Radiation exposure to family members of patients with thyrotoxicosis treated with iodine-131

Purpose The purpose of this study was twofold: (1) to measure the radiation exposure to family members of out-patients with thyrotoxicosis treated with radioiodine, ¹³¹I, using the recommendations from the European Commission (EC) guidance and age-specific periods for behaviour restrictions; (2) to use the results to identify necessary restrictions to ensure recommended dose constraints.Methods The study population comprised 76 family members (46 adults and 30 children below the age of 18) of 42 patients. The patients were treated with an average activity of 417 MBq (range 260–600 MBq). They received oral and written EC recommendations about behaviour restrictions (translated into Norwegian). On the day of treatment we repeated the oral instructions to the patient and an adult family member. The time periods for restrictions were 14 days for children aged 0–10 years, 7 days for persons aged 11–59 years and 3 days for persons aged 60 years and older. Family members wore a thermoluminescent dosimeter (TLD) on each wrist day and night for 2 weeks. The doses received were adjusted to give an estimate of the expected values if the TLDs had been worn indefinitely.Results Radiation doses well below the recommended dose constraints were measured for all adult family members and children, except one 2-year-old child; in the latter case the mother probably did not comply with the instructions given.Conclusion The radiation dose to family members of thyrotoxic patients treated with up to 600 MBq of radioiodine is well below recommended dose constraints if EC instructions are given and compliance is adequate. The duration of restrictions for various age groups used in this study may be considered when establishing guidelines in Norway.     

Radiation exposure from gallium-67-citrate patients.

OBJECTIVE: Serial monitoring of patients was performed to determine the radiation exposure contributed by patients injected with 67Ga-citrate to their surroundings. Radiology and nursing staff distance exposure estimates were made for various patient care tasks and imaging tests. METHODS: Fifteen adult patients were surveyed early (mean 4.3 min) and 11 of the 15 were surveyed at 3 d (mean 68.8 h) postinjection. The standard adult lymphoma imaging activity of 333-407 MBq (9-11 mCi) resulted in a range of 3.7-8.1 MBq/kg (0.1-0.22 mCi/kg). Dose rate measurements were made in the anterior, posterior, and left and right lateral projections at the level of the umbilicus, at distances of patient's surface and at 30.5 cm and 100 cm with a calibrated ion chamber. Time of contact-routine task analyses also were obtained for nursing and radiology personnel. Using a radiation survey-derived biexponential pharmacokinetic relationship, radiation exposures were determined for hospital personnel and family members at various times after injection. RESULTS: Based on the study population survey results, the mean instantaneous exposures (microSv/h) for an administered activity of 370 MBq (10 mCi) 67Ga-citrate were determined. The task analyses revealed the maximum patient contact time for any procedure performed at a distance equal to, or less than, 30.5 cm was 30 min. CONCLUSION: The quantitation of radiation exposure scenarios from 67Ga-citrate patients has determined that no special precautions are necessary for medical personnel when performing routine tasks associated with these patients.     

Radiation exposure to sonographers from fluorine-18-FDG PET patients

OBJECTIVE: We estimated the amount of radiation exposure to sonographers from patients who were injected with 18F-fluorodeoxyglucose (FDG) at 2 and 3 h postinjection. METHODS: We studied 8 patients who were given between 380-420 MBq 18F-FDG. The patients were measured with a RADOS RDS-120 dosimeter between 2 and 3 h after FDG injection. The dosimetry measurement was taken at a distance of 0.5 m from the injected patient, a distance used by a sonographer to perform an abdominal ultrasound. Measurements were taken at the levels of the sonographer's shoulder, abdomen, and gonads. RESULTS: At the first measurement at 2 h, the mean exposures to the shoulder, abdomen, and gonads of the sonographer in pSv/h were 31.9+/-11.3, 37.1+/-9.5, and 32.8+/-11.8, respectively. At 3 h, the mean exposures to the shoulder, abdomen, and gonads were 21.5+/-4.2, 20.2+/-5.8, and 19.6+/-4.9, respectively. CONCLUSION: The amount of radiation exposure to a sonographer is minimal. Radiation exposure risks should be considered, however, if the sonographer comes into daily, repeated contact with patients who have been given 18F-FDG.     

恶性淋巴瘤病人CT和PET成像辐射暴露及死亡率风险

目的量化恶性淋巴瘤[霍奇金病(HD)或非霍奇金淋巴瘤(NHL)]病人CT和用18F-脱氧葡萄糖(18F-FDG)的正电子发射体层摄影(PET)的辐射暴露和死亡率风险。方法首先,用一个独特的诊断工作评估HD患儿和NHL成人的器官剂量。随后,编制寿命表评价辐射风险,还要考虑到疾病相关的死亡率。结果患HD的患儿进行医学成像累积的实际剂量为66mSv(新生儿)～113mSv(15岁儿童)。患NHL的成人进行医学成像累积的实际剂量为97mSv。辐射引起HD患儿中男孩的平均死亡率为0.4%[0.6%](方括号内的表示没有校正的与疾病相关的死亡率),女孩为0.7%[1.1%],在成人NHL中男性为0.07%[0.28%],女性为0.09%[0.37%]。结论考虑到与疾病相关的恶性淋巴瘤病人的预期寿命减少结果在于疾病本身较高的总死亡率,而辐射诱导的死亡发生率大幅度降低。来自CT和18F-FDGPET成像的适度辐射风险可以被认为是合理的,但成像过程应该注意,特别是对于儿童。     

Radiation exposure and mortality risk from CT and PET imaging of patients with malignant lymphoma

Objective

To quantify radiation exposure and mortality risk from computed tomography (CT) and positron emission tomography (PET) imaging with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) in patients with malignant lymphoma (Hodgkin’s disease [HD] or non-Hodgkin’s lymphoma [NHL]).

Methods

First, organ doses were assessed for a typical diagnostic work-up in children with HD and adults with NHL. Subsequently, life tables were constructed for assessment of radiation risks, also taking into account the disease-related mortality.

Results

In children with HD, cumulative effective dose from medical imaging ranged from 66?mSv (newborn) to 113?mSv (15 years old). In adults with NHL the cumulative effective dose from medical imaging was 97?mSv. Average fractions of radiation-induced deaths for children with HD [without correction for disease-related mortality in brackets] were 0.4% [0.6%] for boys and 0.7% [1.1%] for girls, and for adults with NHL 0.07% [0.28%] for men and 0.09% [0.37%] for women.

Conclusion

Taking into account the disease-related reduction in life expectancy of patients with malignant lymphoma results in a higher overall mortality but substantial lower incidence of radiation induced deaths. The modest radiation risk that results from imaging with CT and ¹⁸F-FDG PET can be considered as justified, but imaging should be performed with care, especially in children.

Key Points

• Survival of malignant lymphoma has improved dramatically over the past decades.
• PET and CT currently play important roles for malignant lymphoma patients.
• The potential hazard of ionising radiation has become an increasingly important issue.
• When assessing radiation risks, disease-related reduction in life expectancy should be considered.
• CT and ¹⁸ F-FDG PET create a modest radiation-induced mortality risk.

     

Dysprosium (165Dy) hydroxide macroaggregates for radiation synovectomy--animal studies

This paper reports the development of a new chemical formulation, Dy-HMA, to utilise the advantages of dysprosium 165 in radiation synovectomy of certain forms of arthritis. Dy-HMA is a sterile suspension of dysprosium hydroxide macroaggregates (approximately 6 mg Dy/ml) in saline with the majority of particles in the 3-5 microns range. The absence of ferric hydroxide and a higher concentration of dysprosium in the formulation offer advantages over dysprosium ferric hydroxide macroaggregates, Dy-165-FHMA. Biodistribution studies in rats and rabbits with Dy-HMA show less leakage than with Dy-FHMA and considerably less leakage than with yttrium silicate colloid. Rabbits treated with intra-articular injections of Dy-HMA equivalent to 10-30 times the typical clinical dose showed no signs of any toxic effects.     

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     

Radiation synovectomy using 165Dy ferric-hydroxide and oxidative DNA damage in patients with different types of arthritis.

Radiation synovectomy is an effective treatment for chronic synovitis refractory to pharmacological treatment in patients with rheumatoid or seronegative arthritis. Concerns persist about possible radiation-induced cytogenetic damage after radiation synovectomy leading to recommendations to use this technique only in the elderly. Micronucleus (MN) frequency in lymphocytes and urinary excretion of 8-hydroxy-2'-deoxyguanosine (8OHdG) as an indicator of cellular oxidative DNA base damage are biomarkers of radiation-induced cytogenetic damage. The course of both biomarkers was studied in patients with different types of chronic synovitis undergoing radiation synovectomy with very short-lived 165Dy-ferric-hydroxide (DFH). METHODS: Radiation synovectomy of the knee was performed in 13 men and 12 women (mean age, 44+/-15 y) using a mean activity of 9.48+/-1.65 GBq 165Dy-DFH in 27 consecutive treatments. MN frequency in lymphocytes and urinary excretion of 8OHdG, measured by high-performance liquid chromatography, were assessed before and 4 (MN only) and 20 h after radiation synovectomy. RESULTS: Urinary excretion of 8OHdG in patients (in micromol/mol creatinine; pretreatment mean, 3.1+/-3.4; median, 2.27) was not significantly different from that in healthy volunteers (mean, 2.0+/-1.2; median, 1.87) and not altered by radiation synovectomy (post-treatment mean, 2.5+/-1.5; median, 2.04, NS). An increase in 8OHdG levels after radiation synovectomy of more than 1 SD was found in only 1 patient, who experienced leakage to the lymph nodes but who already had elevated urinary 8OHdG levels before treatment. The frequency of MN/500 binucleated cells (BNCs) was slightly lower in patients (pretreatment mean, 4.3+/-2.6; median, 4.25) than in healthy volunteers (mean, 5.4+/-2.3; median, 5.3) and did not significantly change after therapy, either (4-h post-treatment mean, 3.9+/-2.1, median, 3.8; 20-h post-treatment mean, 4.1+/-2, median 3.8 MN/500 BNC). In 22 of 27 treatments, no leakage to nontarget organs could be monitored, whereas leakage to the local lymph nodes and the liver was detected after 5 treatments. CONCLUSION: Radiation synovectomy using 165Dy-DFH causes no significant radiation burden to most patients as indicated by the absence of adverse changes in levels of biomarkers of cytogenetic damage and a low incidence of leakage. These data suggest that the risk of malignancy may not be elevated.     

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.     

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.     

Monitoring of the biodistribution and biokinetics of dysprosium-165 ferric hydroxide with a shadow-shield whole-body counter

Radiation synovectomy is indicated when conventional pharmacological treatment of chronic synovitis has proved insufficient. In these cases dysprosium-165 ferric hydroxide (DFH) has been demonstrated to be clinically effective. After application of the agent, blood activity measurements and monitoring of activity distribution by gamma camera imaging over the local lymph nodes and the liver are commonly performed for control of possible leakage. In addition, we have used a shadow-shield whole-body counter with a profile facility to evaluate the biokinetics and biodistribution of¹⁶⁵Dy-DFH. Fifteen intra-articular injections were performed in 13 patients who received a median activity of 6.8 GBq (range 0.5-9.9 GBq)¹⁶⁵Dy-DFH. Activity profiles were obtained with the whole-body counter 2, 4 and 6 h after injection of¹⁶⁵Dy-DFH. The doses to non-target organs were calculated using the software MIRDOSE 3. In 10 of 15 treatments, absence of any leakage could be demonstrated. The effect of scattered rays could be observed in 14 measurements. In three patients small amounts of activity could be detected in the urinary bladder and in three patients activity was detected in the local inguinal lymph nodes, while no leakage could be detected by camera imaging. In these cases the individual doses to the bladder were 15 Gy, 65 mGy and 50 mGy, and those to the lymph nodes, 0.54 Gy, 0.89 Gy and 2.41 Gy. The whole-body counter also enabled the monitoring of activity profiles related to more complex pathological structures. In conclusion, using a whole-body counter activity leakage could be detected with much higher sensitivity than by using a gamma camera. The biodistribution of¹⁶⁵Dy-DFH could be determined, and leakage could be localised and related to organs. These results encourage the use of a whole-body counter to identify, the site and extent of activity leakage.     

Radiation synovectomy with 165Dy-FHMA: lymph node uptake and radiation dosimetry calculations

The lymph node uptake of 165Dy was measured in 25 patients treated by radiation synovectomy via intra-articular injection of 165Dy-ferric hydroxide macroaggregates (FHMA). An average of 0.12% of the injected dose was found in the inguinal lymph nodes 19h post injection. This results in a lymph node of 16.6 rad (166 mGy), a dose significantly less than that reported following radiation synovectomy with other radiocolloids. Dosimetry calculations for the intra-articular injection of 165Dy-FHMA are provided in the appendix.     

直接摄影检查患者的照射剂量分析

目的 通过对不同部位直接摄影(DR)检查的医学数字成像和传输(DICOM)文件信息中的患者剂量信息的统计,调查不同投照部位DR摄片的照射剂量分布范围,分析影响DR检查照射剂量的因素。方法 随机选取浙江省某三甲医院2009年1月至4月5160次DR摄片,包括胸部、胸椎及腰椎正、侧位、腹部前后位及骨盆正位。应用软件自动提取每例患者检查中DICOM信息文件中的剂量面积乘积(DAP),并结合照射野的范围,计算各部位DR检查的入射表面剂量(ESD)。结果 腹部前后位、腰椎侧位、胸椎正侧位的变异系数在60%以下;胸部正侧位、腰椎正位、骨盆正位的变异系数为60%~80%。各个部位的DAP最大值与最小值比值,除腹部前后位较小为3倍,其余部位差异较大。其中,腰椎正位最大差别为46倍、腰椎侧位30倍,胸椎侧位、胸部正位、侧位、骨盆正位、胸椎正位分别为23、23、18、16、11倍。通过计算得到ESD值选择75%分位点与现行普通摄片诊断参考水平(DRL)比较后发现,胸部正、侧位分别下降75%和73%;腰椎正侧位下降66%和77%;胸椎正侧位下降85%和84%;骨盆正位下降88%;腹部前后位下降88%。结论 DR检查中各个部位的DAP与ESD值存在较大变动,ESD值与现行的常规摄片的DRL相比有较大下降;有必要回顾分析DR摄片的患者照射剂量,对患者照射剂量与图像质量进行质量管理。