scholarly journals Estimated Effective Lifetime Risks of Radiation-Induced Thyroid Cancer in Computed Tomography (CT) Brain Examination

2021 ◽  
Vol 50 (11) ◽  
pp. 3365-3372
Author(s):  
Rekha Ganesan ◽  
Muhammad Ikhmal Naim Mohd Hilal ◽  
Iza Nurzawani Che Isa ◽  
Norhashimah Norsuddin ◽  
Khadijah Mohd Nassir ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Thyroid Cancer ◽  
Biological Effects ◽  
Lifetime Risk ◽  
Effective Lifetime ◽  
Multiple Exposures ◽  
Percentage Difference ◽  
Radiation Induced ◽  
Radiosensitive Organs ◽  
Risk Of Cancer

Thyroid is one of the most radiosensitive organs in the human body. Although the scanning range of brain computed tomography (CT) does not include lower neck region, there is possibility for thyroid to be irradiated due to scattered radiation because of its location near to the external beam collimation. The objective of this study was to evaluate effective lifetime risk of radiation-induced thyroid cancer in young adults following brain CT examination. A total of 306 patient data within the age range between 18 and 39 years old were retrospectively analysed. Absorbed dose of the thyroid organ was obtained through the input of data using WAZA- ARI v2. Effective lifetime risk was calculated by multiplying equivalent dose of the thyroid organ with the lifetime attributable cancer risk adapted from Biological Effects in Ionising Radiation (BEIR) Report V11. The effective lifetime risks were recorded as 0.45 ± 0.70 per 100 000 and 0.93 ± 1.52 per 100 000 for single and multiple exposures, respectively. In terms of gender, woman data (0.99 ± 0.76; 1.95 ± 2.15) were found higher as compared to man data (0.13 ± 0.39; 0.35 ± 0.45) for both single and multiple exposure. The percentage difference of effective lifetime risks between single and multiple exposures was up to 107%. The effective lifetime risk noted in this study may be low, however, the long-term risk of cancer development should be considered. This study serves as preliminary reference when revising clinical protocol especially in those involving repeated exposures in young adult patients. Future study should include other radiosensitive organs exploring the effective lifetime risk of radiation induced cancer following CT procedure.

scholarly journals Determine Cumulative Radiation Dose and Lifetime Cancer Risk in Marfan Syndrome Patients Who Underwent Computed Tomography Angiography of the Aorta in Northeast Thailand: A 5-Year Retrospective Cohort Study

Tomography ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 120-130
Author(s):  
Narumol Chaosuwannakit ◽  
Phatraporn Aupongkaroon ◽  
Pattarapong Makarawate
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
Cancer Risk ◽  
Lifetime Risk ◽  
Surveillance Imaging ◽  
Radiation Induced Cancer ◽  
Cumulative Radiation Dose ◽  
Radiation Induced ◽  
The Mean ◽  
Risk Of Cancer

Objective: To evaluate computed tomography angiography (CTA) data focusing on radiation dose parameters in Thais with Marfan syndrome (MFS) and estimate the distribution of cumulative radiation exposure from CTA surveillance and the risk of cancers. Methods: Between 1st January 2015 and 31st December 2020, we retrospectively evaluated the cumulative CTA radiation doses of MFS patients who underwent CTA at Khon Kaen University Hospital, a leading teaching hospital and advanced tertiary care institution in northeastern Thailand. We utilized the Radiation Risk Assessment Tool (RadRAT) established at the National Cancer Institute in Bethesda, Maryland, to evaluate the risk of cancer-related CTA radiation. Results: The study recruited 29 adult MFS patients who had CTA of the aorta during a 5-year study period with 89 CTA studies. The mean cumulative CTDI vol is 21.5 ± 14.68 mGy, mean cumulative DLP is 682.2 ± 466.7 mGy.cm, the mean baseline future risk for all cancer is 26,134 ± 7601 per 100,000, and the excess lifetime risk for all cancer is 2080.3 ± 1330 per 100,000. The excess lifetime risk of radiation-induced cancer associated with the CTA surveillance study is significantly lower than the risk of aortic dissection or rupture and lower than the baseline future cancer risk. Conclusions: We attempted to quantify the radiation-induced cancer risk from CTA surveillance imaging performed for MFS patients in this study, with all patients receiving a low-risk cumulative radiation dose (less than 1 Gy) and all patients having a low excessive lifetime risk of cancer as a result of CTA. The risk–benefit decision must be made at the point of care, and it entails balancing the benefits of surveillance imaging in anticipating rupture and providing practical, safe treatment, therefore avoiding morbidity and mortality.

scholarly journals Assessment of Thyroid Cancer Risk After Cervical Computed Tomography: The Impact of Bismuth Shielding

2021 ◽  
Vol 10 (2) ◽  
pp. 70-74
Author(s):  
Hamid Ghaznavi ◽  
Zeinab Momeni ◽  
Sadegh Ghaderi
Keyword(s):  
Computed Tomography ◽  
Thyroid Cancer ◽  
Cancer Risk ◽  
Biological Effects ◽  
The Body ◽  
Male And Female ◽  
Thyroid Dose ◽  
Thyroid Cancer Risk ◽  
Bismuth Shielding ◽  
The Impact

Background: Computed tomography (CT) is vastly applied in X-ray procedures because of its high quality in detecting the anatomical structures of the body. However, it leads to an increase in patient dose, resulting in carcinogenesis. In the head and neck CT, the thyroid is the most important at-risk organ. The aim of this study was to estimate thyroid cancer risk in cervical CT with and without a bismuth shield. Materials and Methods: After obtaining permission from the authors, data related to the thyroid dose of patients undergoing cervical CT in the study by Santos et al (2019) were used, and then thyroid cancer risk was calculated for different ages at exposure in male and female patients using the biological effects of the ionizing radiation (BEIR) VII model. Results: Using bismuth shielding reduced thyroid dose by 37% and 39% in male and female phantoms, respectively. Thyroid cancer estimation demonstrated that the risk was nearly two-fold in females compared to males. Finally, bismuth shielding reduced 40% of cancer risk, and it decreased in both genders by increasing age at exposure. Conclusion: According to our findings, excess relative risk (ERR) up to 0.06% was associated with cervical CT. Although ERR amounts were low, the effect of radiation on thyroid cancer risk should not be neglected. Accordingly, it is suggested that future trials use bismuth shielding to reduce thyroid cancer risk.

scholarly journals Cancerogenesis Risks between 64 and 320 Row Detector CT for Coronary CTA Screening

2014 ◽  
Vol 4 ◽  
pp. 18 ◽  
Author(s):  
Atif N. Khan ◽  
Faisal Khosa ◽  
Boris Nikolic ◽  
Waqas Shuaib ◽  
Pei-Jan Paul Lin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Computed Tomography ◽  
Thyroid Cancer ◽  
Family Member ◽  
Biological Effects ◽  
Significant Coronary Artery Disease ◽  
Relative Reduction ◽  
Ct Scanner ◽  
Old Patients ◽  
Female Breast

Objectives: This study compares cancerogenesis risks posed by the 64 row detector and the 320 row detector computed tomography scanners used during coronary computed tomography angiography (CCTA) following decennial screening guidelines. Material and Methods: Data of the radiation absorbed after CCTA by lung, thyroid, and female breast in patients between 50 and 70 years of age obtained from prior published literature for the 64 row CT scanner were compared with data from our study using 320 row detector CT scanner. Data from the 64 row and the 320 row detector CT scanners was used to determine lifetime attributable risks (LAR) of cancer based on the biological effects of ionizing radiation (BEIR) VII report. Results: The relative reduction of LAR (%) for 50-, 60-, and 70-year-old patients undergoing scanning with the 320 row detector CT scanner was 30% lower for lung, and more than 50% lower for female breast when compared with results from 64 row detector CT scanner. The use of 320 row detector CT would result in a combined cumulative cancer incidence of less than 1/500 for breast in women and less than 1/1000 for lung in men; By comparison, this is much lower than other more common risk factors: 16-fold for lung cancer in persistent smokers, 2-fold for breast cancer with a first degree family member history of breast cancer, and 10-fold for thyroid cancer with a family member with thyroid cancer. Decennial screening would benefit at least 355,000 patients from sudden cardiac death each year, 94% of whom have significant coronary artery disease, with at least one stenosis >75%. LAR for thyroid cancer was negligible for both scanners. Conclusion: Lung and female breast LAR reductions with 320 row detector compared with 64 row detector CT are substantial, and the benefits would outweigh increased cancer risks with decennial screening in the age group of 50-70 years.

Kinetic Aspects of the Interplay of Cancer and the Immune System

2019 ◽  
Vol 14 (02) ◽  
pp. 101-114 ◽  
Author(s):  
Vladimir P. Zhdanov
Keyword(s):  
Stem Cells ◽  
Immune System ◽  
Kinetic Model ◽  
Human Population ◽  
Lifetime Risk ◽  
Risk Of Cancer

The understanding of the interplay between cancer and the immune system is still limited. Herein, I focus on two aspects of this interplay. First, I propose a kinetic model describing the likely role of the immune system in the lifetime risk of cancer at the level of the whole human population. For each tissue, the risk is predicted to be influenced by the heterogeneity of the population and to depend exponentially on time. The expression for the risk does not, however, depend explicitly on the total number of divisions of the corresponding stem cells. For this reason, the correlation with the latter number can only be indirect. Second, using another kinetic framework, I describe how the growth of a few tumors can depend on their interaction via the immune system. The analysis shows that depending on specific details, the tumors of different sizes tend either to reach the same size or remain to be of different sizes.

scholarly journals Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1676
Author(s):  
Giulia Rossi ◽  
Martina Placidi ◽  
Chiara Castellini ◽  
Francesco Rea ◽  
Settimio D'Andrea ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Cellular Damage ◽  
X Rays ◽  
Adolescent Cancer ◽  
Radiation Induced ◽  
Vitro Model ◽  
Underlying Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

scholarly journals The association between XRCC3 rs1799794 polymorphism and cancer risk: a meta-analysis of 34 case–control studies

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Weiqing Liu ◽  
Shumin Ma ◽  
Lei Liang ◽  
Zhiyong Kou ◽  
Hongbin Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Ovarian Cancer ◽  
Thyroid Cancer ◽  
Cancer Risk ◽  
Large Scale ◽  
Meta Analysis ◽  
Cochrane Library ◽  
Cancer Type ◽  
Increased Risk ◽  
Risk Of Cancer

Abstract Background Studies on the XRCC3 rs1799794 polymorphism show that this polymorphism is involved in a variety of cancers, but its specific relationships or effects are not consistent. The purpose of this meta-analysis was to investigate the association between rs1799794 polymorphism and susceptibility to cancer. Methods PubMed, Embase, the Cochrane Library, Web of Science, and Scopus were searched for eligible studies through June 11, 2019. All analyses were performed with Stata 14.0. Subgroup analyses were performed by cancer type, ethnicity, source of control, and detection method. A total of 37 studies with 23,537 cases and 30,649 controls were included in this meta-analysis. Results XRCC3 rs1799794 increased cancer risk in the dominant model and heterozygous model (GG + AG vs. AA: odds ratio [OR] = 1.04, 95% confidence interval [CI] = 1.00–1.08, P = 0.051; AG vs. AA: OR = 1.05, 95% CI = 1.00–1.01, P = 0.015). The existence of rs1799794 increased the risk of breast cancer and thyroid cancer, but reduced the risk of ovarian cancer. In addition, rs1799794 increased the risk of cancer in the Caucasian population. Conclusion This meta-analysis confirms that XRCC3 rs1799794 is related to cancer risk, especially increased risk for breast cancer and thyroid cancer and reduced risk for ovarian cancer. However, well-designed large-scale studies are required to further evaluate the results.

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