Burden of Medical Radiation Exposure in Children with Sickle Cell Disease.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1525-1525 ◽  
Author(s):  
Courtney L. Wendel ◽  
Jon A. Anderson ◽  
Timothy J. Blackburn ◽  
Charles T. Quinn

Abstract Abstract 1525 Poster Board I-548 BACKGROUND Children with sickle cell disease (SCD) present to medical attention repeatedly throughout childhood for medical complications. Chest radiographs are often obtained for fever and respiratory symptoms, and plain radiographs are often ordered because of bone pain. Computed tomography (CT) and nuclear medicine (NM) studies may also be obtained for other complications. Exposure to medical radiation may increase the risk of cancer, especially in children. Growing children are inherently radiosensitive because of their high proportion of dividing cells, and children have more remaining years of life than adults during which cancer can develop. Therefore, it is important to determine the magnitude of medical radiation exposure in children with SCD because they could be so frequently exposed. METHODS We reviewed the medical records for all members of the Dallas Newborn Cohort (Blood 2004;103:4023-7) to determine the number and type of radiographic studies each individual received from 1996 to the present. We recorded the type of radiographic study, body location, clinical indication, date of study, age at the time of study, and the number and types of views when applicable. We also recorded slice thickness and mode for CT scans as well as injection activity, radionuclide, and type of radiopharmaceutical for nuclear medicine studies. To account for different lengths of follow-up, we standardized the number of radiographic studies to yearly rates for each individual to determine the projected number of studies a SCD patient would receive by 18 years of age. RESULTS We studied 938 patients (52.8% male) with a mean follow-up of 9.4 years (median 9.2, range 0.1 – 20.6). 571 had sickle cell anemia (SS), 283 had sickle-hemoglobin C disease (SC), 63 had Sβ+-thalassemia (Sβ+), and 21 had Sβ0-thalassemia (Sβ0). We identified 9,246 radiographic studies, including 8,697 radiographs, 441 CT scans, and 108 NM studies. 711 (76%) patients had at least one radiographic study. Patients with SS or Sβ0 were more likely to have had at least one radiographic study than those with SC or Sβ+ (77% vs. 65%; P<0.0001). The mean number of studies per patient was 9.9 [95% confidence interval (C.I.) 8.9 – 10.9; range 0 – 115], corresponding to a mean rate of 1.5 per year (95% C.I. 1.3 – 1.6; range 0 – 27.3). We project that a patient with SCD will be exposed to the radiation from 26.7 (95% C.I. 24.1 – 29.3; range 0 – 492.1) radiographic studies by 18 years of age. Approximately 5% of patients with SCD will be exposed to 100 or more radiographic studies during childhood. CONCLUSIONS Children with SCD are frequently exposed to medical radiation. Some are exposed to over 100 radiographic studies. Radiographs of the painful part are frequently obtained but are infrequently indicated. Because growing children are more radiosensitive than adults and have more remaining years of life, medical radiation exposure could be clinically significant. We are now calculating the radiation effective doses for this cohort to quantify the risk of malignancy. It is prudent to limit the medical radiation exposure of this high-risk population. Disclosures No relevant conflicts of interest to declare.

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4944-4944
Author(s):  
Maria Acevedo-Mendez ◽  
Anil Rao ◽  
Lewis L. Hsu

Abstract Introduction: Patients with sickle cell disease (SCD) are repeatedly exposed to diagnostic radiation. Radiographs, computed tomography (CT) and nuclear medicine scans are often ordered for suspected complications caused by sickle cell disease that exposes patients with SCD to ionizing or another form of radiation. A few studies of low-dose cumulative radiation exposure (in people without SCD) suggest that 30 to 100 mSv over 30 decades is associated with higher excess risk of leukemia. New epidemiologic data of low quality suggests that individuals with sickle cell disease (SCD) accumulate "driver mutations" for acute myelogenous leukemia (AML) about 20-30 years earlier than the general population, and have higher risk of AML. In a gene therapy protocol with a few dozen patients, 2 cases of AML have occurred in sickle cell disease and none in thalassemia. It has been reported that children with SCD are frequently exposed to ionizing radiation in the form of plain radiographs, fluoroscopy, computed tomography (CT) scans, bone scans, and other tests. Exposure to ionizing radiation during childhood carries a risk of developing cancer that is directly related to the total radiation dose.Epidemiological data has demonstrated an increase both in diagnostic radiation and in actual or predicted resultant cancer diagnosis. Children are particularly vulnerable to radiation-induced cancer because they are still actively growing and thus are at greater risk of acquiring an oncogenic mutation in an actively dividing cell. Hypothesis: Frequent diagnostic imaging for children and adults with SCD can have significant cumulative radiation exposure that could add excess risk of AML. Methods: The study design was a retrospective chart review. The sample was selected to be enriched for the most severely-affected children and adults in the Sickle Cell Center at UI Health, which provides medical care for over 700 patients with SCD. The subgroup on chronic erythrocytapheresis blood transfusionswere selected as a sample of severe of SCD who are more likely to be exposed to repeated diagnostic radiation. Many have had stroke, which often leads to repeated head CT and cerebral angiograms. Others had pulmonary embolism or acute chest syndrome, which can lead to chest CT angiograms. Other SCD complications with high risk of morbidity or morbidity lead to similar likelihood that patients on chronic exchange transfusion therapy would have histories of multiple imaging studies. Medical records were reviewed for the type and number of all radiographic tests, especially CT scans, during the 10-year period 2011-2020. A second observer confirmed a subset of charts. Standard references were used to estimate radiation exposure in mSv for each type of test. The sum of mSv for each individual was a rough estimate of cumulative radiation in 10 years. The IRB approved the protocol. Results: Chart review on 39 patients (ages 16 - 60y) identified 1,030 radiographic tests with a mean of 26.4 tests/patient. Seven patients had &gt; 50 tests, and one patient had &gt; 100 tests over a 10-year period. Thirty-three patients had at least one CT scan. Eighteen patients had at least 3 CT scans. Twenty patients had cumulative radiation exposure &gt; 30 mSv over a 10-year period, 4 patients had &gt; 100 mSv, and one patient had &gt; 200 mSv. Plain radiographs comprised 71% (736) of the studies and relatively low dose radiation exposure. Discussion: This retrospective study estimated that diagnostic radiography exposed 20 of 39 patients with severe SCD to the range of 30 to 200 mSv over 10 years, mostly from numerous CT scans. This range of cumulative radiation exposure has mixed evidence about possible heightened risk of AML and other cancers. The study is limited by the small sample at a single institution and a heavy bias toward patients with stroke and chest complications, but this severely-affected subgroup comprises many of those eligible for transplant and gene therapy in SCD. Cumulative exposure to diagnostic radiation might be one mechanism for the unexplained patterns of AML in SCD after gene therapy that led to a pause in SCD gene therapy studies for a few months in 2021. Further studies are needed. Disclosures Hsu: Global Blood Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Aruvant: Consultancy, Membership on an entity's Board of Directors or advisory committees; Hoffman LaRoche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Forma Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cyclerion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Imara: Research Funding; Eli Lilly: Research Funding; Baxalta / Shire / Takeda: Research Funding.


Children ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 143
Author(s):  
Julie Sommet ◽  
Enora Le Roux ◽  
Bérengère Koehl ◽  
Zinedine Haouari ◽  
Damir Mohamed ◽  
...  

Background: Many pediatric studies describe the association between biological parameters (BP) and severity of sickle cell disease (SCD) using different methods to collect or to analyze BP. This article assesses the methods used for collection and subsequent statistical analysis of BP, and how these impact prognostic results in SCD children cohort studies. Methods: Firstly, we identified the collection and statistical methods used in published SCD cohort studies. Secondly, these methods were applied to our cohort of 375 SCD children, to evaluate the association of BP with cerebral vasculopathy (CV). Results: In 16 cohort studies, BP were collected either once or several times during follow-up. The identified methods in the statistical analysis were: (1) one baseline value per patient (2) last known value; (3) mean of all values; (4) modelling of all values in a two-stage approach. Applying these four different statistical methods to our cohort, the results and interpretation of the association between BP and CV were different depending on the method used. Conclusion: The BP prognostic value depends on the chosen statistical analysis method. Appropriate statistical analyses of prognostic factors in cohort studies should be considered and should enable valuable and reproducible conclusions.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3536-3536
Author(s):  
Cecelia Calhoun ◽  
Regina Abel ◽  
Hai Anh Pham ◽  
Shomari Thompson ◽  
Allison A King

Abstract Background: The transition from the pediatric setting to adult care is a challenge for many adolescents with chronic disease. Patients with sickle cell disease (SCD) represent a unique cohort as the timing of psychosocial development of adolescence often coincides with worsening end organ damage. Previously, we used the Adolescent Autonomy Checklist (AAC) modified to include SCD specific tasks that patients with SCD need to practice in order to transition to adult healthcare and independent living. This study sought to use the AAC to measure the effects of skill based educational handouts on improving self-management and transition readiness in adolescents with SCD. Methods: This was a single center, retrospective study approved by the Washington University Institutional Review Board. Inclusion criteria were patients with SCD, age 13-21 years, and completion of pre and post assessments. As standard care, patients from a pediatric hematology clinic completed the AAC-SCD. The AAC-SCD assesses skill level in twelve domains (Table). The tool includes 100 items, and users check "can do already" or "needs practice" for each item. After review with the coordinator, participants were given skill-based handouts based on up to five noted deficits. Patients completed the AAC-SCD at the subsequent clinic visit. In addition to baseline and follow up AAC-SCD data, medical and demographic data were collected via chart abstraction. All data were entered into SPSS for statistical analysis, including descriptives, paired sample T-tests, and bivariate Pearson's correlations. Results: A total of 61 patients completed baseline and follow up. Of those participants, 49.2% were female. The mean age was 15.4 (+ 2.2) years. The genotypic distribution was as follows: 67.2% HbSS, 19.7% HbSC, 3.3% HbS-beta-thal+ and 9.8% HbS-beta-thal0. The majority of patients received healthcare coverage via Medicaid (52.5%), private insurance (45.6%) and 1.6% had no insurance coverage. Twenty-five patients (42.0 %) had a history of stroke or silent cerebral infarct and 34 (55.7%) were currently taking or were previously prescribed hydroxyurea. Formal academic support (IEP or 504 Plan) was reported for 20 (32.8%) of patients. At baseline, patients needed the most help with skills in the kitchen, housekeeping, personal care and leisure. Statistically significant improvements (p< 0.05) occurred in skills related to laundry, housekeeping, healthcare, sexual development and living arrangements. Modest sized and statistically significant correlation between the receipt of the educational handouts and decreased number of items marked "needs help" occurred in the areas of money management (r=-0.27, p=0.044), vocational skills (r=-0.27, p=0.046;) and laundry (r=0.32, p=0.015). A post hoc analysis by age groups 13-15 (n= 34),16-18 (n=24) and 19-21 (n=3) showed a decreased amount of items marked "needs help" in the areas of sexual development for both 13-15 year olds (r=0.42, p=0.024) and 16-18 year olds (r=0.93, p=0.001) as well. Conclusion: Transition skills improved over time among adolescents with SCD. While we cannot say for certain if gains in knowledge occur with age as development progresses or if a formal transition program can be credited, providing educational materials on transition related skills within a clinic setting was associated with significant improvements in three of the domains. Our preliminary data offers insight into what skill deficits may be most amenable to educational interventions based on age group. As is the case with medical management, the development of a multimodal intervention is needed to prepare adolescents with SCD to transition to adult care and independent living. Clinic based education is a simple intervention that could be one component of future approaches to transition. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 68-68 ◽  
Author(s):  
Janet L. Kwiatkowski ◽  
Julie Kanter ◽  
Heather J. Fullerton ◽  
Jenifer Voeks ◽  
Ellen Debenham ◽  
...  

Abstract Background: The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) established routine transcranial Doppler ultrasound (TCD) screening with indefinite chronic red cell transfusions (CRCT) for children with abnormal TCD as standard of care. To identify children at high-risk of stroke, annual TCD screening is recommended from ages 2 to 16 years, with more frequent monitoring if the result is not normal. A reduction in stroke incidence in children with SCD has been reported in several clinical series and analyses utilizing large hospital databases when comparing rates before and after the publication of the STOP study in 1998. We sought to determine the rate of first ischemic stroke in a multicenter cohort of children who had previously participated in the STOP and/or STOP 2 trials and to determine whether these strokes were screening or treatment failures. Subjects and Methods: Between 1995 and 2005, STOP and STOP 2 (STOP/2) were conducted at 26 sites in the US and Canada. These studies included 3,835 children, ages 2 to 16 y with SCD type SS or S-beta-0-thalassemia. Participation in STOP/2 ranged from a single screening TCD to randomization. STOP 2 also had an observational arm for children on CRCT for abnormal TCD whose TCD had not reverted to normal. The Post-STOP study was designed to follow-up the outcomes of children who participated in one or both trials. 19 of the 26 original study sites participated in Post-STOP, contributing a total of 3,539 (92%) of the STOP/2 subjects. After exit from STOP/2, these children received TCD screening and treatment according to local practices. Data abstractors visited each clinical site and obtained retrospective data from STOP/2 study exit to 2012-2014 (depending on site) including follow-up TCD and brain imaging results, clinical information, and laboratory results. Two vascular neurologists, blinded to STOP/2 status and prior TCD and neuroimaging results, reviewed source records to confirm all ischemic strokes, defined as a symptomatic cerebral infarction; discordant opinions were resolved through discussion. For the first Post-STOP ischemic stroke, prior TCD result and treatment history subsequently were analyzed. Results: Of the 3,539 subjects, follow-up data were available for 2,850 (81%). Twelve children who had a stroke during STOP or STOP2 were excluded from these analyses resulting in data on 2,838 subjects. The mean age at the start of Post-STOP was 10.5 y and mean duration of follow-up after exiting STOP/2 was 9.1 y. A total of 69 first ischemic strokes occurred in the Post-STOP observation period (incidence 0.27 per 100 pt years). The mean age at time of stroke was 14.4±6.2 (median 13.8, range 3.5-28.9) y. Twenty-five of the 69 patients (36%) had documented abnormal TCD (STOP/2 or Post-STOP) prior to the stroke; 15 (60%) were receiving CRCT and 9 (36%) were not (treatment data not available for 1 subject). Among the 44 subjects without documented abnormal TCD, 29 (66%) had not had TCD re-screen in the Post-STOP period prior to the event; 7 of these 29 (24%) were 16 y or older at the start of Post-STOP, which is beyond the recommended screening age. Four of the 44 (9%) patients had inadequate TCD in Post-STOP (1 to 10.7 y prior to event). Six (14%) had normal TCD more than a year before the event (1.2 - 4 y); all but one of these children were younger than 16 y at the time of that TCD. Only 5 (11%) had a documented normal TCD less than 1 year prior to the event. Conclusions: In the Post-STOP era, the rate of first ischemic stroke was substantially lower than that reported in the Cooperative Study of Sickle Cell Disease, prior to implementation of TCD screening. Many (39%) of the Post-STOP ischemic strokes were associated with a failure to re-screen according to current guidelines, while only 11% occurred in children who had had recent low-risk TCD. Among those known to be at high risk prior to stroke, treatment refusal or inadequate treatment may have contributed. While TCD screening and treatment are effective at reducing ischemic stroke in clinical practice, significant gaps in screening and treatment, even at sites experienced in the STOP protocol, remain to be addressed. Closing these gaps should provide yet further reduction of ischemic stroke in SCD. Disclosures No relevant conflicts of interest to declare.


PEDIATRICS ◽  
1989 ◽  
Vol 83 (5) ◽  
pp. 913-914
Author(s):  
Neil A. Holtzman

Ten years ago, the initial report of the Committee on Genetics of the American Academy of Pediatrics was published, drawing heavily on the landmark report published 2 years earlier by the National Academy of Sciences. That report stated that new mass screening tests should not be implemented without pilot studies or facilities for follow-up. I would like to deal with the efficacy of screening as determined by pilot studies, the effectiveness of routine screening, and the importance of follow-up. The Cooperative Study of Sickle Cell Disease was essentially the first phase of a large pilot program that systematically demonstrated that sepsis, meningitis, and acute splenic sequestration occurred in young infants with sickle cell disease. Previous reports suggested, and the cooperative study corroborated, that without prior diagnosis many of these infants would die. The randomized trial of oral penicillin prophylaxis was the second phase of the pilot program, demonstrating that early treatment significantly reduced mortality. Thus, the results of this pilot program, conducted with support of the National Institutes of Health, documented that newborn screening for sickle cell disease satisfied a major criterion for screening: An intervention capable of reducing mortality would be efficacious if applied before the usual age of clinical diagnosis. The pilot program was conducted under ideal conditions. The findings are not enough to conclude that screening for sickle cell disease and other hemoglobinopathies will always be effective when performed routinely.


2019 ◽  
Vol 6 ◽  
pp. 2333794X1984702 ◽  
Author(s):  
Michael D. Cabana ◽  
Julie Kanter ◽  
Anne M. Marsh ◽  
Marsha J. Treadwell ◽  
Michael Rowland ◽  
...  

National guidelines recommend that providers counsel all patients with sickle cell anemia about hydroxyurea (HU) therapy and screen children with sickle cell anemia annually for the risk of stroke with transcranial Doppler (TCD). We surveyed a national convenience sample of sickle cell disease clinicians to assess factors associated with low adherence. Adherence was 46% for TCD screening. Low adherence was associated with a lack of outcome expectancy (eg, a belief that there would be poor patient follow-up to TCD testing; P < .05). Adherence was 72% for HU counseling. Practice barriers (eg, lack of support staff or time) and a lack of agreement with HU recommendations were associated with low adherence ( P < .05). This study demonstrates that different types of strategies are needed to improve TCD screening (to address follow-up and access to testing) versus HU counseling (to address physician agreement and practice barriers).


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