Análisis de las fortalezas,oportunidades, debilidades y amenazas de la tomografía computarizada de doble energía en el diagnóstico por la imagen de la cabeza y el cuello

Technological development of dual-energy computed tomography (DECT) can play an important role in head and neck area. Multiple innovative applications have evolved, optimizing images, achieving metallic artifact reduction, differentiating materials with better primary tumor delineation, thyroid cartilage and bone invasion. Furthermore, quantification algorithms allow measuring iodine concentration, reflecting the blood supply of a lesion indirectly.DECT enables acquiring images with lower radiation doses and iodine intravenous contrast load to obtain the same CT values. However, DECT uses ionizing radiation, which does not occur with MRI, and requires long post-processing times. Artifacts on iodine maps may be a potential source of pseudolesions. Besides, photon-counting CT scanners are a promising technique that may displace some DECT advantages.A review analyzing the current status of DECT applied to head and neck imaging from the scope of strengths, weaknesses, opportunities, and threatsanalysis would be very interesting to facilitate a realistic, fact-based, data-driven look of this technique.     

Thyroid cancer--indications and opportunities for positron emission tomography/computed tomography imaging

Although thyroid cancer is a comparatively rare malignancy, it represents the vast majority of endocrine cancers and its incidence is increasing. Most differentiated thyroid cancers have an excellent prognosis if diagnosed early and treated appropriately. Aggressive histologic subtypes and variants carry a worse prognosis. During the last 2 decades positron emission tomography (PET) and PET/computed tomography (CT), mostly with fluorodeoxyglucose (FDG), has been used increasingly in patients with thyroid cancers. Currently, the most valuable role FDG-PET/CT exists in the work-up of patients with differentiated thyroid cancer status post thyroidectomy who present with increasing thyroglobulin levels and a negative (131)I whole-body scan. FDG-PET/CT is also useful in the initial (post thyroidectomy) staging of high-risk patients with less differentiated (and thus less iodine-avid and clinically more aggressive) subtypes, such as tall cell variant and Hürthle cell carcinoma, but in particular poorly differentiated and anaplastic carcinoma. FDG-PET/CT may help in defining the extent of disease in some patients with medullary thyroid carcinoma and rising postoperative calcitonin levels. However, FDOPA has emerged as an alternate and more promising radiotracer in this setting. In aggressive cancers that are less amenable to treatment with (131)iodine, FDG-PET/CT may help in radiotherapy planning, and in assessing the response to radiotherapy, embolization, or experimental systemic treatments. (124)Iodine PET/CT may serve a role in obtaining lesional dosimetry for better and more rationale planning of treatment with (131)iodine. Thyroid cancer is not a monolithic disease, and different stages and histologic entities require different approaches in imaging and individualized therapy.     

Thyroid: nuclear medicine update

Nuclear medicine has been used in the evaluation and treatment of benign and malignant thyroid disease since the discovery of iodine 131 ((131)I) in the 1930s. Although traditional methods of imaging are routinely used, recent advancements such as SPECT/CT and PET/CT have greatly enhanced the ability of nuclear medicine to accurately detect and localize. Guidelines for the management of thyroid cancer continue to evolve, treatment regimens selected should balance the long-term risk of disease recurrence and cumulative risks of radiation exposure, and physicians should be aware of these updates and guidelines when caring for patients with thyroid disease.     

PET/CT imaging of thyroid cancer

Positron emission tomography (PET) is a highly sensitive, low invasive technology for cancer biology imaging. The role of F-18 FDG PET/CT in differentiated thyroid cancer (DTC) is well established, particularly in patients presenting with elevated Tg levels and negative radioactive iodine WBS. It has been demonstrated that F-18 FDG uptake represents less differentiated thyroid cancer cells or dedifferentiated cells and PET positive lesions are more likely to be resistant to I treatment. The uptake of F-18 FDG is related to tumor size, thyroid capsule invasion and histological variants with a poor prognosis. As in other cancers, early detection of recurrences improves outcomes and survival. I PET/CT can also be used to image the patients with DTC, similarly to I WBS. Compared with F-18 FDG PET/CT, its spatial resolution is only slightly degraded but increasing the imaging time reduces this difference. In addition, F-18 FDG PET/CT has been found helpful in the management of patients with anaplastic and medullary thyroid cancer. Other radiopharmaceuticals such as Ga-DOTATOC and F-18 DOPA may provide complimentary information to F-18 FDG PET/CT in the detection of recurrent thyroid cancer.     

Hepatic visualization on iodine-131 whole-body thyroid cancer scans

This study examines the frequency and significance of diffuse liver uptake on 131I whole-body thyroid cancer scans. Sixty whole-body scans on 27 patients with differentiated thyroid cancer were reviewed. Liver uptake was quantitated on another 21 studies (16 patients). Diffuse hepatic uptake was seen in 44% of patients and 35% of all the studies. It correlated best with the 131I dose administered (r = 0.733) and the product of the 131I percent radioactive iodine uptake (RAIU) and administered dose (r = 0.656), less well with the serum 131I protein bound iodine (r = 0.494) and the RAIU. This study demonstrates that liver visualization is more common than generally appreciated and is related to the 131I dose and indices of thyroid function although other factors may also play a role in liver visualization.     

日本福岛核电站事故对儿童甲状腺癌影响的研究进展

2011年3月,日本福岛发生核电站爆炸事故,大量放射性核素释放到环境中。尽管福岛事故释放的放射性核素¹³¹I的活度低于切尔诺贝利事故,但事故可能产生的对儿童甲状腺的影响以及其他健康效应,仍令人关注。本文简述了事故后福岛儿童甲状腺癌与辐射照射间关系的最新研究进展。事故后福岛县儿童甲状腺癌发病率与当地儿童接受外照射剂量间无明确关联,尚无明确证据证明辐射照射对儿童甲状腺产生负面影响,甲状腺癌发病率升高可能是过度筛查所致。     

Present and future of FDG-PET/CT in ovarian cancer

Integrated FDG-PET/CT has been used successfully for the diagnosis, staging, restaging, therapy monitoring and prognostic prediction of ovarian cancer as well as various other malignant tumors. Compared with conventional PET/non-contrast CT images, combined PET/contrast-enhanced CT images with intravenous iodine contrast medium and sufficient radiation dose may contribute to a more accurate diagnosis with higher confidence. In the future, tracers other than FDG and integrated PET/MRI will be realized. We herein review the place and role of FDG-PET/CT in the management of ovarian cancer, discussing its usefulness and limitations in the imaging of these patients.     

The Chernobyl accident and its consequences: update at the millennium

A marked increase in the incidence of papillary thyroid cancer in children has been documented in regions of the former Soviet Union most heavily contaminated by radioactive fallout from the Chernobyl nuclear power plant accident in April 1986. Accumulation of radioactive iodines by normal iodine trapping mechanisms resulted in significant radiation doses to the thyroid gland. Although it has long been known that thyroidal radiation resulted in nuclear and chromosomal abnormalities visible by light microscopy, modern molecular biology techniques are beginning to identify much smaller alterations in chromosomal coding sequences that are associated with malignant transformation. Although stable chromosomal abnormalities can be detected in Chernobyl-associated thyroid cancers, they are much less prevalent than in thyroid cancers developing after external beam irradiation. However, several unique chromosomal breakpoints have been described in radiation-associated thyroid cancers that are not commonly found in spontaneously occurring thyroid cancer. Furthermore, activation of specific subtypes of the ret/PTC tyrosine kinase oncogene appears to be more common in radiation-associated thyroid cancers than in spontaneous thyroid cancers. In summary, thyroid cancers developing in the aftermath of the Chernobyl accident provide a unique opportunity to search for chromosomal abnormalities that may be specific for radiation-induced thyroid cancer.     

SPECT/CT in the Treatment of Differentiated Thyroid Cancer

Single-photon emission computed tomography with integrated computed tomography (SPECT/CT) systems has been applied in a wide range of clinical circumstances, and differentiated thyroid cancer (DTC) is one of the most important indications of SPECT/CT imaging. In the treatment of DTC, SPECT/CT images have been reported to have many advantages over conventional planar whole-body scintigraphy based on its precise localization and characterization of abnormal foci of radioactive iodine (RAI) accumulation, influencing the staging, risk stratification, and clinical management as well as reader confidence. On the other hand, SPECT/CT has limitations including additional radiation exposure from the CT component, additional imaging time, and cost-related issues. Each SPECT/CT image acquired at different time points throughout the management of DTC may have a different clinical meaning and significance. This review article addresses the clinical usefulness of RAI SPECT/CT images acquired during the pre-ablation period, post-therapy period, and long-term follow-up period, respectively.     

The effect of gadolinium contrast media on radioiodine uptake by the thyroid gland

OBJECTIVE: Patients with thyroid cancer may require detailed anatomic imaging before 131I therapy. Imaging by contrast-enhanced CT is contraindicated because it may result in saturation of tissues with iodine, decreasing the avidity of thyroid or thyroid cancer cells to subsequent radioiodine for extended intervals. Gadolinium-enhanced MRI offers an alternative to CT for detailed anatomic imaging. However, it is not known whether gadolinium contrast affects uptake of iodine by the thyroid gland since lanthanides affect ion transport in a variety of ways. The objective of this project was to determine whether the gadolinium MRI contrast injection alters thyroid uptake of radioiodine. METHODS: Radioiodine uptake by the thyroid gland was measured at 6 h and 24 h after the oral administration of 100 microCi 123I-Na-I. Three to seven days later, a standard dose (20 mL) of Magnevist (gadolinium DTPA) was administered intravenously. Another capsule of 100 microCi 123I Na-I immediately was given orally, and 6-h and 24-h radioiodine uptake by the thyroid gland was again measured and compared to baseline values. RESULTS: There was no statistically significant difference in uptake of radioiodine uptake by the thyroid gland between baseline values and those acquired immediately after the administration of Magnevist. CONCLUSION: Contrast-enhanced MRI may be safely performed before contemplated determinations of thyroid uptake of radioiodine, 131I therapy for hyperthyroidism, and postsurgical 131I imaging and therapy for well-differentiated thyroid cancer.     

Study and implementation of a computerized program for personalized prescriptions for patients treated with radioiodine to be discharged]

INTRODUCTION: Iodine-131 (131I) therapy is widely used to treat some thyroid diseases such as hyperthyroidism and thyroid carcinoma. The discharge of a radioiodine treated patient is a potential problem for the radiation protection of the general population. To keep the absorbed dose to the general population as low as possible, patients are given some recommendations, on discharge usually a quite standard list of behaviors to avoid for an amount of time depending only on the administered activity. Thus, recommendations usually consider neither the individual kinetics of 131I nor disease type, while both factors account for major differences in iodine uptake and retention. We investigated the feasibility of customizing recommendations according to recent Euratom guidelines. MATERIAL AND METHODS: Individual 131I kinetics can be evaluated from previous work characterizing dose rate decay as a function of time for different thyroid diseases, together with measurements of iodine uptake or dose rate to the patient. Based on individual kinetics, the committed effective dose to the general population is calculated according to the kind of relationship with the patient, resulting in different amounts of time spent near him/her. RESULTS: The calculation procedure was implemented in a user-friendly software which requires input of few data and measurements to give each patient a customized list of precautions. Using the program on patient's discharge takes no longer than 10 minutes. The precautions are in good agreement with those reported in the literature. CONCLUSIONS: We have been using our program for nine months. Data show that most patients treated for thyroid cancer must follow the recommendations for a shorter time than hyperthyroid patients. The program is suitable for routine use in a nuclear medicine department.     

Computed tomography of the head: An experimental study to investigate the effectiveness of lead shielding during three scanning protocols

PurposeThe purpose of this experimental study, carried out in 2002, was to investigate the effectiveness of lead shielding during three scanning protocols for Computed Tomography (CT) head examinations.During CT, the thyroid is irradiated via scattered radiation outside the primary beam. Scientists have proved a definite link between thyroid cancer and radiation but have struggled to quantify the risks from low doses such as those in medical exposures. Children are known to be at higher risks from the effects of radiation than adults.MethodAn anthropomorphic phantom was used to simulate the patient. Shielding in the form of a standard lead thyroid shield was used due to the nature of the rotating X-ray beam involved with CT. Thermoluminescent detector chips were used to measure the approximate dose to the thyroid with and without the application of the shield.ResultsThe effectiveness of shielding varied with scanning technique, as did the thyroid dose due to scattered radiation. The lead shield significantly reduced the dose to the thyroid by 46–58% at the surface of the thyroid and by 37–44% within the thyroid tissue at 1 cm depth.ConclusionIn light of the increasing number of CT scanners, and the fact that head scans account for 50% of all CT examinations and 25% of the collective dose from CT to the UK population, it is important that all methods of dose reduction are considered. The use of shielding is a simple yet effective method of dose optimisation that has not been extensively investigated.     

Estimated risks of radiation-induced fatal cancer from pediatric CT

OBJECTIVE: In light of the rapidly increasing frequency of pediatric CT examinations, the purpose of our study was to assess the lifetime cancer mortality risks attributable to radiation from pediatric CT. MATERIALS AND METHODS: Organ doses as a function of age-at-diagnosis were estimated for common CT examinations, and estimated attributable lifetime cancer mortality risks (per unit dose) for different organ sites were applied. Standard models that assume a linear extrapolation of risks from intermediate to low doses were applied. On the basis of current standard practice, the same exposures (milliampere-seconds) were assumed, independent of age. RESULTS: The larger doses and increased lifetime radiation risks in children produce a sharp increase, relative to adults, in estimated risk from CT. Estimated lifetime cancer mortality risks attributable to the radiation exposure from a CT in a 1-year-old are 0.18% (abdominal) and 0.07% (head)-an order of magnitude higher than for adults-although those figures still represent a small increase in cancer mortality over the natrual background rate. In the United States, of approximately 600,000 abdominal and head CT examinations annually performed in children under the age of 15 years, a rough estimate is that 500 of these individuals might ultimately die from cancer attributable to the CT radiation. CONCLUSION: The best available risk estimates suggest that pediatric CT will result in significantly increased lifetime radiation risk over adult CT, both because of the increased dose per milliampere-second, and the increased lifetime risk per unit dose. Lower milliampere-second settings can be used for children without significant loss of information. Although the risk-benefit balance is still strongly tilted toward benefit, because the frequency of pediatric CT examinations is rapidly increasing, estimates that quantitative lifetime radiation risks for children undergoing CT are not negligible may stimulate more active reduction of CT exposure settings in pediatric patients.     

日本福岛第一核电站事故对儿童甲状腺的影响

2011年日本福岛县发生七级核事故,本文简述了事故后福岛县儿童甲状腺剂量估计、甲状腺结节或甲状腺囊肿和甲状腺癌发生情况的最新研究进展。结果提示,甲状腺结节和甲状腺囊肿发生率没有明显增加,有研究发现甲状腺癌发生率明显高于日本其他地区。有学者认为高发病率可能与研究中对照人群选择及筛查效应有关。此外,¹³²Te等短半衰期放射性核素对甲状腺剂量的贡献和甲状腺癌的发生发展有着不容忽视的作用。对核电站运行前后的连续监测及事故后健康评价具有重要意义。     

131I治疗Graves甲状腺功能亢进症中碳酸锂的应用

131I治疗Graves甲状腺功能亢进症(甲亢)的有效性取决于其在甲状腺内的滞留时间,且受治疗前抗甲状腺药物使用、肿大甲状腺容积和甲状腺24 h摄碘率等因素的影响.锂具有阻止有机碘和甲状腺激素自甲状腺内释出的作用而不影响甲状腺对131I的摄取,因此,131I治疗Graves甲亢前后辅以短程、小剂量碳酸锂,具有提高甲状腺...     

The effect of iodine uptake on radiation dose absorbed by patient tissues in contrast enhanced CT imaging: Implications for CT dosimetry

Objectives

To investigate the effect of iodine uptake on tissue/organ absorbed doses from CT exposure and its implications in CT dosimetry.

Methods

The contrast-induced CT number increase of several radiosensitive tissues was retrospectively determined in 120 CT examinations involving both non-enhanced and contrast-enhanced CT imaging. CT images of a phantom containing aqueous solutions of varying iodine concentration were obtained. Plots of the CT number increase against iodine concentration were produced. The clinically occurring iodine tissue uptake was quantified by attributing recorded CT number increase to a certain concentration of aqueous iodine solution. Clinically occurring iodine uptake was represented in mathematical anthropomorphic phantoms. Standard 120 kV CT exposures were simulated using Monte Carlo methods and resulting organ doses were derived for non-enhanced and iodine contrast-enhanced CT imaging.

Results

The mean iodine uptake range during contrast-enhanced CT imaging was found to be 0.02-0.46% w/w for the investigated tissues, while the maximum value recorded was 0.82% w/w. For the same CT exposure, iodinated tissues were found to receive higher radiation dose than non-iodinated tissues, with dose increase exceeding 100% for tissues with high iodine uptake.

Conclusions

Administration of iodinated contrast medium considerably increases radiation dose to tissues from CT exposure.

Key-points

? Radiation absorption ability of organs/tissues is considerably affected by iodine uptake ? Iodinated organ/tissues may absorb up to 100?% higher radiation dose ? Compared to non-enhanced, contrast-enhanced CT may deliver higher dose to patient tissues ? CT dosimetry of contrast-enhanced CT imaging should encounter tissue iodine uptake

     

Low-iodine diet revisited: importance in nuclear medicine imaging and management

PURPOSE: The need for a low-iodine diet (LID) to maximize the results of radioactive iodine uptake (RAIU), nuclear medicine thyroid scintigraphy, and ultimately treatment of thyroid cancer patients is widely accepted. Failure to follow the prescribed diet can alter RAIU results, thyroid scan findings, and poststudy management. OBJECTIVE: Provided is a case presentation that illustrates the need for adequate patient understanding and compliance with the LID. METHODS: We present the clinical history, laboratory values, and pertinent imaging of a 21-year-old woman with papillary thyroid cancer. The patient's post-thyroidectomy I-123 and 2 subsequent thyroid (I-123 and post-RAI ablation I-131) scintigraphy examinations are reviewed as well as the patient's urine iodine levels. RESULTS: In this case of a woman with papillary thyroid cancer, the nuclear medicine whole body and neck pinhole images revealed that compliance to an LID positively impacts the overall management. After an LID was followed, the patient's urine iodine level appropriately declined from the previously elevated level. Initial negative results on thyroid scintigraphy caused by noncompliance with the LID became positive when the patient adhered to the prescribed dietary regimen. CONCLUSION: An LID is an integral element in the management of differentiated thyroid cancer. Proper guidance and emphasis on the implementation of the diet needs to be provided to patients. Noncompliance may lead to false negative imaging results, misleading the medical professionals and patient. Potentially inadequate management of the patient's thyroid cancer may follow.     

Imaging of the thyroid in benign and malignant disease

The thyroid gland was one of the first organs imaged in nuclear medicine, beginning in the 1940s. Thyroid scintigraphy is based on a specific phase or prelude to thyroid hormone synthesis, namely trapping of iodide or iodide analogues (ie, Tc99m pertechnetate), and in the case of radioactive iodine, eventual incorporation into thyroid hormone synthesis within the thyroid follicle. Moreover, thyroid scintigraphy is a reflection of the functional state of the gland, as well as the physiological state of any structure (ie, nodule) within the gland. Scintigraphy, therefore, provides information that anatomical imaging (ie, ultrasound, computed tomography [CT], magnetic resonance imaging) lacks. Thyroid scintigraphy plays an essential role in the management of patients with benign or malignant thyroid disease. In the former, the structure or architecture of the gland is best demonstrated by anatomical or cross-sectional imaging, such as ultrasound, CT, or even magnetic resonance imaging. The role of scintigraphy, however, is to display the functional state of the thyroid gland or that of a clinically palpable nodule within the gland. Such information is most useful in (1) patients with thyrotoxicosis, and (2) those patients whose thyroid nodules would not require tissue sampling if their nodules are hyperfunctioning. In neoplastic thyroid disease, thyroid scintigraphy is often standard of care for postthyroidectomy remnant evaluation and in subsequent thyroid cancer surveillance. Planar radioiodine imaging, in the form of the whole-body scan (WBS) and posttherapy scan (PTS), is a fundamental tool in differentiated thyroid cancer management. Continued controversy remains over the utility of WBS in a variety of patient risk groups and clinical scenarios. Proponents on both sides of the arguments compare WBS with PTS, thyroglobulin, and other imaging modalities with differing results. The paucity of large, randomized, prospective studies results in dependence on consensus expert opinion and retrospective analysis with inherent bias. With a growing trend not to ablate low-risk patients, so that a PTS cannot be performed, some thyroid carcinoma patients may never have radioiodine imaging. In routine clinical practice, however, imaging plays a critical role in patient management both before and after treatment. Moreover, as evidenced by the robust flow of publications concerning WBS and PTS, planar imaging of thyroid carcinoma remains a topic of great interest in this modern age of rapidly advancing cross sectional and hybrid imaging with single-photon emission computed tomography, single-photon emission computed tomography/CT, and positron emission tomography/CT.     

Radioactive iodine therapy for malignant and benign thyroid disease: a Canadian national survey of physician practice

BACKGROUND: Radioactive iodine (as Na131I) has been used in the diagnosis and treatment of thyroid disease for more than 60 years, but the various treatment centres in Canada have different practice patterns. AIM: To determine whether there is a definable, nationwide pattern of practice which may be used to elucidate standards of practice and clarify some issues that arise when multiple care-givers are involved. METHODS: A survey questionnaire was mailed to all sites licensed by the Canadian Nuclear Safety Commission to administer Na131I for benign and malignant thyroid therapy. A second mailing was sent to non-responders. The questionnaire addressed the involvement of personnel: i.e., who prescribes, determines doses, obtains informed consent, counsels on radiation safety, administers the therapy, and follows the patient post-therapy. The survey also specifically addressed whether a nuclear medicine physician reviewed laboratory work or met with patients pre-therapy. RESULTS: The overall response rate was 60% (74/123) with representation from all Canadian provinces. The majority of respondents were physicians (78%). The data include 3447 benign thyroid therapies and 1202 malignant thyroid therapies. There are no significant regional differences in the average maximum dose administered for either benign or malignant thyroid therapies. The majority of therapies are administered in community and academic hospital settings. Endocrinologists most commonly prescribe Na131I for malignant thyroid therapies and nuclear medicine physicians for benign thyroid therapies. For all therapies nuclear medicine physicians most commonly obtain informed consent, determine the dose and provide radiation safety counselling. Nuclear medicine technologists most commonly administer the therapy and endocrinologists most commonly provide post-therapy follow-up. In the majority of centres, nuclear medicine physicians review the laboratory results for each patient's blood sample and meet with patients before therapy. CONCLUSIONS: Multiple health care specialists take part in Na131I therapy for both benign and malignant thyroid disease. In most centres, nuclear medicine physicians have major roles in the delivery of the treatments, including reviewing clinical and biochemical information. The findings of this study should provide reassurance to many centres and guidance to others to allow closer harmonization of practice.     

131I治疗分化型甲状腺癌术后患者辐射剂量预测模型的研究

目的 探讨131I治疗分化型甲状腺癌（DTC）术后患者全身辐射剂量代谢的影响因素,为辐射防护提供指导。 方法 回顾性分析2018年4至9月于3家三甲医院住院的72例DTC术后患者[男性27例、女性45例,年龄15~75（42.79±14.23）岁]的临床资料,其中同济大学附属第十人民医院23例、上海交通大学医学院附属仁济医院24例、华中科技大学同济医学院附属协和医院25例。根据服用131I后48 h全身辐射剂量是否达到安全标准将患者分为安全组（48 h全身辐射剂量≤23.30 μSv/h）和危险组（48 h全身辐射剂量>23.30 μSv/h）,比较各因素对全身辐射剂量代谢的影响。计量资料的组间比较采用成组t检验或Wilcoxon秩和检验;计数资料的组间比较采用卡方检验或Fisher确切概率法。对各变量进行单因素分析,对单因素分析中差异有统计学意义的变量采用多因素Logistic回归分析。以各单因素及多因素联合指标绘制受试者工作特征（ROC）曲线,评估其最佳临界值及诊断效能。 结果 危险组和安全组比较的单因素分析结果显示,甲状腺2 h摄碘率（t=?2.56,P=0.01）、24 h摄碘率（Z=?2.07,P=0.04）、游离三碘甲腺原氨酸（Z=?2.83,P=0.01）、游离甲状腺素（Z=?2.70,P=0.01）、甲状腺球蛋白（Tg）水平（χ2=6.80,P=0.01）、甲状腺超声提示是否存在甲状腺残留组织（Fisher确切概率法,P=0.03）等6个指标显著影响了131I治疗DTC术后患者的全身辐射剂量代谢。多因素Logistic回归分析结果显示,24 h摄碘率[OR=1.27（95%CI:1.03~1.57）]和Tg水平[OR=2.51（95%CI:1.21~5.20）]对全身辐射剂量代谢有影响（P=0.03、0.01）,24 h摄碘率和Tg水平越高的患者其48 h全身辐射剂量达到安全水平的可能性越低。24 h摄碘率+Tg水平（联合指标）诊断的ROC曲线下面积为0.76（95%CI:0.65~0.87）、灵敏度为94.87%、特异度为46.88%、最佳临界值为?0.71。 结论 24 h摄碘率和Tg水平是131I治疗DTC术后患者全身辐射剂量代谢的影响因素,利用这两个因素建立联合指标进行辐射剂量评估可为调整患者住院时长提供参考。