Differences in radiation-induced heart dysfunction in male versus female rats.

PURPOSE: Radiation therapy remains part of the standard of care for breast, lung, and esophageal cancers. While radiotherapy improves local control and survival, radiation-induced heart dysfunction is a common side effect of thoracic radiotherapy. Cardiovascular dysfunction can also result from non-therapeutic total body radiation exposures. Numerous studies have evaluated the relationship between radiation dose to the heart and cardiotoxicity, but relatively little is known about whether there are differences based on biological sex in radiation-induced heart dysfunction (RIHD). MATERIALS AND METHODS: We evaluated whether male and female inbred Dahl SS rats display differences in RIHD following delivery of 24 Gy in a single fraction to the whole heart using a 1.5 cm beam size (collimater). We also compared the 2.0 cm vs. 1.5 cm collimator in males. Pleural and pericardial effusions and normalized heart weights were measured, and echocardiograms were performed. RESULTS: Female SS rats displayed more severe RIHD relative to age-matched SS male rats. Normalized heart weight was significantly increased in females, but not in males. A total of 94% (15/16) of males and 55% (6/11) of females survived 5 months after completion of radiotherapy (p < .01). Among surviving rats, 100% of females and 14% of males developed moderate-to-severe pericardial effusions at 5 months. Females demonstrated increased pleural effusions, with the mean normalized pleural fluid volume for females and males being 56.6 mL/kg ± 12.1 and 10.96 mL/kg ± 6.4 in males (p = .001), respectively. Echocardiogram findings showed evidence of heart failure, which was more pronounced in females. Because age-matched female rats have smaller lungs, a higher percentage of the total lung was treated with radiation in females than males using the same beam size. After using a larger 2 cm beam in males which results in higher lung exposure, there was not a significant difference between males and females in terms of the development of moderate-to-severe pericardial effusions or pleural effusions. Treatment of males with a 2 cm beam resulted in comparable increases in LV mass and reductions in stroke volume to female rats treated with a 1.5 cm beam. CONCLUSION: Together, these results illustrate that there are differences in radiation-induced cardiotoxicity between male and female SS rats and add to the data that lung radiation doses, in addition to other factors, may play an important role in cardiac dysfunction following heart radiation exposure. These factors may be important to factor into future mitigation studies of radiation-induced cardiotoxicity.

Clinical Practices in Central Venous Catheter Mechanical Adverse Events.

Background: Over 5 million central venous catheters (CVCs) are placed annually. Pneumothorax and catheter malpositioning are common adverse events (AE) that requires attention. This study aims to evaluate local practices of mechanical complication frequency, type, and subsequent intervention(s) related to mechanical AE with an emphasis on catheter malpositioning. Methods: This is a retrospective review of CVC placements in a tertiary hospital setting from 1/2013 to 12/2013. Pneumothorax and CVC positioning were evaluated on post-insertion chest x-ray (CXR). Malposition was defined as unintended placement of the catheter in a vessel other than the intended superior vena cava on CXR. Catheter reposition was defined as radiographic evidence of a new catheter with removal of the old catheter less than 24hrs after initial placement. Data points analyzed included pneumothorax and thoracostomy rate, CVC malposition frequency, catheter reposition rate, catheter duration, and incidence of complications such as catheter associated venous thrombosis. Result: Among 2045 eligible CVC insertions, pneumothoraces occurred in 14 (0.7%; 95%CI 0.38, 1.17) and malpositions were identified in 275 (13.4%; 95% CI 12.3, 15.3). The proportion of pneumothoraces that required tube thoracostomy was 57%. The proportion of CVCs with malposition that were removed or replaced within 24h was 32.7%. "Malpositioned" catheters that were left in place by the clinical team (n = 185) had an average catheter duration of 8.2 days (95% CI 7.2, 9.3) versus 7.2 days (95% CI 6.17, 8.23) for catheters that were replaced after initial malposition (p = 0.14, t test). The incidence of venous thrombosis in repositioned "malpositioned" catheters was 7.8% versus 4.9% for "malpositioned" catheters that were left in place. Conclusions: Clinically significant catheter malposition and pneumothorax after CVC insertion are low. In this study, replaced and non-replaced "malpositioned" catheters had similar catheter duration and rates of complications, challenging the current dogma of CVC malposition practice.

Meta-Analysis of Point-of-Care Lung Ultrasonography Versus Chest Radiography in Adults With Symptoms of Acute Decompensated Heart Failure.

Acute decompensated heart failure (ADHF) is a primary cause of older adults presenting to the emergency department with acute dyspnea. Point-of-care lung ultrasound (LUS) has shown comparable or superior diagnostic accuracy in comparison with a chest x-ray (CXR) in patients presenting with symptoms of ADHF. The systematic review and meta-analysis aimed to elucidate the sensitivity and specificity of LUS in comparison with CXR for diagnosing ADHF and summarize the rapidly growing body of evidence in this domain. A total of 5 databases were searched through February 18, 2021, to identify observational studies that reported on the use of LUS compared with CXR in diagnosing ADHF in patients presenting with shortness of breath. Meta-analysis was conducted on the sensitivities and specificities of each diagnostic method. A total of 8 studies reporting on 2,787 patients were included in this meta-analysis. For patients presenting with signs and symptoms of ADHF, LUS was found to be more sensitive than CXR (91.8% vs 76.5%) and more specific than CXR (92.3% vs 87.0%) for the detection of cardiogenic pulmonary edema. In conclusion, LUS is more sensitive and specific than CXR in detecting pulmonary edema. This highlights the importance of sonographic B-lines, along with the accurate interpretation of clinical data, in the diagnosis of ADHF. In addition to its convenience, reduced costs, and reduced radiation exposure, LUS should be considered an effective alternative to CXR for evaluating patients with dyspnea in the setting of ADHF.

Should pulmonary radiographs be taken routinely following paediatric tracheostomy?

AIM: As the rates of complications related to tracheostomy procedures have fallen in recent years, the routine taking of pulmonary radiographs following tracheostomy has become a matter of debate. The aim of this study was to compare the incidence of complications developing in 120 children who had pulmonary radiographs taken following surgical tracheostomy and to thereby evaluate the necessity of routine pulmonary radiographs after tracheostomy. METHODS: The data were retrospectively reviewed of 120 children who had pulmonary radiographs taken following surgical tracheostomy between January 2012 and January 2018. The pulmonary radiographs taken before and immediately after tracheostomy were evaluated independently by two paediatric radiology specialists and the results were recorded. RESULTS: The incidence of complications after tracheostomy was determined as 23.3%, and no pneumothorax was determined in any patient. An increase was not seen in the complication incidence in those who had undergone emergency tracheostomy and patients aged < 2 years, which are accepted as high-risk groups. In the evaluation of the pre- and post-tracheostomy radiographs, new findings were determined on the post-tracheostomy radiograph that had not been there previously in eight patients (6.6%). These findings were newly formed infiltration in seven patients (5.8%), and malposition of the tracheostomy tube in one patient (0.8%). No pathology requiring intervention was determined on the radiographs of any patient. CONCLUSION: The results of this study support the view that it is not necessary to take pulmonary radiographs routinely following tracheostomy in the paediatric age group, including those at higher risk.

What is the role of chest X-ray imaging in the acute management of children with sickle cell disease?

Children with sickle cell disease (SCD) frequently present to hospital acutely unwell and are often exposed to diagnostic chest X-rays (CXRs). Little evidence exists to determine when CXRs are clinically useful. Using electronic hospital records, we audited CXR use in children aged 0-18 who presented to hospital over the past 10 years in both an inpatient and emergency department setting. From a total of 915 first CXRs, only 28·2% of CXRs (n = 258) had clinically significant findings that altered management or final diagnosis. Of these abnormalities, consolidation represented 52·3%, effusion 8·9%, cardiomegaly 8·4% and sickle cell-related bone changes 6·3%. Indications for CXR of respiratory distress (OR = 3·74, 95% CI 2·28-6·13), hypoxia (OR = 1·86, 95% CI 1·50-2·31) and cough (OR = 1·64, 95% CI 1·33-2·02), were more likely to have significant CXR findings. Patients who had higher peak fever (38·4°C vs. 37·4°C, P = 0·001), higher peak CRP (156·4 vs. 46·1, P < 0·001) and higher WCC (20·2 vs. 13·6, P < 0·001) were more likely to have clinically significant abnormalities on CXR. We found a decision tool using either hypoxia, cough, respiratory distress, T > 38°C, CRP > 50 or WCC > 15 × 109 /l as indications for CXR, to have a sensitivity of 88% (with 95% CI 0·78-0·95) and specificity of 46% (95% CI 0·43-0·50) for clinically significant findings.

Diagnostic yield, safety, and advantages of ultra-low dose chest CT compared to chest radiography in early stage suspected SARS-CoV-2 pneumonia: A retrospective observational study.

ABSTRACT: To determine the role of ultra-low dose chest computed tomography (uld CT) compared to chest radiographs in patients with laboratory-confirmed early stage SARS-CoV-2 pneumonia.Chest radiographs and uld CT of 12 consecutive suspected SARS-CoV-2 patients performed up to 48 hours from hospital admission were reviewed by 2 radiologists. Dosimetry and descriptive statistics of both modalities were analyzed.On uld CT, parenchymal abnormalities compatible with SARS-CoV-2 pneumonia were detected in 10/12 (83%) patients whereas on chest X-ray in, respectively, 8/12 (66%) and 5/12 (41%) patients for reader 1 and 2. The average increment of diagnostic performance of uld CT compared to chest X-ray was 29%. The average effective dose was, respectively, of 0.219 and 0.073 mSv.Uld CT detects substantially more lung injuries in symptomatic patients with suspected early stage SARS-CoV-2 pneumonia compared to chest radiographs, with a significantly better inter-reader agreement, at the cost of a slightly higher equivalent radiation dose.

Unintentional exposure and incidental findings during conventional chest radiography in the pediatric intensive care unit.

ABSTRACT: Radiation overexposure is common in chest X-ray (CXRs) of pediatric patients. However, overexposure may reveal incidental findings that can help to guide patient management or warrant quality improvement.To assess the prevalence of overexposure in CXRs in pediatric intensive care unit (PICU); and identify the incidental findings within overexposed areas, we conducted a retrospective cohort study of children who were admitted to PICU. Two independent evaluators reviewed patient's charts and digital CXRs according to the American College of Radiology standards; to evaluate overexposure of the anatomical parameters and incidental findings.A total of 400 CXRs of 85 patients were reviewed. The mean number of CXRs per patient was 4.7. Almost all (99.75%) CXRs met the criteria for overexposure, with the most common being upper abdomen (99.2%), upper limbs (97%) and neck (95.7%). In addition, 43% of these X-rays were cropped by the radiology technician to appear within the requested perimeter. There was a significant association between field cropping and overexposure (t-test: t = 9.8, P < .001). Incidental findings were seen in 41.5% of the radiographs; with the most common being gaseous abdominal distension (73.1%), low-positioned nasogastric tube (24.6%), and constipation (10.3%).Anatomical overexposure in routine CXRs remains high and raises a concern in PICU practice. Appropriate collimation of the X-ray beam, rather than electronically cropping the image, is highly recommended to minimize hiding incidental findings in the cropped-out areas. Redefining the anatomic boundaries of CXR in critically ill infants and children may need further studies and consideration. Quality improvement initiatives to minimize radiation overexposure in PICU are recommended, especially in younger children and those with more severe illness upon PICU admission.

Is a chest radiograph indicated after chest tube removal in trauma patients? A systematic review.

PURPOSE: The aim of this systematic review was to assess the necessity of routine chest radiographs after chest tube removal in ventilated and nonventilated trauma patients. METHODS: A systematic literature search was conducted in MEDLINE, Embase, CENTRAL, and CINAHL on May 15, 2020. Quality assessment was performed using the Methodological Index for Nonrandomized Studies criteria. Primary outcome measures were abnormalities on postremoval chest radiograph (e.g., recurrence of a pneumothorax, hemothorax, pleural effusion) and reintervention after chest tube removal. Secondary outcome measures were emergence of new clinical symptoms or vital signs after chest tube removal. RESULTS: Fourteen studies were included, consisting of seven studies on nonventilated patients and seven studies on combined cohorts of ventilated and nonventilated patients, all together containing 1,855 patients. Nonventilated patients had abnormalities on postremoval chest radiograph in 10% (range across studies, 0-38%) of all chest tubes and 24% (range, 0-78%) of those underwent reintervention. In the studies that reported on clinical symptoms after chest tube removal, all patients who underwent reintervention also had symptoms of recurrent pathology. Combined cohorts of ventilated and nonventilated patients had abnormalities on postremoval chest radiograph in 20% (range, 6-49%) of all chest tubes and 45% (range, 8-63%) of those underwent reintervention. CONCLUSION: In nonventilated patients, one in ten developed recurrent pathology after chest tube removal and almost a quarter of them underwent reintervention. In two studies that reported on clinical symptoms, all reinterventions were performed in patients with symptoms of recurrent pathology. In these two studies, omission of routine postremoval chest radiograph seemed safe. However, current literature remains insufficient to draw definitive conclusions on this matter, and future studies are needed. LEVEL OF EVIDENCE: Systematic review study, level IV.

(F)utility of "routine" postprocedural chest radiograph after hemodialysis catheter (central venous catheter) insertion.

A routine postprocedural chest radiograph had been a safe, checklist-based final step of the procedure, since the start of central venous catheter insertion for hemodialysis to check the position of the catheter tip and to rule out complications. However, the chest radiograph is a suboptimal method to rule out complications like pneumothorax and is not a reliable test to confirm its position. Although it is relatively inexpensive, it is labor-intensive and exposes patient to unnecessary radiation exposure, cost, and often results in delayed use of the catheter. Various studies question the value of a routine chest radiograph as a screening test to rule out the mechanical complications of catheter insertion. We, in this brief viewpoint, present evidence to support the futility of a routine postprocedural chest radiograph in majority of asymptomatic patients and support Choosing Wisely Initiative to avoid low-value studies. However, it should be considered under specific indications, as discussed.

Evaluation of Radiation Doses in Pediatric Patients Undergoing Conventional Chest X-ray Examination.

ABSTRACT: This work deals with the evaluation of radiation doses from chest x rays for 240 male and female pediatric patients selected randomly from four Palestinian hospitals. The patient population was divided into five age groups: Newborn, 1, 5, 10, and 15 y old. Doses were theoretically calculated by using Monte Carlo based codes: CALDOSE-X5 and PCXMC-2.0. Patients' data and type of radiographic systems used as well as exposure factors were provided by the administrations of the selected hospitals. Absorbed organ doses from AP and PA projections were evaluated for 76 pediatric patients selected from one hospital in East Jerusalem. The highest mean organ dose for these patients was 0.085 mGy to the breast in AP projection. Effective doses were estimated for the five age groups for all patients. The highest average effective dose was found for patients in the age group of 10 y and was about 0.13 mSv, while the lowest average effective dose was found for the 5-y age group, about 0.06 mSv. The mean effective dose for all investigated patients in the five age categories was about 0.08 mSv. Variations in effective doses for the same age group and x-ray examination among involved hospitals are remarkable.

Clinical Benefits, Harms, and Cost-Effectiveness of Breast Cancer Screening for Survivors of Childhood Cancer Treated With Chest Radiation : A Comparative Modeling Study.

BACKGROUND: Surveillance with annual mammography and breast magnetic resonance imaging (MRI) is recommended for female survivors of childhood cancer treated with chest radiation, yet benefits, harms, and costs are uncertain. OBJECTIVE: To compare the benefits, harms, and cost-effectiveness of breast cancer screening strategies in childhood cancer survivors. DESIGN: Collaborative simulation modeling using 2 Cancer Intervention and Surveillance Modeling Network breast cancer models. DATA SOURCES: Childhood Cancer Survivor Study and published data. TARGET POPULATION: Women aged 20 years with a history of chest radiotherapy. TIME HORIZON: Lifetime. PERSPECTIVE: Payer. INTERVENTION: Annual MRI with or without mammography, starting at age 25, 30, or 35 years. OUTCOME MEASURES: Breast cancer deaths averted, false-positive screening results, benign biopsy results, and incremental cost-effectiveness ratios (ICERs). RESULTS OF BASE-CASE ANALYSIS: Lifetime breast cancer mortality risk without screening was 10% to 11% across models. Compared with no screening, starting at age 25 years, annual mammography with MRI averted the most deaths (56% to 71%) and annual MRI (without mammography) averted 56% to 62%. Both strategies had the most screening tests, false-positive screening results, and benign biopsy results. For an ICER threshold of less than $100 000 per quality-adjusted life-year gained, screening beginning at age 30 years was preferred. RESULTS OF SENSITIVITY ANALYSIS: Assuming lower screening performance, the benefit of adding mammography to MRI increased in both models, although the conclusions about preferred starting age remained unchanged. LIMITATION: Elevated breast cancer risk was based on survivors diagnosed with childhood cancer between 1970 and 1986. CONCLUSION: Early initiation (at ages 25 to 30 years) of annual breast cancer screening with MRI, with or without mammography, might reduce breast cancer mortality by half or more in survivors of childhood cancer. PRIMARY FUNDING SOURCE: American Cancer Society and National Institutes of Health.

[Computed tomography in children with cystic fibrosis: The role of an expiratory protocol]. / Scanner thoracique chez l'enfant atteint de mucoviscidose : intérêt d'un protocole en expiration séquentielle pour réduire la dose d'irradiation.

INTRODUCTION: Chest computed tomography (CT) is essential to monitor lung disease in children with cystic fibrosis, but it involves recurrent exposure to ionizing radiation. The aim of this study was to compare the current complete CT protocol (volumetric end-inspiratory plus sequential expiratory acquisition) to a sequential expiratory acquisition protocol alone in terms of image analysis and ionizing radiation dose. METHODS: Seventy-eight CT scans from 57 children aged 5 to 18 years old were scored on the complete protocol images and on the expiratory sequential images only. Each CT protocol was scored independently, using the Brody scoring system, by two paediatric radiologists. RESULTS: Correlations between the Brody global scores of the two different CT protocols were very good (r=0.90 for both observers), for the bronchiectasis score (r=0.72 and 0.86), mucus plugging score (r=0.87 and 0.83), and expiratory trapped air (r=0.96 and 0.92). Total ionizing radiation dose was reduced, with the measured dose length product (DLP) reduced from 103.31mGy.cm (complete protocol) to 3.06mGy.cm (expiratory protocol) (P<0.001). CONCLUSION: An expiratory chest CT protocol was accurate in diagnosing early signs of CF disease and permitted significant reduction of radiation dose. This protocol would allow spacing out of complete CT scanning with its higher radiation dose and should be considered for the monitoring of lung disease severity in children with CF.

Image quality and radiation dose reduction in chest CT in pulmonary infection.

PURPOSE: To evaluate the effect of dose reduction with iterative reconstruction (IR) on image quality of chest CT scan comparing two protocols. MATERIALS AND METHODS: Fifty-nine patients were enrolled. The two CT protocols were applied using Iterative Reconstruction (ASIR™) 40% but different noise indexes, recording dose-length product (DLP) and volume computed tomography dose index (CTDIvol). The subjective IQ was rated based on the distinction of anatomic details using a 4-point Likert scale based on the European Guidelines on Quality Criteria for CT. For each patient, two single CTs, at enrollment (group 1) and at follow-up after lowering the dose (group 2), were evaluated by two radiologists evaluating, for each examination, five different lung regions (central zone-CZ; peripheral zone-PZ; sub-pleural region-SPR; centrilobular region-CLR; and apical zone-AZ). An inter-observer agreement was expressed by weighted Cohen's kappa statistics (k) and intra-individual differences of subjective image analysis through visual grading characteristic (VGC) analysis. RESULTS: An average 50.4% reduction in CTDIvol and 51.5% reduction in DLP delivered were observed using the dose-reduced protocol. An agreement between observers evaluating group 1 CTs was perfect (100%) and moderate to good in group 2 examinations (k-Cohen ranging from 0.56 for PZ and AZ to 0.70 for SPR). In the VGC analysis, image quality ratings were significantly better for group 1 than group 2 scans for all regions (AUCVGC ranging from 0.56 for CZ to 0.62). However, disagreement was limited to a score 4 (excellent)-to-score 3 (good) IQ transition; apart from a single case in PZ, both the observers scored the IQ at follow-up as 2 (sufficient) starting from a score 4 (excellent). CONCLUSION: Dose reduction achieved in the follow-up CT scans, although a lower IQ still allows a good diagnostic confidence.

Cumulative radiation exposure during current scoliosis management.

INTRODUCTION: Patients undergoing scoliosis management are exposed to repeated radiological imaging. Previous studies have shown an increase in incidence of cancer among these patients. The primary aim of this study was to evaluate the radiographic examinations and cumulative radiation dose to which scoliotic patients are exposed. A secondary aim was to compare in-house algorithms of scoliosis management and radiographic follow-up to international spine centres and current consensus literature. MATERIALS AND METHODS: A single-centre retrospective review evaluating type and frequency of radiographic imaging and total cumulative radiation exposure to patients treated for scoliosis. Inclusions: patients followed for idiopathic scoliosis in the years 2013-2016. A survey asking for information on management and radiological follow-up algorithms was sent to a number of international spine centres for comparison with the in-house algorithm. RESULTS: Patients who underwent surgery received an approximately ten-fold higher median cumulative radiation dose than those treated conservatively. A variety of radiological follow-up algorithms among eight spine centres was observed. CONCLUSIONS: Cumulative radiation dose during scoliosis treatment varies substantially depending on radiographic follow-up protocol, intraoperative and ancillary imaging. By using low-dose X-ray systems in combination with a low-dose protocol for intraoperative navigation, it is possible to keep exposure to patients at a minimum while still providing optimal care. FUNDING: none. TRIAL REGISTRATION: not relevant.

EFFECTIVE DOSE AND RISK ESTIMATES IN ADULT PATIENTS FROM FOUR RADIOLOGICAL PROCEDURES EXTRAPOLATED OVER TWO POPULATIONS AT SOME SELECTED CENTERS IN LAGOS STATE, NIGERIA.

In this study, risk of exposure to adult patients in some common radiological procedures was estimated at selected diagnostic centers in Lagos State, Nigeria using estimated average effective doses. The results showed that pelvis lateral (LAT) examination with the lowest estimated mean effective dose level (2.61) recorded the highest probability of cancer incidence and mortality occurrences, while lumbar anteroposterior (AP) had the lowest (3.61). A high sum total of probability of fatal cancers and the total weighted probability of non-fatal cancer in a single exposure to low-dose ionizing radiation were recorded in pelvic procedure among others. Also, a high-percentage mortality increase of solid cancers was recorded in chest PA examination (53.7%), while the lowest was in lumbar spine radiography (with lumbar AP = 0.14%, lumbar LAT = 0.15%). The data obtained suggested the possibility of having higher percentage mortality and cancer-related incidence in the chest.

Cost-Effectiveness of a Guided Peripherally Inserted Central Catheter Placement System: A Single-Center Cohort Study.

PURPOSE: To assess the cost-effectiveness of peripherally inserted central catheter (PICC) placements using an ultrasound and electrocardiogram-guided system versus external measurements and confirmatory chest X-rays (CXRs). MATERIALS AND METHODS: Sixty-eight guided PICC placements were performed in 63 outpatients (mean age, 43 ± 13 years; 50% male) and compared to 68 propensity score-matched PICC placements (mean age, 44 ± 13 years; 56% male) performed using external measurements by the same operators. Post-placement CXRs were used to confirm final catheter tip positioning. Cohorts were compared in terms of repositioning rates, desired tip positioning rates (in the lower third of the superior vena cava or at the cavoatrial junction), and estimated cost per PICC positioned as desired using manufacturer quotes, Medicare reimbursement rates, and hourly wages for staff time. Agreement between tip positioning according to the guided system versus CXR was also assessed. RESULTS: Guided PICC placements required less repositioning (1.5% vs 10.3%, P = .03) and resulted in more catheters positioned as desired (86.8% vs 67.6%, P = .01) than the external measurement approach. The cost per PICC positioned as desired was lower for guided placements ($318.54 vs $381.44), suggesting that the guided system was cost-effective in this clinical setting. Guided system-CXR agreement for tip position was poor (κ=0.25, P = .002) due to tips being slightly farther from the cavoatrial junction on CXR than indicated by the guided system. CONCLUSIONS: The guided PICC placement system was cost-effective in outpatients treated by a single division of interventional radiology at an academic institution.

Low-dose paediatric cardiac and thoracic computed tomography with prospective triggering: Is it possible at any heart rate?

OBJECTIVE: To demonstrate that the use of step-and-shoot (SAS) mode in paediatric cardiac CT angiography (CCTA) is possible at heart rates (HR) greater than 65 bpm, allowing low-dose acquisition with single-source 64-slices CT. METHODS: We retrospectively included 125 paediatric patients (0-6 years). CCTA was performed with SAS at diastolic phase in 31 patients (group D, HR < 65 bpm), at systolic phase in 45 patients (group S, HR ≥ 65 bpm) and with non-gated mode in 49 patients (group NG). Effective dose (ED) and image quality using a 3-grade scoring scale (1, excellent; 2, moderate; 3, insufficient) of group S were compared with group D for coronary examinations and group NG for entire thorax vascular anatomy. RESULTS: For coronary indications, median ED was 0.6 mSv in group D versus 0.9 mSv in group S (p < 0.01). For whole thorax indications, median ED was 2.7 mSv in group NG versus 1.1 mSv in group S (p < 0.001). The mean image quality score was (1.4 ±â€¯0.6) points in group D, (1.4 ±â€¯0.7) in group S for coronary indications (p = 0.9), (1.3 ±â€¯0.6) in group S for whole thorax indications and (2.0 ±â€¯0.0) in group NG (p < 0.001). CONCLUSION: SAS mode is feasible in children with HR greater than 65 bpm allowing low-dose CCTA. It provided comparable image quality in systole, compared to diastole. SAS at the systolic phase provided better image quality with less radiation dose compared to non-gated scans for whole thorax examinations.

Clinical and histological features of second breast cancers following radiotherapy for childhood and young adult malignancy.

OBJECTIVE: The purpose of this study was to determine the characteristics of early second breast cancer (SBC) among survivors of childhood and young adult malignancy treated with irradiation. METHODS: We conducted a multicenter retrospective study of women who presented with breast cancer aged 50 years or younger in nine French centers. RESULTS: 121 patients and 141 SBC were analyzed (invasive = 130; non-invasive = 11). The mean age at first cancer diagnosis was 15 years and at initial SBC diagnosis was 38 years. Bilateral disease before the age of 51 years was diagnosed in 16% of the females. The majority of SBC were invasive carcinomas (92%). Among the invasive carcinomas, 39% had a histoprognostic score of III, 3.1% overexpressed HER2 and 29% were triple negative. The proportion of triple negative phenotype SBC was higher in patients older at first cancer diagnosis [RR = 1.2, 95% CI (1.1-1.3)]. 94% of triple negative SBCs developed in breast tissue which had received >20 Gy. CONCLUSION: We found a high proportion of aggressive SBC following thoracic radiotherapy in childhood or early adulthood. Advances in knowledge: SBC screening is recommended by scientific societies for these child/young-adulthood cancer survivors in the same way as the one for high risk women because of constitutional mutations. Our results support these recommendations, not only because of a similar cumulative risk, but also because of the aggressive histological characteristics.

Risk of early-onset breast cancer among women exposed to thoracic computed tomography in pregnancy or early postpartum.

Essentials Tests for pulmonary embolism expose women to low-dose radiation. 5859 pregnancies had a thoracic computed tomography (T-CT) vs. 1.3 million who did not. The adjusted hazard ratio for breast cancer was 1.17 (95% confidence interval 0.80-1.70). The long-term risk of breast cancer among women who had a T-CT remains unknown. SUMMARY: Background The risk of breast cancer may be higher with direct exposure to ionizing radiation from thoracic computed tomography (CT) during pregnancy or the postpartum. We evaluated the short-term risk of maternal breast cancer after exposure to thoracic CT during these periods. Methods We completed a retrospective population-based cohort study of all deliveries between 1995 and 2014 using universal healthcare databases in the province of Ontario, Canada. The main exposure was thoracic CT in pregnancy or ≤ 42 days postpartum. The passive exposure was ventilation-perfusion scintigraphy (VQ) scan in pregnancy or ≤ 42 days postpartum. Each was compared to pregnancies unexposed to thoracic CT or VQ scan. The primary study outcome was newly diagnosed breast cancer starting 366 days post-index delivery date. Results A total of 5859 pregnancies were exposed to thoracic CT, 4075 to VQ scan and 1 292 059 to neither. Starting from 1 year after the index delivery, the median duration of follow-up was 5.9, 7.3 and 11.1 years, respectively. A total of 10 129 women were diagnosed with breast cancer, of whom 9039 (89.2%) were aged ≤ 50 years. There were 27 new cases of breast cancer (7.1 per 10 000 person-years) following thoracic CT vs. 10 080 (7.0 per 10 000 person-years) among the unexposed, an adjusted hazard ratio (HR) of 1.17 (95% confidence interval [CI], 0.80-1.70). Following VQ scan exposure, the incidence rate of breast cancer was 7.0 per 10 000 person-years, an adjusted HR of 1.23 (95% CI 0.81-1.87), compared with the unexposed cohort. Conclusion Exposure to thoracic CT during pregnancy or the postpartum was not associated with an increased short-term risk of maternal breast cancer. The long-term risk should be studied.

ESTIMATION OF FEMALE RADIATION DOSES AND BREAST CANCER RISK FROM CHEST CT EXAMINATIONS.

Breast organ doses, effective doses and lifetime attributable risk (LAR) of breast cancer from chest CT scans are presented for 200 female patients surveyed from 10 hospitals in the West Bank and Gaza Strip, Palestine. Patient data were collected and organized in a database from May to November 2016. Data include age (15-80 years), weight, height, and calculated body mass index. Exposure data were also recorded for every examination. Exposure data includes milliampere-second (mAs), X-ray tube kilovoltage (kVp), computed tomography dose index, dose length product, manufacturer, name and type of operated CT scanner. Organ and effective doses were evaluated using a web-based commercially available Monte Carlo software: VirtualDose™CT, a product of Virtual Phantoms, Inc. The software utilizes male and female tissue equivalent phantoms of all ages and sizes including pregnant patients. The corresponding phantom was selected for every patient according to patient's tomographic parameters. Calculated organ doses were used to estimate the LAR of breast cancer according to BEIR VII Phase 2 report. It was found that radiation doses resulting from the same exam vary widely between different hospitals, depending on the parameters used and the type of scanner. For all patients, the breast organ dose ranged from 6.5 to 28 mGy per examination, with an average breast organ dose of 15 mGy. The effective dose from chest CT scan per examination ranged from 3 to 14.7 mSv with an average of 7 mSv. For younger females (15-29 years), the LAR of breast cancer risk was estimated to be around 0.05%. For older female patients (60-79 years), the risk was ~0.001%. It was found that LAR decreases remarkably with patient's age. Values obtained in this study vary between hospitals, they are generally low and consistent with other studies reported worldwide.