimated.Results Cumulative fluoroscopy time was 2.1 - 80.9 min, and number of images monitored for PSD were above 1 Gy and 79 cases monitored for E were above 20 mSv.Conclusions Substantial number of cases exceeded the dose threshold for erythema.Due attention should be paid to radiation protection of patients.     

Estimation of the Release Time from Isolation for Patients with Differentiated Thyroid Cancer Treated with High-dose I-131

Purpose

Patients receiving high-dose I-131 to treat differentiated thyroid cancer are isolated from visitors to limit radiation exposure to reasonable levels. The appropriate isolation time is unclear and has not been reported in Korea. The purpose of this study was to estimate the isolation time and investigate the possibility of earlier release from isolation.

Methods

This study was a retrospective analysis of data from 71 patients (10 men and 61 women; mean age, 49 ± 11.1 y) who received 3.7 GBq (47 patients), 5.55 GBq (23 patients), or 7.4 GBq (1 patient) of I-131 between January 2008 and December 2008. The radiation dose was measured with a fixed probe placed inside the isolation room. The total estimated dose equivalent (TEDE) to family members, the time required for the external dose rate to become <0.07 mSv/h, and the time required for whole-body retention to become <1.2 GBq were calculated.

Results

By the TEDE criterion (<5 mSv), 70 of 71 patients (98.6%) could have been released without isolation. By the external dose rate criterion, 10 of 71 (14.1%) and 60 of 71 patients (84.5%) could have been released without isolation and within 24 h, respectively. With whole-body retention criterion, 19 of 71 (26.8%) and 48 of 71 patients (67.6%) could have been released within 24 h and within 48 h, respectively.

Conclusions

Appropriate release times were estimated and compared using different criteria. Most patients could have been released without isolation or within 24 h of radiation treatment.     

Evaluation of cardiac adrenergic neuronal damage in rats with doxorubicin-induced cardiomyopathy using iodine-131 MIBG autoradiography and PGP 9.5 immunohistochemistry

Doxorubicin is one of the most useful anticancer agents, but its repeated administration can induce irreversible cardiomyopathy as a major complication. The purpose of this study was to investigate doxorubicin toxicity on cardiac sympathetic neurons using iodine-131-metaiodobenzylguanidine (MIBG) and protein gene product (PGP) 9.5 immunohistochemistry, which is a marker of cardiac innervation. Wistar rats were treated with doxorubicin (2 mg/kg, i.v.) once a week for 4 (n=5), 6 (n=6) or 8 (n=7) weeks consecutively. Left ventricular ejection fraction (LVEF), calculated by M-mode echocardiography, was used as an indicator of cardiac function. Plasma noradrenaline (NA) concentration was measured by high-performance liquid chromatography (HPLC). ¹³¹I-MIBG uptake of the left ventricular wall (24 ROIs) was measured by autoradiography. ¹³¹I-MIBG uptake pattern was compared with histopathological results, the neuronal population on PGP 9.5 immunohistochemistry and the degree of myocyte damage assessed using a visual scoring system on haematoxylin and eosin and Masson’s trichrome staining. LVEF was significantly decreased in the 8-week group (P<0.05). The serum NA level also showed no statistical difference until 4 weeks and was significantly increased in the 8-week group (P<0.05). MIBG uptake was decreased in the 6- and 8-week groups (P<0.05), and was closely correlated with the reduction in the number of nerve fibres on PGP 9.5 stain. Myocyte damage was seen only in the 8-week group. Neuronal population and the ¹³¹I-MIBG uptake ratio of subepicardium to subendocardium were significantly increased (P<0.05) in the 8-week group as compared with the control group. It may be concluded that radioiodinated MIBG is a reliable marker for the detection of cardiac adrenergic neuronal damage in doxorubicin-induced cardiomyopathy; it detects such damage earlier than do other clinical parameters and in this study showed a good correlation with the reduction in the neuronal population on PGP 9.5 stain. The subendocardial layer appeared to be more vulnerable to doxorubicin than the subepicardium. Received 14 December 1999 and in revised form 2 February 2000     

Radiation protection and dosimetry issues for patients with prostate cancer after I-125 low-dose-rate brachytherapy permanent implant

PurposeThe aim of this work was to analyze the exposure rates measured in the proximity of patients who underwent prostate low-dose-rate brachytherapy with I-125 implant. Effective doses to relatives and to population were computed to estimate the time to reach radioprotection dose constraints.Methods and MaterialsMeasurements were obtained from 180 patients, whereas the body mass index was calculated and reported for 77 patients. The day after the implant, $\dot{K}$ measurements were conducted at various skin distances and positions and converted to effective doses. A theoretical model was developed to estimate effective doses from total implanted activity. The latter was approximated with a 10-mL vial inside the patient.ResultsThe $\dot{K}$ measurements showed a low correlation with the total implanted activity, albeit an increasing trend of $\dot{K}$ was observed on increasing the activity. A stronger correlation was found between body mass index and $\dot{K}$ measurements.The effective dose to population is in general lower than dose constraints as well as the effective doses to relatives, with the exception of children and pregnant women, who command special precautions. We report differences between the experimental model– and theoretical model–based dose evaluation together with their comparison with previous studies found in literature.ConclusionsBased on the $\dot{K}$ measurements and the results of the present analysis, it is possible to provide the patient with radiation safety instructions specifically tailored to his relatives’ habits and working environment.     

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患者体内残留辐射剂量及病房辐射剂量的监测分析

目的 评估住院131I治疗分化型甲状腺癌（DTC）患者体内残留辐射剂量达到出院要求的时间,以及患者所住病房和用具的辐射情况。 方法 选取2015年1月至2017年3月在中山大学附属第三医院核医学科接受术后131I住院治疗的DTC患者143例,其中男性46例、女性97例,年龄（37.6±12.4）岁。按给药剂量分为3.70、5.55和7.40 GBq 3组,每组患者分别为51、51、41例。患者在服用131I后0.5、2、4、8、12、24、36、48、72、80 h,在距离患者1 m外使用实时辐射监测仪测定辐射剂量率,估算患者体内放射性活度的变化情况。在患者出院后当天应用表面辐射污染监测仪对病房环境及患者使用过的床被进行表面污染辐射剂量的监测。对3组辐射剂量率数据进行单因素方差分析。 结果 服131I治疗 0.5 h后3组DTC患者1 m外的辐射剂量率[（597.5±196.3）、（794.5±254.2）、（1114.1±258.5） μSv/h]的差异有统计学意义（F=62.757,P<0.01）,但随着时间的延长,辐射剂量水平按类似指数曲线的变化规律迅速下降,且3组间差距逐渐缩小,在服131I 治疗72 h后3组患者1 m外的辐射剂量率[（13.3±10.7）、（16.1±9.7）、（21.9±14.5） μSv/h]的差异无统计学意义（F=2.313,P>0.05）。服131I治疗后80 h 95.8%（137/143）DTC患者1 m外辐射剂量率低于23.3 μSv/h。出院后患者使用过的床单、病服、病房地面及洗手间门口地面的表面剂量率分别为（3.9±1.2）、（4.1±1.9）、（3.8±1.6）、（6.2±2.6） μSv/h,均低于相应规定的辐射剂量限制水平。 结论 使用不超过7.40 GBq 131I治疗的DTC患者在服用131I治疗80 h后,绝大多数患者体内残留131I剂量低于国家规定的辐射限制水平。出院后患者所处病房环境及使用过的床单、病服的辐射污染均低于限制水平,无需特殊处理。     

Radiation exposure of the families of outpatients treated with radioiodine (iodine-131) for hyperthyroidism.

Patients who receive radioiodine (iodine-131) treatment for hyperthyroidism (195-800 MBq) emit radiation and represent a potential hazard to other individuals. Critical groups amongst the public are fellow travellers on the patient's journey home from hospital and members of the patient's family, particularly young children. The dose which members of the public are allowed to receive as a result of a patient's treatment has been reduced in Europe following recently revised recommendations from ICRP. The annual public dose limit is 1 mSv, though adult members of the patient's family are allowed to receive higher doses, with the proviso that a limit of 5 mSv should not be exceeded over 5 years. Unless the doses received during out-patient administration of radioiodine can be demonstrated to comply with these new limits, hospitalisation of patients will be necessary. The radiation doses received by family members (35 adults and 87 children) of patients treated with radioiodine at five UK hospitals were measured using thermoluminescent dosimeters mounted in wrist bands. Families were given advice (according to current practice) from their treatment centre about limiting close contact with the patient for a period of time after treatment. Doses measured over 3-6 weeks were adjusted to give an estimate of values which might have been expected if the dosimeters had been worn indefinitely. Thirty-five passengers accompanying patients home after treatment also recorded the dose received during the journey using electronic (digital) personal dosimeters. For the "adjusted" doses to infinity, 97% of adults complied with a 5-mSv dose limit (range:0.2-5.8 mSv) and 89% of children with a 1-mSv limit (range: 0.2-7.2 mSv). However 6 of 17 children aged 3 years or less had an adjusted dose which exceeded this 1 mSv limit. The dose received by adults during travel was small in comparison with the total dose received. The median travel dose was 0.03 mSv for 1 h travel (range: 2 microSv-0.52 mSv for 1 h of travel time). These data suggest that hyperthyroid patients can continue to be treated with radioiodine on an out-patient basis, if given appropriate radiation protection advice. However, particular consideration needs to be given to children aged 3 years or younger. Admission to hospital is not warranted on radiation protection grounds.     

Measurement of the internal dose to families of outpatients treated with <Superscript>131</Superscript>I for hyperthyroidism

Objective  The aim of this study was to measure the internal dose received by family members from ingestion of radioactive contamination after outpatient therapy. Materials and methods  Advice was given to minimise transfer of radioiodine. Home visits were made approximately 2, 7 and 21 days after treatment to measure radioactivity in the thyroids of family members. A decay correction was applied to radioactivity detected assuming ingestion had occurred at the earlier contact time, either the day of treatment or the previous home visit. An effective half-life of 6 or 7 days was used depending on age. Thyroid activity was summed if activity was found at more than one visit in excess of the amount attributable to radioactive decay. Effective dose (ED) was calculated using ICRP72. Results and discussion  Fifty-three adults and 92 children, median age 12 (range 4–17) years participated. Median administered activity was 576 (range 329–690) MBq ¹³¹I. Thyroid activity ranged from 0 to 5.4 kBq in the adults with activity detected in 17. Maximum adult ED was 0.4 mSv. Thyroid activity ranged from 0 to 11.8 kBq in the children with activity detected in 26. The two highest values of 5.0 and 11.8 kBq occurred in children aged 5 and 14 years from different families. Eighty-five children had no activity or <1 kBq detected. ED was <0.2 mSv in 86 out of 92 children (93%). Previous published data showed 93% of children received an ED ≤0.8 mSv from external irradiation. Conclusion  With advice, families of outpatients receiving radioiodine should be able to comply with statutory dose limits and constraints.     

介入栓塞与^131I治疗Graves病近期疗效的对比分析

目的对比分析甲状腺动脉介入栓塞和131I治疗Graves病近期疗效的差异。方法对接受131I和甲状腺动脉栓塞治疗的各42例Graves病患者,行造影、SPECT/CT显像检查治疗前后甲状腺形态、大小,放射免疫法检测治疗前后3、6和12个月血清中FT3、FT4、TSH浓度及促甲状腺受体抗体(TRAb)活度和治疗后并发症出现的关系,并对以上数据进行统计学分析。结果两种治疗方法近期疗效无显著差异,介入治疗组治疗后早期严重并发症的发生率明显高于131I治疗组,而131I治疗组有更高的甲状腺功能减退(甲减)发生率。结论甲状腺动脉介入栓塞和131I治疗Graves病患者疗效肯定,131I可用于初诊及其他方法疗效不佳的患者,介入栓塞治疗可用于抗甲状腺药物疗效不佳、无法手术及甲状腺摄131I率低不能行131I治疗者,特别对一些难治性、顽固性甲状腺功能亢进有效。介入疗法可作为Graves病可选择的手段。     

Clinical implication of F-18 FDG PET/CT for differentiated thyroid cancer in patients with negative diagnostic iodine-123 scan and elevated thyroglobulin

This study aims to investigate the usefulness of F-18 FDG PET/CT in differentiated thyroid cancer (DTC) with elevated serum thyroglobulin (Tg) but negative iodine-123 (I-123) scan.