Radiation exposure and thyroid cancer: a review

How Many Imaging Studies Do Patients With Neuromuscular Early Onset Scoliosis (EOS) Receive?

BACKGROUND

Children with neuromuscular early onset scoliosis (EOS) receive numerous radiographic studies both from orthopaedic and other specialties. Ionizing radiation doses delivered by computed tomography (CT) are reportedly 100 times higher than conventional radiography. The purpose of this study was to evaluate the number of radiographic studies ordered for neuromuscular EOS patients during their care.

METHODS

Retrospective review at a tertiary children's hospital from January 2010 to June 2021 included all patients with neuromuscular EOS followed by an orthopaedic specialist for a minimum of 3 years. Patients were excluded if the majority of their nonorthopaedic care was provided by outside institutions.

RESULTS

Eighteen patients met inclusion criteria with mean follow up of 6.4±2.3 years. A total of 1312 plain radiographs and 35 CT scans were performed. Of the plain radiographs, 34.7% were ordered by orthopaedic providers and 65.3% (857/1312) were ordered by other providers. Of the CT scans, 4 were ordered by orthopaedic providers, while 88.5% (21/35) were ordered by other providers. An average of 74.7 (range: 29 to 124) radiographs and 1.9 (range: 0 to 9) CT scans ordered over the course of each patient's treatment for an average of 13.0±6.0 radiographs and 0.3 CT scans per year.

CONCLUSIONS

With an average of 75 radiographs and 1.9 CT scans performed per patient, consideration for steps to limit exposure to ionizing radiation should be made a particularly high priority in this unique subset of patients. This requires interdisciplinary coordination as 65% of the radiographs and over 80% of the CT scans were ordered by nonorthopaedic providers.

LEVEL OF EVIDENCE

Level III.

Update on radiation protection of the thyroid gland

In recent years, concern about the effects of ionizing radiation on exposed individuals has led to the need to regulate and quantify the use of diagnostic and therapeutic techniques. Geopolitical events in recent times have also increased the population's perception of insecurity regarding ionizing radiation, and we increasingly face patients reluctant to undergo certain types of scans in our nuclear medicine services and, albeit less frequently, in radiology services. This article aims to summarise the extent to which ionizing radiation is present in our daily lives and how diagnostic and therapeutic procedures can affect our health, particularly from the perspective of their effects on the thyroid gland, one of the body's most radiation-sensitive organs.

Estimation and comparison of the effective dose and lifetime attributable risk of thyroid cancer between males and females in routine head computed tomography scans: a multicentre study

INTRODUCTION

A significant number of head computed tomography (CT) scans are performed annually. However, due to the close proximity of the thyroid gland to the radiation field, this procedure can expose the gland to ionising radiation. Consequently, this study aimed to estimate organ dose, effective dose (ED) and lifetime attributable risk (LAR) of thyroid cancer from head CT scans in adults.

METHODS

Head CT scans of 74 patients (38 males and 36 females) were collected using three different CT scanners. Age, sex, and scanning parameters, including scan length, tube current-time product (mAs), pitch, CT dose index, and dose-length product (DLP) were collected. CT-Expo software was used to calculate thyroid dose and ED for each patient based on scan parameters. LARs were subsequently computed using the methodology presented in the Biologic Effects of Ionizing Radiation (BEIR) Phase VII report.

RESULTS

Although the mean thyroid organ dose (2.66 ± 1.03 mGy) and ED (1.6 ± 0.4 mSv) were slightly higher in females, these differences were not statistically significant compared to males (mean thyroid dose, 2.52 ± 1.31 mGy; mean ED, 1.5 ± 0.4 mSv). Conversely, there was a significant difference between the mean thyroid LAR of females (0.91 ± 1.35) and males (0.20136 ± 0.29) (P = 0.001). However, the influencing parameters were virtually identical for both groups.

CONCLUSIONS

The study's results indicate that females have a higher LAR than males, which can be attributed to higher radiation sensitivity of the thyroid in females. Thus, additional care in the choice of scan parameters and irradiated scan field for female patients is recommended.

Impact of beam collimation of z-overscanning on dose to the lens and thyroid gland in paediatric thoracic computed tomography imaging

BACKGROUND

Adaptive collimation reduces the dose deposited outside the imaged volume along the z-axis. An increase in the dose deposited outside the imaged volume (to the lens and thyroid) in the z-axis direction is a concern in paediatric computed tomography (CT).

OBJECTIVE

To compare the dose deposited outside the imaged volume (to the lens and thyroid) between 40-mm and 80-mm collimation during thoracic paediatric helical CT.

MATERIALS AND METHODS

We used anthropomorphic phantoms of newborns and 5-year-olds with 40-mm and 80-mm collimation during helical CT. We compared the measured dose deposited outside the imaged volume using optically stimulated luminescence dosimeters (OSLD) at the surfaces of the lens and thyroid and the image noise between the 40-mm and 80-mm collimations.

RESULTS

There were significant differences in the dose deposited outside the imaged volume (to the lens and thyroid) between the 40-mm and 80-mm collimations for both phantoms (P < 0.01).

CONCLUSION

Compared with that observed for 80-mm collimation in helical CT scans of the paediatric thorax, the dose deposited outside the imaged volume (to the lens and thyroid) was significantly lower in newborns and 5-year-olds with 40-mm collimation.

Organochlorine pesticides and risk of papillary thyroid cancer in U.S. military personnel: a nested case-control study

BACKGROUND

The effects of organochlorine pesticide (OCP) exposure on the development of human papillary thyroid cancer (PTC) are not well understood. A nested case-control study was conducted with data from the U.S. Department of Defense Serum Repository (DoDSR) cohort between 2000 and 2013 to assess associations of individual OCPs serum concentrations with PTC risk.

METHODS

This study included 742 histologically confirmed PTC cases (341 females, 401 males) and 742 individually-matched controls with pre-diagnostic serum samples selected from the DoDSR. Associations between categories of lipid-corrected serum concentrations of seven OCPs and PTC risk were evaluated for classical PTC and follicular PTC using conditional logistic regression, adjusted for body mass index category and military branch to compute odds ratios (OR) and 95% confidence intervals (CIs). Effect modification by sex, birth cohort, and race was examined.

RESULTS

There was no evidence of associations between most of the OCPs and PTC, overall or stratified by histological subtype. Overall, there was no evidence of an association between hexachlorobenzene (HCB) and PTC, but stratified by histological subtype HCB was associated with significantly increased risk of classical PTC (third tertile above the limit of detection (LOD) vs. Collapse

Key Words

• Hexachlorobenzene
• Hexachlorocyclohexane
• Organochlorine pesticides
• Papillary thyroid cancer

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MESH Headings

• Male
• Humans
• Female
• Military Personnel
• Thyroid Cancer, Papillary/epidemiology
• Hexachlorobenzene
• Case-Control Studies
• Pesticides
• Hydrocarbons, Chlorinated
• Thyroid Neoplasms/chemically induced
• Thyroid Neoplasms/epidemiology
• Hexachlorocyclohexane

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Grants

• R01ES020361 NIH HHS
• R01ES020361 NIH HHS
• National Institutes of Health
• Murtha Cancer Center Research Program
• Oak Ridge Associated Universities
• National Cancer Institute Intramural Research Program

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Affiliation(s)

Jennifer A Rusiecki Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Room E-2009, Bethesda, MD, 20814, USA.
Jordan McAdam Murtha Cancer Center Research Program, 4494 North Palmer Road, Bethesda, MD, USA Henry M. Jackson Foundation for the Advancement of Military Medicine, 1401 Rockville Pike, Rockville, MD, USA
Hristina Denic-Roberts Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Room E-2009, Bethesda, MD, 20814, USA Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN, USA
Andreas Sjodin Division of Laboratory Sciences, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
Mark Davis Division of Laboratory Sciences, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
Richard Jones Division of Laboratory Sciences, Centers for Disease Control and Prevention (CDC), Atlanta, GA, USA
Thanh D Hoang Division of Endocrinology, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
Mary H Ward Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
Shuangge Ma Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
Yawei Zhang Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA Department of Cancer Prevention and Control, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China

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Should we reconsider blocking the thyroid for 123 I-Ioflupane studies in elderly patients: quantifying radiation dose to the unblocked thyroid and implications for clinical practice

OBJECTIVES

To measure the absorbed dose to the thyroid in patients injected with 123 I-Ioflupane where the thyroid was not blocked with prophylaxis to investigate whether thyroid blocking should be limited to younger patients. This risk from the additional absorbed dose to the thyroid was then compared to the risk from iodine overdose through ingestion of the iodide prophylaxis, resulting in iodine-induced hyper/hypothyroidism (IIH).

METHODS

A cohort of patients (n = 30) who did not receive thyroid prophylaxis underwent static thyroid imaging 3 h after 123 I-Ioflupane administration. The measured thyroidal uptake of free 123 I was then extrapolated to peak uptake time (24 h post-administration). This value was used to calculate cumulated activity in the thyroid and thus thyroid-thyroid absorbed dose D(rthy←rthy ) using the relevant S-value in the MIRD method.

RESULTS

Mean D(rthy←rthy ) was found to be 13.6 mGy with an SD of 8.8 mGy; this would contribute an additional 0.5 mSv to the effective dose.

CONCLUSION

ARSAC recommends in its Notes for Guidance prophylactic thyroid blocking if the absorbed dose to the thyroid is >50 mGy; the maximum thyroid dose in this study cohort was 36.3 mGy. With risk from IIH and its associated cardiac complications increasing with age, this study suggests that iodide prophylaxis with 123 I-Ioflupane should be reconsidered for elderly patient.

Health-Related Complications during Follow-Up and Their Impact on Blood Cancer Survivors: Results from the "Aftercare in Blood Cancer Survivors" (ABC) Study

INTRODUCTION

Blood cancer survivors are at increased risk for medical complications.

METHODS

Our questionnaire-based study involved 1,551 blood cancer survivors with a ≥3-year interval since the last intense treatment. Its goal was to quantify health-related complications during follow-up and assess their impact on the patients' lives.

RESULTS

A total of 20.4% of the responding survivors reported a disease relapse, most often in indolent lymphomas. Second primary malignancies occurred in 14.1%, primarily in lymphoma and allogeneic transplantation survivors. The most frequent malignancy was basal cell carcinoma of the skin, but myeloid malignancies, melanoma, bladder, head-and-neck, and thyroid cancer also appeared disproportionately frequent. An increased infection rate was reported by 43.7%, most often after allogeneic transplantation. New cardiovascular diseases were reported by 30.2%, with a high rate of thromboembolic events in multiple myeloma (MM) and myeloproliferative diseases. Polyneuropathies were reported by 39.1%, most often by survivors with a history of MM or aggressive lymphoma. Disease relapse was perceived as the highest burden, followed by second primary malignancy, increased infection frequency, and polyneuropathy. In each area investigated, the range of perceived severities was wide.

CONCLUSIONS

Health-related complications are frequent during blood cancer follow-up, with significant repercussions on the patients' lives.

Evolving approaches in paediatric thyroid cytopathology: A review

The guidelines for the workup of thyroid nodules have been established in adult populations and secondarily applied to paediatric populations. In particular, The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is commonly applied to both adult and paediatric thyroid nodules. However, as paediatric nodules have distinct molecular drivers and behavioural trajectories, there is renewed interest in diagnostic and management strategies that are paediatric specific. Here, we review key differences between paediatric and adult thyroid cancer and recent literature evaluating the use of TBSRTC in paediatric populations.

Orthopaedic surgeons' knowledge and practice of radiation safety when using fluoroscopy during procedures: A narrative review

OBJECTIVES

The fluoroscopy environment poses a potential occupational radiation exposure risk to theatre personnel. Risks can be mitigated with effective application of radiation protection knowledge and methods. This review aimed to determine the link between orthopaedic surgeon's knowledge and the use of appropriate safety methods when using fluoroscopy.

KEY FINDINGS

A keyword search of three databases discovered six articles, totalling 2209 orthopaedic surgeons, who completed surveys to assess knowledge on various aspects of radiation safety and training. Participants had varying levels of experience. Moreover 1981 participants always wore a lead gown (89 %), while only 1052 participants wore thyroid protection (47 %). 449 participants (20 %) received some form of training.

CONCLUSION

Although surveys asked a range of questions it appeared that there was low knowledge of the ALARP principles. Usage of protective equipment is a legal requirement and thus was observed throughout, however, there were a number of incidences of disregarding some protective measures. Although there appeared to be limited knowledge surrounding radiation protection measures and lack of training provided, no clear link was demonstrated between compliance with protective methods and knowledge of the risks.

IMPLICATIONS FOR PRACTICE

Formal and continuous training should be provided for the enhancement of knowledge to ensure the safety of all staff and help prevent the long-term effects of ionising radiation when using fluoroscopy.

An organ-effective modulation for non-contrast chest computed tomography imaging: effect on image quality and thyroid exposure reduction

We investigate the efficacy of organ-effective modulation (OEM) technique for thyroid dose reduction among various body habitus and its impact on image quality in chest non-contrast computed tomography (CT). We prospectively enrolled 64 patients who underwent non-contrast chest CT from January to May 2022. The skin-absorbed radiation dose over the thyroid (Dthyroid) was obtained using a thermoluminescence dosemeter. Signal-to-noise ratio and image noise was also quantitatively assessed. In subjective analyses, two radiologists independently evaluated images based on a 5-point scale. The OEM group showed a markedly decrease in Dthyroid when compared with the non-OEM group (p < 0.05). No significant difference was observed regarding the image noise (p < 0.05), except for the ventral air space. The subjective scores of two radiologists showed no significant differences between the non-OEM and OEM groups. OEM can effectively reduce the radiation exposure of thyroid without compromising on image quality in non-contrast chest CT.

Temporal trends of thyroid cancer between 2010 and 2019 in Asian countries by geographical region and SDI, comparison with global data

Objective

This study aims to describe temporal trends of thyroid cancer (ThC) from 2010 to 2019, in Asian countries by geographical region and sociodemographic index, compared with global data.

Method

Annual case data and age-standardized rates (ASRs) of epidemiological indicators of ThC cancer data were collected from the 2019 Global Burden of Disease (GBD) study from 2010 to 2019 in 49 countries and territories in Asia. The relative difference (%) between years was used to show comparative variations of ASRs for the indicators studied. The female/male ratio was calculated by dividing female ASRs by male ASRs. Also, these rates were compared between the age group ≥70 years old and younger age groups.

Results

In 2019, more than 50% of ThC cases and deaths occurred in Asian countries. A total of 53% of ThC patients lived in Asia and more than 60% of the global burden of ThC was imposed on Asian countries. From 2010 to 2019, incidences, deaths, prevalence cases, and DALYs number of ThC cancer increased over 1.28-, 1.26-, 1.3-, and 1.2-fold, in Asia, respectively. During this period, the age-standardized incidence rate (ASIR) and the age-standardized prevalence rate (ASPR) of ThC cancer increased by 5% and 8%, respectively, while the age-standardized death rate (ASDR) and the age-standardized DALYs rate (DALYs ASR) of ThC cancer decreased by 6% and 4%, respectively. These trends are different from what happens in other continents. In 2019, age-specific incidence, death, prevalence, and DALY cases of ThC cancer were peaking at 50-54, 75-79, 50-54, and 55-59 years, respectively. In 2019, the highest ASIR and ASPR of ThC cancer was observed in high-income Asia Pacific countries and the highest ASDR and DALYs ASR in Southeast Asia countries. Only high-income Asia Pacific countries experienced a decreasing trend in ASIR and ASPR from 2010 to 2019. ASDR and DALYs ASR have the highest decreasing trend in high-income Asia Pacific. In 2019, among high SDI Asian countries, the Republic of Korea had the highest ASIR and ASPR, and Brunei Darussalam had the highest ASDR and DALYs ASR. The highest ASIR, ASDR, ASPR, and DALY ASR of ThC cancer was found in Lebanon and Malaysia (high-middle SDIs), Vietnam (middle SDIs), and Cambodia and Palestine (low-middle SDIs). Among low SDI Asian countries, Pakistan had the highest ASIR, ASDR, ASPR, and DALY ASR of ThC cancer. All indicators for most countries were higher in women than men.

Conclusion

More than half of the burden of thyroid cancer is imposed on the residents of the Asian continent. Although the incidence and prevalence of this cancer in Asian countries is lower than that of the world, America, and Europe, the highest rate of death from thyroid cancer occurs in Asia and they witness the highest burden of the disease. Therefore, it seems that implementing early detection strategies and increasing access to treatment facilities in Asia is one of the necessities of thyroid cancer control in its residents.

Radiation exposure doses to the surgical team during hip surgery is significantly higher during lateral imaging than posteroanterior imaging: a cadaveric simulation study

BACKGROUND

Fluoroscopy is indispensable when determining appropriate and effective interventions in orthopedic surgery. On the other hand, there is growing concern about the health hazards of occupational radiation exposure. The aim of this cadaveric simulation study was to measure radiation exposure doses to the surgical team during hip surgery.

METHODS

We reproduced the intraoperative setting of hip surgery using 7 fresh frozen cadavers (5 male, 2 female) to simulate patients and mannequins to simulate the surgeon, scrub nurse, and anesthesiologist. Six real-time dosimeters were mounted at sites corresponding to the optic lens, thyroid gland, chest, gonads, foot, and hand on each mannequin. The radiation exposure dose to each team member was measured during posteroanterior and lateral fluoroscopic imaging.

RESULTS

Radiation exposure doses to the surgeon were significantly higher during 3 min of lateral imaging than during 3 min of posteroanterior imaging at the optic lens (8.1 times higher), thyroid gland (10.3 times), chest (10.8 times), and hand (19.8 times) (p = 0.018, p = 0.018, p = 0.018, and p = 0.018, respectively). During lateral imaging, the radiation doses to the nurse were 0.16, 0.12, 0.09, 0.72, and 0.38 times those to the surgeon at the optic lens, thyroid, chest, gonads, and foot, respectively. The radiation dose to the anesthesiologist was zero at all anatomic sites during posteroanterior imaging and very small during lateral imaging.

CONCLUSIONS

Radiation exposure dose was significantly higher during lateral imaging up to 19.8 times comparing to the posteroanterior imaging. It is effective to reduce the lateral imaging time for reducing the intraoperative radiation exposure. In addition, appropriate distance from fluoroscopy resulted in very low exposure for nurses and anesthesiologists. Surgeon should pay attention that surgical staff do not get closer than necessary to the irradiation field.

Hashimoto's Thyroiditis and the Risk of Papillary Thyroid Cancer in Children

The association between Hashimoto's thyroiditis (HT) and pediatric thyroid cancer is controversial. Most studies examining this connection have been based on adults, and larger studies in children are lacking. We performed a retrospective study of all sequential pediatric patients who underwent a thyroidectomy for a neoplasm at our institution over a twenty-year period in order to explore the link between HT and pediatric thyroid cancer. A total of 153 patients, median age 16.5 (interquartile range [IQR] 14.2-18.3) years, underwent thyroid surgery for a neoplasm. Patients were mainly female (80%) and White (84%). Median follow-up was 58.6 (IQR 20.7-105.4) months. Thirty-five (23%) patients had HT. Patients who underwent thyroid surgery and had HT were more likely to harbor a malignant neoplasm (p = 0.05); specifically, papillary thyroid carcinoma (PTC, p = 0.02). There was a difference in the distribution of HT among the subtypes of PTC (p = 0.03). Despite this, there was no difference in terms of survival between patients with/without HT. In conclusion, children with a thyroid malignancy, specifically, PTC, are more likely to have HT. The association between HT and pediatric PTC appears to be subtype-specific but does not seem to affect patient survival.

Global incidence and prevalence of differentiated thyroid cancer in childhood: systematic review and meta-analysis

Objective

Differentiated thyroid cancer (DTC) is rare in childhood and adolescence although it represents the most frequent endocrine malignancy in this population. DTC includes both papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC). Most pediatric DTCs are PTCs, while FTCs are rare. To date, no systematic reviews on the global epidemiology of pediatric and adolescent DTC have been published. This systematic review and meta-analysis aims to estimate the overall incidence and prevalence of DTCs in patients aged 0-19 years.

Methods

The systematic research was conducted from January 2000 to December 2021 through MEDLINE via PubMed, Cochrane Library, and Embase databases. Two separate meta-analyses were performed for PTC and FTC.

Results

After the selection phase, a total of 15 studies (3,332 screened) met the inclusion criteria and are reported in the present systematic review. Five studies were conducted in Europe, five in North America, two in South America, one in Asia, one reported data for 49 countries and territories across the five continents, and one from both the USA and Africa. Most of the studies (n = 14) reported data obtained from national registries, and only one provided information collected from hospital medical records. Beyond the actual trend over time, our study reported a pooled global incidence rate (IR) of PTC and FTC in the pediatric age of 0.46 (95% CI: 0.33-0.59) and 0.07 (95% CI: 0.02-0.12) per 100,000 person-years, respectively. The highest IRs were recorded among Caucasian girls, and the lowest in black or other races/ethnicities.

Conclusion

Our data confirm that DTC in the pediatric population is a rare condition. The pooled IRs of the studies included in this meta-analysis are ~0.5 for PTC, which is the most common histological type when both genders and all age groups are considered. The implementation of a prospective international registry on pediatric DTC, as part of the wider European Registries for Rare Endocrine Conditions, has been recently proposed. In addition to providing relevant information on the clinical behavior of this rare disease, standardization of data collection will be pivotal to fill current gaps and allow an accurate estimation of the real incidence and risk factors of DTC.

Thyroid Ultrasound Screening in Childhood Cancer Survivors following Radiotherapy

INTRODUCTION

Childhood cancer survivors (CCS) are at risk for radiotherapy (RT) late effects, including second malignancies. Optimal screening for differentiated thyroid cancer (DTC) in CCS post-RT remains controversial. We assessed the outcome of thyroid ultrasound (US) surveillance in CCS exposed to RT.

METHODS

306 CCS were surveilled with thyroid US between 2002-2021. Surveillance was dependent on age at the time of primary diagnosis, interval from receipt of RT, and individual provider. Thyroid US, clinicopathologic features, and outcomes were described. Cutpoints of CCS RT age associated with varying risk of nodule presentation were explored. The selected cutpoints were used to define age categories, which were then used to compare thyroid nodule-related outcomes. Risk factors for thyroid nodule(s) were evaluated using multivariate logistic regression (odds ratio [OR] [95% confidence interval]).

RESULTS

The most common CCS diagnoses were leukemia (32%), CNS tumor (26%), and neuroblastoma (18%). Patients received TBI (45%) and/or RT to craniospinal (44%), chest (11%), and neck regions (6%). About 49% (n = 150) of patients had thyroid nodule(s). Forty-four patients underwent surgery, and 28 had DTC: 19 with American Thyroid Association (ATA) low-risk classification, 2 with ATA intermediate-risk, and 7 with ATA high-risk disease. Age cutpoint analyses identified cutpoints 3 and 10; hence, ≤3, >3 to ≤10, and >10 years were used. Of the 9 patients with intermediate- or high-risk disease, 8 were ≤10 years and 1 was >10 years at the time of RT. Female sex (OR = 1.62 [1.13-2.12] p = 0.054) and greater interval between RT and first US (OR = 1.10 [1.04-1.16] p = 0.001) were independent risk factors for nodule presentation.

CONCLUSIONS

Thyroid US surveillance may be beneficial for CCS exposed to RT at younger ages (≤10 years) for earlier detection of DTC, prior to developing advanced metastatic disease.

Measurement of Occupational Eye and Thyroid Radiation Doses in Pediatric Interventional Cardiologists at a Tertiary Hospital

Background Advances in imaging techniques have led to increased utilization of imaging devices in catheterization laboratories. Invasive surgical procedures for cardiac disorders have been largely replaced by fluoroscopic cardiac catheterization. With this increase, concerns and risks associated with exposure to ionizing radiation among interventional cardiologists are growing. This study aims to measure and compare the occupational doses to the eye lens and thyroid of pediatric interventional cardiologists during different procedures in the catheterization laboratory and its significance. Methodology In this study, cardiologists wore bandanas with attached dosimeters to measure the absorbed doses to the eyes and thyroid gland. The dosimeters were collected for reading. The procedure types were also collected. In addition, the total fluoroscopy time and tube voltage of the biplane machine were measured. SPSS version 23 (IBM Corp., Armonk, NY, USA) was used to analyze the data. The characteristics of the study sample were described using simple counts and percentages, whereas means and standard deviations were used for continuous variables. Statistical significance was set at p-values <0.05. Results A total of 93 procedures were evaluated. The mean absorbed doses for all 93 procedures in both eyes and thyroid were 0.09 mGy and 0.08 mGy, respectively. A significant difference was found between the left and right eye measurements (p = 0.034), with higher doses administered to the left eye. However, no significant difference was observed between the right and left thyroid doses (p = 0.281). Significant correlations were found between the eye and thyroid doses and the procedure type (p = 0.02 and p = 0.009, respectively). Conclusions A significant amount of radiation was measured in the measurements of both organs. In addition, radiation dose measurements varied between different types of procedures. Our current results indicate the importance and necessity of applying the radiation protection concept of dose optimization.

Update on Radiation Safety in the Cath Lab - Moving Toward a "Lead-Free" Environment

Radiation exposure in the cardiac catheterization laboratory (CCL) is an occupational hazard that predisposes health care workers to the development of adverse health effects such as cataracts, cancer, and orthopedic injury. To mitigate radiation exposure, personal protective shielding as well as permanently installed shields reduces these adverse effects. Yet, heavy protective lead aprons and poor ergonomics required for positioning movable shields remain barriers to a safer environment. Recent innovations to enhance personal protective equipment and revolutionize fixed shielding systems will permit the CCL team to work in a personal "lead-free" environment, markedly reducing occupational hazards. The purpose of this review is to update the status and future of radiation protection in the CCL.

Identification of crucial genes involved in thyroid cancer development

BACKGROUND

A malignancy of the endocrine system, one of the most common types, is thyroid cancer. It is proven that children who receive radiation treatment for leukemia or lymphoma are at a heightened risk of thyroid cancer due to low-dose radiation exposure throughout childhood. Several factors can increase the risk of thyroid cancer (ThyCa), such as chromosomal and genetic mutations, iodine intake, TSH levels, autoimmune thyroid disorders, estrogen, obesity, lifestyle changes, and environmental contaminants.

OBJECTIVES

The study aimed to identify a specific gene as an essential candidate for thyroid cancer progression. We might be able to focus on developing a better understanding of how thyroid cancer is inherited.

METHODS

The review article uses electronic databases such as PubMed, Google Scholar, Ovid MEDLINE, Embase, and Cochrane Central. The most frequently associated genes with thyroid cancer found on PubMed were BAX, XRCC1, XRCC3, XPO5, IL-10, BRAF, RET, and K-RAS. To perform an electronic literature search, genes derived from DisGeNET: a database of gene-disease associations, including PRKAR1A, BRAF, RET, NRAS, and KRAS, are used.

CONCLUSION

Examining the genetics of thyroid cancer explicitly emphasizes the primary genes associated with the pathophysiology of young and older people with thyroid cancer. Developing such gene investigations at the beginning of the thyroid cancer development process can identify better outcomes and the most aggressive thyroid cancers.

Evaluation of radiation dose in multi-slice computed tomography protocols of head and neck regions

In head and neck computed tomography (CT) imaging, the optimisation of radiation dose is crucial due to the presence of radio-sensitive organs. This study aimed to evaluate the radiation dose in multi-slice CT for head and neck examinations. Volume CT dose index, dose length product and effective dose (E) were assessed for 10 head and neck CT scans performed on 292 adult patients (mean age 49.2 ± 15.9 y). The study resulted in median E values of 0.82, 1.62, 2.43, 0.93, 1.70, 0.83, 3.55, 6.25, 2.19 and 5.26 mSv, respectively, for sinuses (non-contrast (NC)), sinuses (NC) and contrast-enhanced (CE), petrous bone (PTB)/internal auditory meatus (IAM) (NC + CE), PTB/IAM (NC), orbit (NC + CE), orbit (NC), brain with the orbit (NC), brain CT angiography (CTA) subtraction, neck (NC) and brain/neck (NC). Furthermore, the overall radiation doses of this institution were found to be below the values suggested by similar studies. However, optimisation of the dose is required for brain CTA.

Inadvertent Thyroid Radiation During Computed Tomography of the Chest: A Retrospective Study

Background

The thyroid, along with the breast, lung, and bone marrow, is among the most radiosensitive organs. This study aims to assess the rate of unnecessary radiation exposure to the thyroid gland in patients who had chest Computed Tomography (CT) at a large teaching hospital.

Method

Hospital-based retrospective cross-sectional study on 1,306 patients who underwent chest CT from July 2018 to January 2019. Thyroid gland inclusion along with the CT dose of the studies was evaluated. Data was collected by evaluating chest CT scans from Picture Archive and Communication System (MedWeb).

Result

Out of 1306 patients, who had Chest CT scans intravenous iodinated contrast media was used in 95.4% of the CT scans. The thyroid was included in 99.8% of the scans, out of which 76.9% included the whole thyroid gland. Among the patients who had previous CT scans, 75.3% had one previous scan and 24.7% had two previous scans. DLP (Dose Length Product) in mGycm was lower in females (360.33±32) compared to males (426.45±378.4). The lowest DLP value was observed in the pediatric patients in the age range of 1-5 years which was 146.83, while the highest was observed among those above 18 years of age with mean DLP of 418.31.

Conclusion

The majority of chest CT scans unnecessarily include the whole thyroid gland, which is one of the most sensitive organs for radiation-induced effects. Authors recommend optimized technique for chest scans to avoid future impacts.

Estimating exposure to extremely low frequency magnetic fields near high-voltage power lines and assessment of possible increased cancer risk among Slovenian children and adolescents

BACKGROUND

Some previous research showed that average daily exposure to extremely low frequency (ELF) magnetic fields (MF) of more than 0.3 or 0.4 μT could potentially increase risk of childhood leukaemia.

MATERIALS AND METHODS

To allow calculations of ELF MF around high voltage (HV) power lines (PL) for the whole Slovenia, a new three-dimensional method including precision terrain elevation data was developed to calculate the long-term average ELF MF. Data on population of Slovenian children and adolescents and on cancer patients with leukaemia's aged 0-19 years, brain tumours at age 0-29, and cancer in general at age 0-14 for a 12-year period 2005-2016 was obtained from the Slovenian Cancer Registry.

RESULTS

According to the large-scale calculation for the whole country, only 0.5% of children and adolescents under the age of 19 in Slovenia lived in an area near HV PL with ELF MF density greater than 0.1 μT. The risk of cancer for children and adolescents living in areas with higher ELF MF was not significantly different from the risk of their peers.

CONCLUSIONS

The new method enables relatively fast calculation of the value of low-frequency magnetic fields for arbitrary loads of the power distribution network, as the value of each source for arbitrary load is calculated by scaling the value for nominal load, which also enables significantly faster adjustment of calculated estimates in the power distribution network.

Self-reported causes of cancer among 6881 survivors with 6 tumour types: results from the PROFILES registry

OBJECTIVE

Our aim was to describe and compare self-reported causal attributions (interpretations of what caused an illness) among cancer survivors and to assess which sociodemographic and clinical characteristics are associated with them.

METHODS

Data from five population-based PROFILES registry samples (i.e. lymphoma (n = 993), multiple myeloma (n = 156), colorectal (n = 3989), thyroid (n = 306), endometrial (n = 741), prostate cancer (n = 696)) were used. Causal attributions were assessed with a single question.

RESULTS

The five most often reported causal attributions combined were unknown (21%), lifestyle (19%), biological (16%), other (14%), and stress (12%). Lymphoma (49%), multiple myeloma (64%), thyroid (55%), and prostate (64%) cancer patients mentioned fixed causes far more often than modifiable or modifiable/fixed. Colorectal (33%, 34%, and 33%) and endometrial (38%, 32%, and 30%) cancer survivors mentioned causes that were fixed, modifiable, or both almost equally often. Colorectal, endometrial, and prostate cancer survivors reported internal causes most often, whereas multiple myeloma survivors more often reported external causes, while lymphoma and thyroid cancer survivors had almost similar rates of internal and external causes. Females, those older, those treated with hormonal therapy, and those diagnosed with prostate cancer were less likely to identify modifiable causes while those diagnosed with stage 2, singles, with ≥2 comorbid conditions, and those with endometrial cancer were more likely to identify modifiable causes.

CONCLUSION

In conclusion, this study showed that patients report both internal and external causes of their illness and both fixed and modifiable causes. This differsbetween the various cancer types.

IMPLICATIONS FOR CANCER SURVIVORS

Although the exact cause of cancer in individual patients is often unknown, having a well-informed perception of the modifiable causes of one's cancer is valuable since it can possibly help survivors with making behavioural adjustments in cases where this is necessary or possible.

Induction of epithelial-mesenchymal transition in thyroid follicular cells is associated with cell adhesion alterations and low-dose hyper-radiosensitivity

BACKGROUND

Epithelial-mesenchymal transition (EMT) is associated with altered cellular adhesion. We previously demonstrated that cellular adhesion influences Low-dose Hyper-Radiosensitivity (HRS) in a variety of tumor cells. However, the relationship of low-dose HRS with the phenotypic plasticity incurred by EMT during the neoplastic transformation remains to be elucidated.

OBJECTIVE

To investigate whether acquisition of EMT phenotype during progressive neoplastic transformation may affect low-dose radiation sensitivity.

METHODS

Primary thyroid cells obtained from a human cystic thyroid nodule were first subjected to nutritional stress. This yielded immortalized INM-Thy1 cell strain, which was further treated with either multiple γ-radiation fractions (1.5 Gy each) or repetitive cycles of 3-methylcholanthrene and phorbol-12-myristate-13-acetate, yielding two progressive transformants, viz., INM-Thy1R and INM-Thy1C. Morphological alterations, chromosomal double-minutes, cell adhesion proteins, anchorage dependency, tumorigenicity in nude mice and cellular radiosensitivity were studied in these strains.

RESULTS

Both transformants (INM-Thy1R, INM-Thy1C) displayed progressive tumorigenic features, viz., soft agar colony growth and solid tumor growth in nude mice, coupled with features of epithelial-mesenchymal transition and activated Wnt pathway. Incidentally, the chemical-induced transformant (INM-Thy1C) displayed a prominent HRS (αs/αr = 29.35) which remained unaffected at high cell density. However, the parental (INM-Thy1) cell line as well as radiation-induced transformant (INM-Thy1R) failed to show this hypersensitivity.

CONCLUSION

The study shows that induction of EMT in thyroid follicular cells may accompany increased susceptibility to low-dose ionizing radiation, which was attenuated by adaptive resistance acquired during radiation-induced transformation.

Global thyroid cancer incidence trend and age-period-cohort model analysis based on Global Burden of Disease Study from 1990 to 2019

Background

In view of the rapid increase in the incidence of thyroid cancer (TC) and the spread of overdiagnosis around the world, the quantitative evaluation of the effect of age, period and birth cohort on the incidence of TC, and the analysis of the role of different factors in the incidence trend can provide scientific basis and data support for the national health departments to formulate reasonable prevention and treatment policies.

Methods

The study collated the global burden disease study data of TC incidence from 1990 to 2019, and used APC model to analyze the contribution of age, period and birth cohort to the incidence trend of TC.

Results

There was an obvious unfavorable upward trend in terms of age and cohort effect all over the world. Since 2007, the growth rate of risk slowed down and the risk in female even decreased since 2012, which mainly contributed to the developed countries. In all SDI countries, 2002 is the dividing point of risk between male and female. In 2019, The global age-standardized incidence rate (ASIR) of TC in the 5 SDI countries all showed a significant upward trend, with the largest upward trend in the middle SDI countries.

Conclusion

The trend of rapid increase in the incidence of TC has begun to slow down, but the global incidence of TC has obvious gender and regional/national heterogeneity. Policy makers should tailor specific local strategies to the risk factors of each country to further reduce the burden of TC.

Thyroid Carcinoma: A Review for 25 Years of Environmental Risk Factors Studies

Environmental factors are established contributors to thyroid carcinomas. Due to their known ability to cause cancer, exposure to several organic and inorganic chemical toxicants and radiation from nuclear weapons, fallout, or medical radiation poses a threat to global public health. Halogenated substances like organochlorines and pesticides can interfere with thyroid function. Like phthalates and bisphenolates, polychlorinated biphenyls and their metabolites, along with polybrominated diethyl ethers, impact thyroid hormones biosynthesis, transport, binding to target organs, and impair thyroid function. A deeper understanding of environmental exposure is crucial for managing and preventing thyroid cancer. This review aims to investigate the relationship between environmental factors and the development of thyroid cancer.

Molecular Landscape of Pediatric Thyroid Cancer: A Review

Thyroid carcinomas (TC) are rare in the pediatric population; however, they constitute the most common endocrine malignancy. Despite some similarities with adult carcinomas, they have distinct clinical behavior and responses to therapy due to their unique pathology and molecular characteristics. The age cut-off used for defining the pediatric age group has been variable across different studies, and the universally accepted recommendations influence accurate interpretation of the available data. Moreover, factors such as radiation exposure and germline mutations have greater impact in children than in adults. Papillary TC is the most common and the most evaluated pediatric TC. Others, including follicular, poorly differentiated and medullary carcinomas, are rarer and have limited available literature. Most studies are from the West. Asian studies are primarily from Japan, with few from China, India, Saudi Arabia and Republic of Korea. This review provides a comprehensive account of the well-established and novel biomarkers in the field, including point mutations, fusions, miRNA, and thyroid differentiation genes. Familial and syndromic associations are also discussed. Current management guidelines for pediatric patients are largely derived from those for adults. An awareness of the molecular landscape is essential to acknowledge the uniqueness of these tumors and establish specific diagnostic and therapeutic guidelines.

Thyroid nodules in children and adolescents: Investigation and management

Clinically detectable thyroid nodules are less common in children than adults. However, they are associated with an increased risk of malignancy. Therefore, thorough evaluation of paediatric thyroid nodules is necessary, and an understanding of the features associated with a higher risk of malignancy is important to guide management and referral. Thyroid cancer in children differs significantly from that seen in adults in terms of genetics, presentation, response to treatment and prognosis. Children often present with more advanced disease, but the vast majority have excellent long-term prognosis. Evaluation and management of thyroid nodules and thyroid cancer require a multidisciplinary team approach and involvement of specialists with experience in this field. This review summarises investigative pathways for thyroid nodules in children and outlines current management strategies for paediatric thyroid nodules and cancer.

Radiation in Gastroenterology

The benefit of radiation is immense in the field of gastroenterology. Radiation is used daily in different gastrointestinal imaging and diagnostic and therapeutic interventional procedures. Radiotherapy is one of the primary modalities of treatment of gastrointestinal malignancies. There are various modalities of radiotherapy. Radiotherapy can injure malignant cells by directly damaging DNA, RNA, proteins, and lipids and indirectly by forming free radicals. External beam radiation, internal beam radiation and radio-isotope therapy are the major ways of delivering radiation to the malignant tissue. Radiation can also cause inflammation, fibrosis, organ dysfunction, and malignancy. Patients with repeated exposure to radiation for diagnostic imaging and therapeutic procedures are at slightly increased risk of malignancy. Gastrointestinal endoscopists performing fluoroscopy-guided procedures are also at increased risk of malignancy and cataract formation. The radiological protection society recommends certain preventive and protective measures to avoid side effects of radiation. Gastrointestinal complications related to radiation therapy for oncologic processes, and exposure risks for patients and health care providers involved in diagnostic or therapeutic imaging will be discussed in this review.

Assessment of thyroid gland hormones and ultrasonographic abnormalities in medical staff occupationally exposed to ionizing radiation

BACKGROUND

Ionizing radiation (IR) is high-energy radiation that has the potential to displace electrons from atoms and break chemical bonds. It has the ability to introduce mutations, DNA strand breakage, and cell death. Being a radiosensitive organ, exposure of the thyroid gland to IR can lead to significant changes in its function.

AIM OF THE WORK

Was to measure the levels of thyroid hormones panel and ultrasonography abnormalities in medical staff occupationally exposed to IR.

SUBJECTS AND METHODS

A total of 120 subjects were divided into three main groups: Group I: radiation-exposed workers occupationally exposed to radioiodine (131I) (n = 40), Group II: radiation-exposed workers occupationally exposed to X-ray (n = 40), and Group III: non-exposed healthy professionals matched in age and sex with the previous groups (n = 40). Thyroid hormones panel including free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), anti-thyroperoxidase antibodies (anti-TPO), and thyroglobulin (Tg) were measured. Thyroid ultrasonography was performed. Oxidative stress markers such as malondialdehyde (MDA), hydrogen peroxide (H2O2), and total antioxidant capacity (TAC) were measured.

RESULTS

Group I had significantly higher fT3 levels than the control group. fT3 levels were considerably higher, while TSH was substantially lower in group II participants than in the control group. Tg was markedly lower in radiation-exposed workers. However, anti-TPO levels in radiation-exposed workers were significantly higher than in the control group. MDA and H₂O₂ were substantially higher; TAC was significantly lower in radiation-exposed workers compared to the control group. According to ultrasonographic examination, thyroid volume and the percentage of thyroid nodules in all radiation workers were significantly higher than in the control group.

CONCLUSION

Despite low exposure doses, occupational exposure to IR affects the thyroid hormones and links with a higher likelihood of developing thyroid immune diseases.

Case report: Triple whammy: Synchronous radiotherapy induced glioblastoma multiforme and papillary thyroid cancer following nasopharyngeal carcinoma

Secondary malignancies following radiotherapy are well documented, with an estimated incidence of 5%. These may manifest as carcinomas, gliomas, or sarcomas within the previous radiation field. Glioblastoma multiforme following radiotherapy for nasopharyngeal carcinoma is an uncommon occurrence and carries a poor prognosis, whereas papillary thyroid carcinoma following radiotherapy is well documented, though the exact incidence is not well documented. The occurrence of synchronous radiotherapy-induced malignancy over both sites has not been described in the literature before. We describe a middle-aged gentleman diagnosed with glioblastoma multiforme and papillary thyroid carcinoma 6 years after radiotherapy for nasopharyngeal carcinoma. Though our case is the first reported case of a synchronous tumour of its nature, it is likely that such cases are under-reported. Long-term vigilance for loco-regional radiotherapy-induced secondary malignancies is a must, and the presence of a second distinct secondary malignancy must be entertained.

Pharmacological protection of the thyroid gland against radiation damage from radioactive iodine labeled compounds in children: a systematic review

Purpose

There is currently no consensus on which protective strategy is most effective to prevent I-131 uptake in the thyroid during medical interventions in children. We aimed to collect the best available evidence to determine which pharmacological intervention is most effective in protecting the thyroid gland from damage by radioactive iodine (RAI).

Methods

Literature searches were performed using PubMed, Embase, OLDMEDLINE, and the Cochrane Central Register of Controlled Trials. Only original studies were included (1950–2022). Studies comparing pharmacological prevention of the thyroid against RAI uptake or occurrence of hypothyroidism, thyroid nodule or thyroid cancer were included. Included studies were graded according to the Grading of Recommendations Assessment, Development and Evaluation considerations. Pharmacological interventions were compared for effectiveness on reduction of thyroidal intake or relevant clinical thyroidal outcomes.

Results

Forty studies were included. Quality of included studies was low and many different outcome variables were used, making meta-analysis impossible. In 81% of studies, the pharmacological intervention could not prevent RAI uptake or thyroid damage. The administration of potassium iodide (KI) 1 h before exposure to RAI seemed most effective to reduce thyroidal uptake, however, hypothyroidism was reported in up to 64% as well as several cases of thyroid carcinoma. The combination of KI, thyroxine and thiamazole reduced RAI uptake and occurrence of hypothyroidism; yet, after follow-up of 9 years, still 50% of patients developed hypothyroidism. KI with potassium perchlorate showed hypothyroidism to occur in up to 12% of patients after short follow-up time.

Conclusions

The lack of well-designed studies impairs making strong recommendations on the optimal way to prevent thyroid damage when using radioactive coupled ligands for medical interventions. To improve the protection of the thyroid against radiation damage by I-131, well-designed randomized clinical trials with sufficient follow-up time, comparing new protective strategies’ effects on valid and well-defined thyroid outcomes are needed.

A nested case-control study of serum polychlorinated biphenyls and papillary thyroid cancer risk among U.S. military service members

BACKGROUND AND OBJECTIVES

Although polychlorinated biphenyls (PCBs) were banned decades ago, populations are continuously exposed to PCBs due to their persistence and bioaccumulation/biomagnification in the environment. Results from limited epidemiologic studies linking PCBs to thyroid cancer have been inconclusive. This study aimed to investigate the association between individual PCBs and PCB mixture and papillary thyroid cancer (PTC), the most common thyroid cancer histologic subtype.

METHODS

We carried out a nested case-control study including 742 histologically confirmed PTC cases diagnosed in 2000-2013 and 742 individually matched controls among U.S. military service members. Pre-diagnostic serum samples that were collected on average nine years before PTC diagnosis were used to measure PCB congeners by gas chromatography isotope dilution high resolution mass spectrometry (GC/ID-HRMS). Conditional logistic regression, Bayesian kernel machine regression (BKMR), and weighted quantile sum (WQS) regression were employed to estimate the association between single PCB congeners as well as their mixture and PTC.

RESULTS

Four PCB congeners (PCB-74, PCB-99, PCB-105, PCB-118) had significant associations and dose-response relationships with increased risk of PTC in single congener models. When considering the effects from all measured PCBs and their potential interactions in the BKMR model, PCB-118 showed positive trends of association with PTC. Increased exposure to the PCB congeners as a mixturewas also associated with an increased risk of PTC in the WQS model, with the mixture dominated by PCB-118, followed by PCB-74 and PCB-99. One PCB congener, PCB-187, showed an inverse trend of association with PTC in the mixture analysis.

DISCUSSION

This study suggests that exposure to certain PCBs as well as a mixture of PCBs were associated with an increased risk of PTC. The observed association was mainly driven by PCB-118, and to a lesser extent by PCB-74 and PCB-99. The findings warrant further investigation.

Simulations of radioiodine exposure and protective thyroid blocking in a new biokinetic model of the mother-fetus unit at different pregnancy ages

In the case of nuclear incidents, radioiodine may be released. After incorporation, it accumulates in the thyroid and enhances the risk of thyroidal dysfunctions and cancer occurrence by internal irradiation. Pregnant women and children are particularly vulnerable. Therefore, thyroidal protection by administering a large dose of stable (non-radioactive) iodine, blocking radioiodide uptake into the gland, is essential in these subpopulations. However, a quantitative estimation of the protection conferred to the maternal and fetal thyroids in the different stages of pregnancy is difficult. We departed from an established biokinetic model for radioiodine in pregnancy using first-order kinetics. As the uptake of iodide into the thyroid and several other tissues is mediated by a saturable active transport, we integrated an uptake mechanism described by a Michaelis–Menten kinetic. This permits simulating the competition between stable and radioactive iodide at the membrane carrier site, one of the protective mechanisms. The Wollf–Chaikoff effect, as the other protective mechanism, was simulated by adding a total net uptake block for iodide into the thyroid, becoming active when the gland is saturated with iodine. The model’s validity was confirmed by comparing predicted values with results from other models and sparse empirical data. According to our model, in the case of radioiodine exposure without thyroid blocking, the thyroid equivalent dose in the maternal gland increases about 45% within the first weeks of pregnancy to remain in the same range until term. Beginning in the 12th pregnancy week, the equivalent dose in the fetal thyroid disproportionately increases over time and amounts to three times the dose of the maternal gland at term. The maternal and fetal glands’ protection increases concomitantly with the amount of stable iodine administered to the mother simultaneously with acute radioiodine exposure. The dose–effect curves reflecting the combined thyroidal protection by the competition at the membrane carrier site and the Wolff–Chaikoff effect in the mother are characterized by a mean effective dose (ED₅₀) of roughly 1.5 mg all over pregnancy. In the case of the fetal thyroid, the mean effective doses for thyroid blocking, taking into account only the competition at the carrier site are numerically lower than in the mother. Taking into account additionally the Wolff–Chaikoff effect, the dose–effect curves for thyroidal protection in the fetus show a shift to the left over time, with a mean effective dose of 12.9 mg in the 12th week of pregnancy decreasing to 0.5 mg at term. In any case, according to our model, the usually recommended dose of 100 mg stable iodine given at the time of acute radioiodine exposure confers a very high level of thyroidal protection to the maternal and fetal glands over pregnancy. For ethical reasons, the possibilities of experimental studies on thyroid blocking in pregnant women are extremely limited. Furthermore, results from animal studies are associated with the uncertainties related to the translation of the data to humans. Thus model-based simulations may be a valuable tool for better insight into the efficacy of thyroidal protection and improve preparedness planning for uncommon nuclear or radiological emergencies.

Surgical outcomes in survivors of childhood cancer undergoing thyroidectomy: A single-institution experience

BACKGROUND

Childhood cancer survivors (CCS) are at increased risk for thyroid disease, and many require definitive management with thyroid surgery. Despite this, there is limited evidence on surgical outcomes among CCS. We sought to evaluate postoperative outcomes at our institution among CCS undergoing thyroid surgery compared to patients without a history of primary childhood malignancy.

PROCEDURE

Medical records were reviewed for 638 patients treated at the Children's Hospital of Philadelphia Pediatric Thyroid Center between 2009 and 2020. Rates of surgical complications, including recurrent laryngeal nerve (RLN) paralysis and hypoparathyroidism, among CCS were compared to patients with sporadic/familial thyroid cancer, Graves' disease, and other benign thyroid conditions. Operative time and intraoperative parathyroid hormone levels were also evaluated.

RESULTS

There were no significant differences in long-term surgical complication rates, such as permanent RLN paralysis and hypoparathyroidism, between CCS and patients without a history of primary childhood malignancy (all p > .05). For all surgical outcomes, there were no significant differences in complication rates when CCS were compared to those undergoing surgery for sporadic/familial thyroid cancer or Graves' disease (all p > .05). CCS with benign final pathology had significantly higher rates of transient hypoparathyroidism compared to patients with benign thyroid conditions (p < .001).

CONCLUSIONS

Our study suggests that CCS are not at higher risk of long-term complications from thyroid surgery when treated by high-volume surgeons within a multidisciplinary team.

Seaweed and Iodine Intakes and SLC5A5 rs77277498 in Relation to Thyroid Cancer

BACKGRUOUND

This study aims to elucidate the associations among dietary seaweed (gim and miyeok/dashima) and iodine intakes, the rs77277498 polymorphism of the SLC5A5 gene codifying the sodium/iodine symporter, and thyroid cancer risk in a Korean population.

METHODS

We conducted a case-control study of 117 thyroid cancer cases and 173 controls who participated in the Cancer Screenee Cohort between 2002 and 2014 at the National Cancer Center, Korea. The amount of seaweed and iodine consumption (g/day) was estimated using the residual energy adjustment method. We calculated odds ratios (ORs) and their 95% confidence intervals (CIs) using a multivariable logistic regression model for the separate and combined effect of dietary iodine-based intake and SLC5A5 polymorphism (rs77277498, C>G) on thyroid cancer.

RESULTS

Dietary gim and iodine intakes were inversely associated with thyroid cancer, with ORs of 0.50 (95% CI, 0.30 to 0.83) and 0.57 (95% CI, 0.35 to 0.95), respectively, whereas the associations for dietary miyeok/dashima and total seaweed intakes were not significant. However, compared with individuals carrying the C/C genotype of the rs77277498 polymorphism with a low intake of all dietary factors, those carrying the G allele with a high intake had a lower risk of thyroid cancer, with ORs of 0.25 (95% CI, 0.10 to 0.56), 0.31 (95% CI, 0.12 to 0.77), 0.26 (95% CI, 0.10 to 0.62), and 0.30 (95% CI, 0.12 to 0.73) for the consumption of gim, miyeok/dashima, total seaweed, and iodine, respectively.

CONCLUSION

In summary, our results supported the evidence of the protective effects of dietary gim and iodine intake against thyroid cancer risk, and this association can be strengthened by SLC5A5 rs77277498 genotypes.

Adverse Radiation Therapy Effects in the Treatment of Head and Neck Tumors

Whether used as a single modality or as part of a combined approach, radiation therapy (RT) plays an essential role in the treatment of several head and neck malignancies. Despite the improvement in radiation delivery techniques, normal structures in the vicinity of the target area remain susceptible to a wide range of adverse effects. Given their high incidence, some of these effects are referred to as expected postradiation changes (eg, mucositis, sialadenitis, and edema), while others are considered true complications, meaning they should not be expected and can even represent life-threatening conditions (eg, radionecrosis, fistulas, and radiation-induced neoplasms). Also, according to their timing of onset, these deleterious effects can be divided into four groups: acute (during RT), subacute (within weeks to months), delayed onset (within months to years), and very delayed onset (after several years).The authors provide a comprehensive review of the most important radiation-induced changes related to distinct head and neck sites, focusing on their typical cross-sectional imaging features and correlating them with the time elapsed after treatment. Radiologists should not only be familiar with these imaging findings but also actively seek essential clinical data at the time of interpretation (including knowledge of the RT dose and time, target site, and manifesting symptoms) to better recognize imaging findings, avoid pitfalls and help guide appropriate management. ^© RSNA, 2022.

Predictive factors for thyroid complications after radiation therapy-data from a cohort of cancer patients closely followed since they were irradiated

INTRODUCTION

Cancer survivors are at an increased risk of adverse outcomes, including thyroid neoplasms, given the high radiosensitivity of this gland. The aim of this study is to assess the incidence and timeframe of thyroid complications in cancer patients, followed systematically since their radiation therapy, and to identify risk factors for the development of hypothyroidism and thyroid cancer.

METHODS

We performed a retrospective study, including 282 subjects, who received neck, craniospinal, or total body irradiation (TBI). Patients were grouped into four primary diagnostic clusters: leukaemia, Hodgkin's disease, central nervous system, and head and neck tumours.

RESULTS

Hypothyroidism was observed in 56.7% of patients, on average 6.8 ± 5.9 years after the treatment. Neck and craniospinal irradiation presented a 3.5-fold increased risk for the development of hypothyroidism compared to TBI. Papillary thyroid cancer was diagnosed in 8.5% of the patients, on average, 18.5 ± 4.9 years after radiotherapy (RT). Female gender, younger age, and lower irradiation doses were independently associated with thyroid cancer development.

CONCLUSION

Our study provides useful information about the risk of hypothyroidism and thyroid cancer after RT, as it was performed in a cohort of patients closely followed since the oncological therapies, and, thus, may give new insights into the follow-up management of these patients.

Molecular profiling of papillary thyroid carcinomas in healthcare workers exposed to low dose radiation at the workplace

PURPOSE

Exposure to ionizing radiation, especially during childhood, is a well-established risk factor for thyroid cancer. The vast majority of radiation-induced cancers are papillary carcinomas (PTCs). These tumors typically have gene fusions in contrast to point mutations prevalent in sporadic PTCs. The aim of this study was to investigate the molecular profiles of PTC patients with workplace exposure to ionizing radiation.

METHODS

A retrospective review of 543 patients who underwent surgery with diagnosis of PTC was performed. A cohort of nine healthcare specialists previously exposed to radiation sources during their professional practice was selected and analyzed using the ThyroSeq mutation panel for point mutations and gene fusions associated with thyroid cancer.

RESULTS

The molecular analysis of surgical samples of PTCs was informative and revealed genetic alterations in five patients. BRAF V600E was found in four (67%) cases whereas RET/PTC1 fusion in one (17%) and one sample (17%) was wild type for point mutations and fusions. One sample completely failed molecular analysis while two others were negative for genes fusions but failed DNA analysis; these three samples were excluded.

CONCLUSIONS

In this limited cohort of healthcare workers exposed to low dose of ionizing radiation at the workplace and developed PTC, the molecular profiling determined BRAF V600E point mutation as the most common event, arguing against the role of workplace radiation exposure in the etiology of these tumors.

Thyroid cancer under the scope of emerging technologies

The vast majority of thyroid cancers originate from follicular cells. We outline outstanding issues at each step along the path of cancer patient care, from prevention to post-treatment follow-up and highlight how emerging technologies will help address them in the coming years. Three directions will dominate the coming technological landscape. Genomics will reveal tumoral evolutionary history and shed light on how these cancers arise from the normal epithelium and the genomics alteration driving their progression. Transcriptomics will gain cellular and spatial resolution providing a full account of intra-tumor heterogeneity and opening a window on the microenvironment supporting thyroid tumor growth. Artificial intelligence will set morphological analysis on an objective quantitative ground laying the foundations of a systematic thyroid tumor classification system. It will also integrate into unified representations the molecular and morphological perspectives on thyroid cancer.

Obesity and Thyroid Cancer Risk: An Update

Thyroid cancer (TC) is the most common endocrine malignancy worldwide and its incidence has increased dramatically in recent years. In parallel, the prevalence of overweight and obesity has also increased, suggesting a possible link between these two diseases. Indeed, low-grade chronic inflammation, altered cytokine levels, insulin resistance, oxidative stress, and hormonal changes that occur in obese patients are all factors that contribute to the occurrence and growth of TC. In this review, the most recent evidence supporting the potential role of the mechanisms linking obesity to TC will be discussed.

Environmental and social determinants of thyroid cancer: A spatial analysis based on the Geographical Detector

INTRODUCTION

Thyroid cancer has increased sharply in China in recent years. This change may be attributable to multiple factors. The current study aimed to explore the environmental and social determinants of thyroid cancer.

METHODS

Incidence data from 487 cancer registries in 2016 were collected. Eight factors were considered, namely, air pollution, green space, ambient temperature, ultraviolet radiation, altitude, economic status, healthcare, and education level. A geographical detector (measured by q statistic) was used to evaluate the independent and interactive impact of the eight factors on thyroid cancer.

RESULTS

Social factors, especially economic status and healthcare level (q > 0.2), were most influential on thyroid cancer.Ultraviolet radiation, air pollution, and temperature had more impact on women, while green space and altitude had more influence on men. Enhanced effects were observed when two factors interacted. Spatially, economic status, healthcare, and air pollution were positively associated with thyroid cancer, while education level, green space, and altitude were negatively related to thyroid cancer.

CONCLUSION

The socio-environmental determinants and spatial heterogeneity of thyroid cancer were observed in this study. These findings may improve our understanding of thyroid cancer epidemiology and help guide public health interventions.

The Iodine Rush: Over- or Under-Iodination Risk in the Prophylactic Use of Iodine for Thyroid Blocking in the Event of a Nuclear Disaster

Iodine is an essential element for the production of thyroid hormones (THs). Both deficient and excess iodine intakes may precipitate in adverse thyroidal events. Radioactive iodine (RI) is a common byproduct of nuclear fission processes. During nuclear emergencies RI may be released in a plume, or cloud, contaminating the environment. If inhaled or ingested, it may lead to internal radiation exposure and the uptake of RI mainly by the thyroid gland that absorbs stable iodine (SI) and RI in the same way. A dose of radiation delivered to the thyroid gland is a main risk factor for the thyroid cancer development. The SI prophylaxis helps prevent childhood thyroid cancer. The thyroid gland saturation with prophylactic SI ingestion, reduces the internal exposure of the thyroid by blocking the uptake of RI and inhibiting iodide organification. However, negative impact of inadequate SI intake must be considered. We provide an overview on the recommended iodine intake and the impact of SI and RI on thyroid in children and adolescents, discussing the benefits and adverse effects of the prophylactic SI for thyroid blocking during a nuclear accident. The use of SI for protection against RI may be recommended in cases of radiological or nuclear emergencies, moreover the administration of iodine for prophylactic purposes should be cautious. Benefits and risks should also be considered according to age. Adverse effects from iodine administration cannot be excluded. Precise indications are mandatory to use the iodine for thyroid blocking. Due to this natural adaption mechanism it's possible to tolerate large doses of iodine without clinical effects, however, a prolonged assumption of the iodine when not needed can be dangerous and may precipitate in severe thyroidal and non-thyroidal negative effects.

Single neonatal irradiation induces long-term gene expression changes in the thyroid gland, which may be involved in the tumorigenesis

Exposure to ionizing radiation in childhood has been recognized as a risk factor for thyroid cancer. We previously demonstrated that neonatal X-irradiation induced specific deformation of the thyroid follicles. Here, we further analyzed this model to understand the possible relationship with thyroid carcinogenesis. Wistar rats were subjected to cervical X-irradiation at different ages of 1–8 weeks old and at different doses of 1.5–12 Gy. For tumor promotion, rats were fed with an iodine-deficient diet (IDD). In cervically X-irradiated neonatal rats, the size of thyroid follicles decreased, accompanied by an increase in the number of TUNEL-positive cells. Fas and Lgals3 mRNA levels increased, while Mct8 and Lat4 expressions decreased. The co-administration of IDD induced the proliferation and the upregulation in Lgals3 expression, resulting in thyroid adenoma development at 28 weeks post-exposure. Our data demonstrated that single neonatal X-irradiation induced continuous apoptotic activity in the thyroid with the long-term alternation in Fas, Mct8, Lat4, and Lgals3 mRNA expressions. Some of these changes were similar to those induced by IDD, suggesting that neonatal X-irradiation may partially act as a thyroid tumor promoter. These radiation-induced thyroidal changes may be enhanced by the combined treatment with IDD, resulting in the early development of thyroid adenoma.

Facing Thyroid Nodules in Paediatric Patients Previously Treated with Radiotherapy for Non-Thyroidal Cancers: Are Adult Ultrasound Risk Stratification Systems Reliable?

Simple Summary

The risk of thyroid nodules harbouring cancer has been evaluated, in adults, using specific ultrasound criteria. However, it is unclear whether such evaluation can be translated in paediatric patients. In this study, we tested the effectiveness of three known risk evaluation systems in children with thyroid nodules and with a history of radiation exposure. We found that these systems are reliable in confirming or ruling out cancer in most cases, except when evaluating very small nodules (<1 cm). For these reasons, these risk criteria should be adopted to account for the reduced size of malignant lesions when evaluating paediatric subjects.

Abstract

Thyroid nodule ultrasound-based risk stratification systems (US-RSSs) have been successfully used in adults to predict the likelihood of malignancies. However, their applicability to the paediatric population is unclear, especially in children with a history of radiation exposure, who are at a higher cancer risk. We tested the efficacy of three US-RSSs in this setting by retrospectively applying three classification systems (ACR-TIRADS, ATA and EU-TIRADS) to all paediatric patients referred for thyroid nodules and with a radiation exposure history. We compared the results with a reference standard (pathology or 36-month follow-up); sensitivity, specificity, positive and negative predictive values (PPV and NPV) and accuracy were calculated. A total of 52 patients were included; fourteen of them (27%) had papillary thyroid cancer (PTC) at the final histology. No significant differences across the US-RSSs were detected; specificity (range 95–97%) and NPV (range 88–93%) were particularly elevated. However, ACR-TIRADS, ATA and EU-TIRADS did not indicate the need for a biopsy in six (42.8%), seven (50%) and eight (57%) cases of PTC; in five cases, this lack of indication was due to a small (<1 cm) nodule size. In conclusion, US-RSSs show a high NPV and specificity in paediatric patients, whereas the cytology indication could be improved by reconsidering the dimensional criterion.

Risk of Benign and Malignant Thyroid Disorders in Subjects Treated for Paediatric/Adolescent Neoplasia: Role of Morphological and Functional Screening

Background: Patients treated for paediatric/adolescent (P/A) neoplasia have a high incidence of both benign and malignant thyroid diseases. Given the high incidence of sequelae, literature data show a clinical benefit of morpho-functional thyroid screening in paediatric/adolescent cancer survivors and a careful lifetime follow-up. Patients and methods: The incidence of thyroid alterations was evaluated in a consecutive series of 343 patients treated with chemotherapy (CHE) and radiotherapy (RTE) or only with CHE for P/A tumours between 1976 and 2018 (mean age at time of primary paediatric malignancy 7.8 ± 4.7 years). All patients underwent thyroidal morpho-functional evaluation between 2000 and 2019. Results: 178 patients (51.9%) were treated only with CHE and 165 (48.1%) with CHE+RTE. A functional and/or structural thyroid disease was diagnosed in 147 (42.5%; 24.2% in CHE and 62.4% in CHE+RTE group; p = 0.0001). Of note, 71 (20.7%) patients with no evidence of disease at first evaluation developed a thyroid alteration during the follow-up. Primitive hypothyroidism was diagnosed in 54 patients (15.7%; 11.2% in CHE vs. 20.6% in CHE+RTE group; p = 0.01) and hyperthyroidism in 4. Sixty-three patients developed thyroid nodules (18.4%; 4.0% in CHE and 14.1% in CHE+RTE group; p < 0.001); thyroid cancer was diagnosed in 30 patients (8.7%; 4.5% in CHE and 12.4% in CHE + RTE group; p = 0.007). Conclusions: In patients treated with CHE+RTE, the prevalence of hypothyroidism and nodular pathology, both malignant and benign, were significantly greater than in patients treated with CHE. However, also in the CHE group, the frequency of thyroid disease is not negligible and the pathogenetic mechanisms remain to be clarified. Our data suggest the clinical benefit of morpho-functional thyroid screening in P/A cancer survivors.