How much is too much? Systematic review of cumulative doses from radiological imaging and the risk of cancer in children and young adults

Optimizing radiation safety in dentistry: Clinical recommendations and regulatory considerations

BACKGROUND

The value of dental radiographs to oral health care decision making must be balanced with radiation safety to minimize patient exposure and occupational risk of oral health care providers. This review summarizes recommendations and regulatory guidance regarding dental radiography and cone-beam computed tomography. An expert panel presents recommendations on radiation safety, appropriate imaging practices, and reducing radiation exposure.

TYPES OF STUDIES REVIEWED

A systematic search run in Ovid MEDLINE, Embase, and Cochrane Database of Systematic Reviews identified relevant topical systematic reviews, organizational guidelines, and regulatory reviews published in the peer-reviewed literature since 2010. A supplemental search of the gray literature (eg, technical reports, standards, and regulations) identified topical nonindexed publications. Inclusion criteria required relevance to primary oral health care (ie, general or pediatric dentistry).

RESULTS

A total of 95 articles, guidance documents, and regulations met the inclusion criteria. Resources were characterized as applicable to all modalities, operator and occupational protection, dose reduction and optimization, and quality assurance and control.

PRACTICAL IMPLICATIONS

Understanding factors affecting imaging safety and applying fundamental principles of radiation protection consistent with federal, state, and local requirements are essential for limiting patient ionizing radiation exposure, in conjunction with implementing optimal imaging procedures to support prudent use of dental radiographs and cone-beam computed tomographic imaging. The regulatory guidance and best practice recommendations summarized in this article should be followed by dentists and other oral health care providers.

Effect of using different strips on reducing the most common error in panoramic imaging: A randomised controlled trial on palatoglossal air space shadow

INTRODUCTION

Panoramic radiography quality can be impaired by some errors such as positioning errors. Palatoglossal air space shadow error is one of the most common positioning errors and it is due to the tongue not sticking to the roof of the palate. Techniques used to deal with this error might help prevent unnecessary radiation to patients and save them time and money. The study aimed to investigate the effects of using celluloid matrix and edible tapes (fruit leather and chewing gum) on reducing the palatoglossal air space shadow error in panoramic imaging.

METHODS

In our study, 270 patients referred to the Department of Radiology were randomised into three groups: a control group, a celluloid matrix group and an edible tapes group. Before panoramic imaging, all patients were instructed to adhere their tongues to the roof of their mouths, with the distinction that for the celluloid matrix and edible tapes groups, patients were asked to place celluloid tapes, fruit leathers, or chewing gums on their tongues before doing so. The routine imaging process was then performed, and the results were compared across groups to evaluate the incidence of palatoglossal air space shadow error.

RESULTS

The number of error-free images in each fruit leather, chewing gum and celluloid tape group were significantly higher than the control group (all cases P < 0.05). The chances of error-free images in the fruit leather groups were the highest (9.57 times). The age (P = 0.136) and gender (P = 0.272) of patients had no significant effect on the results of interventions.

CONCLUSION

The application of fruit leathers, chewing gums and celluloid tapes reduced the palatoglossal air space shadow error of panoramic imaging.

Radiation Exposure from GEP NET Surveillance

BACKGROUND

Neuroendocrine tumors (NET) are neoplasms that secrete peptides and neuroamines. For gastroenteropancreatic (GEP) NET, surgical resection represents the only curative option. Ten-year imaging surveillance programs are recommended due to long time-to-recurrence following resection. We performed retrospective chart review evaluating radiation exposure and practice patterns from surveillance of completely resected GEP NET.

METHODS

We performed a retrospective cohort study of cases with well-differentiated GEP NET from January 2005 to July 2020. Location of primary, modality of imaging, and duration of follow-up were collected. Dosimetry data was collected to calculate effective dose.

RESULTS

62 cases were included with 422 surveillance scans performed. Cross-sectional imaging was used in 82% and functional imaging was used in 18% of scans. Mean number of scans per year was 1.25 (0.42-3). Mean total effective dose was 56.05 mSv (SD 45.56; 0 to 198 mSv) while mean total effective dose per year was 10.62 mSv (SD 9.35; 0 to 45 mSv). Over the recommended ten years of surveillance the estimated total effective dose was 106 mSv.

CONCLUSIONS

Surveillance of completely resected GEP NET results in cumulative radiation doses in the range associated with secondary malignancy development. Strategies to minimize radiation exposure in surveillance should be considered in future guideline development.

PET-CT for characterising TB infection (TBI) in immunocompetent subjects: a systematic review

Introduction. There is emerging evidence of a potential role for PET-CT scan as an imaging biomarker to characterise the spectrum of tuberculosis infection (TBI) in humans and animal models.Gap Statement. Synthesis of available evidence from current literature is needed to understand the utility of PET-CT for characterising TBI and how this may inform application of PET-CT in future TBI research.Aim. The aims of this review are to summarise the evidence of PET-CT scan use in immunocompetent hosts with TBI, and compare PET-CT features observed in humans and animal models.Methodology. MEDLINE, Embase and PubMed Central were searched to identify relevant publications. Studies were selected if they reported PET-CT features in human or animals with TBI. Studies were excluded if immune deficiency was present at the time of the initial PET-CT scan.Results. Six studies - four in humans and two in non-human primates (NHP) were included for analysis. All six studies used 2-deoxy-2-[18F]fluoro-d-glucose (2-[18F]FDG) PET-CT. Features of TBI were comparable between NHP and humans, with 2-[18F]FDG avid intrathoracic lymph nodes observed during early infection. Progressive TBI was characterised in NHP by increasing 2-[18F]FDG avidity and size of lesions. Two human studies suggested that PET-CT can discriminate between active TB and inactive TBI. However, data synthesis was generally limited by human studies including inconsistent and poorly characterised cohorts and the small number of eligible studies for review.Conclusion. Our review provides some evidence, limited primarily to non-human primate models, of PET-CT utility as a highly sensitive imaging modality to reveal and characterise meaningful metabolic and structural change in early TBI. The few human studies identified exhibit considerable heterogeneity. Larger prospective studies are needed recruiting well characterised cohorts with TBI and adopting a standardized PET-CT protocol, to better understand utility of this imaging biomarker to support future research.

Australian student radiographers' experiences and perspectives in general paediatric medical imaging examinations

INTRODUCTION

Paediatric patients differ from adult patients with respect to anatomy, examination factors, behaviour, and intellectual development, requiring dedicated specialised knowledge and expertise. In the absence of a formal dedicated paediatric medical imaging subspecialty, this study undertook to understand student radiographers' experiences and perspectives on paediatric medical imaging.

METHODS

The study entailed a descriptive cross-sectional survey design entailed a 51-item closed and open-ended response questionnaire using a total sampling method. Data were collected from both under- and postgraduate student radiographers who undertook clinical placement. Data interpretation and analysis involved statistical analysis of close-ended questions and thematic analysis of open-ended questions.

RESULTS

The overall response rate was 70%. Most participants acknowledged the importance of dedicated paediatric content as well as the theory content covered. The shortcoming in pre-placement practical component was overcome through varied approaches like observations and attempting through supervision whilst experiencing uncertainty, anxiety and felt unfair to risk the patient. As reported in literature like their qualified counterparts expressed similar challenges in technique adaptation, styles of interactions in gaining cooperation from both the children and parents. They also felt paediatric content and the practicals should be embedded throughout the course offering to not compromise the day-to-day service delivery.

CONCLUSIONS

The study findings iterate the importance paediatric imaging in the service delivery context. The importance of undertaking these examinations reliant on experiential learning is insufficient to bridge the gap of preparation prior to placement.

IMPLICATIONS FOR PRACTICE

Collaborative academic and clinical radiography education will ensure that radiography students' dedicated specialised paediatric imaging knowledge and experience are enhanced.

The Validity of Motion Capture Analysis System against the Gold Standard Long-Standing Radiography in the Measurement of Lower Extremity Alignment

Motion capture analysis (MCA) has the advantage of providing a static and dynamic leg axis analysis without radiation. Nevertheless, there is a lack of evidence regarding the accuracy of this technique. To test whether mechanical femorotibial axis angle (MAA) measurement recorded with a non-invasive MCA system is equal to the gold standard static long-standing full-leg radiographs (LSX) and if the degree of malalignment or other parameters (BMI, body mass, height, age) influence the accuracy, a total of 102 consecutive patients were examined using LSX and MCA. Static as well as all gait motion phases at 3 km/h were analyzed regarding the difference between the two angles. There was no statistical difference for MAA between LSX (MAArad) and MCA (MAAstat) (p = 0.091). There was a strong correlation (rs = 0.858, p < 0.001) between the two methods. The highest accuracy was detected for values of standing MCA. Also, the gait MCA values showed strong correlation with LSX but weaker correlation compared to standing MCA (initial swing rs = 0.549; terminal stance rs = 0.815; p < 0.001). BMI, body mass, and height did not influence the accuracy of MCA. MCA enables frontal alignment analysis with high accuracy and without the side effect of radiation.

Validity of sagittal thoracolumbar curvature measurement using a non-radiographic surface topography method

PURPOSE

To estimate the criterion validity of sagittal thoracolumbar spine measurement using a surface topography method in a clinical population against the gold standard and to estimate concurrent validity against two non-radiographic clinical tools.

METHODS

In this cross-sectional validity study, thoracolumbar curvature was measured in adults with spinal conditions recruited from a specialist orthopaedic hospital. A surface topography method using a Kinect sensor was compared to three other measurement methods: spinal radiograph (gold standard), flexicurve and digital inclinometer. Correlation coefficients and agreement between the measurement tools were analysed.

RESULTS

Twenty-nine participants (79% female) were included in criterion validity analyses and 38 (76% female) in concurrent validity analyses. The surface topography method was moderately correlated with the radiograph (r = .70, p < .001) in the thoracic spine, yet there was no significant correlation with the radiograph in the lumbar spine (r = .32, p = .89). The surface topography method was highly correlated with the flexicurve (rs = .91, p < .001) and digital inclinometer (r = .82, p < .001) in the thoracic spine, and highly correlated with the flexicurve (r = .74, p < .001) and digital inclinometer (r = .74, p < .001) in the lumbar spine.

CONCLUSIONS

The surface topography method showed moderate correlation and agreement in thoracic spine with the radiograph (criterion validity) and high correlation with the flexicurve and digital inclinometer (concurrent validity). Compared with other non-radiographic tools, this surface topography method displayed similar criterion validity for kyphosis curvature measurement.

CBTRUS Statistical Report: Pediatric Brain Tumor Foundation Childhood and Adolescent Primary Brain and Other Central Nervous System Tumors Diagnosed in the United States in 2014-2018

The CBTRUS Statistical Report: Pediatric Brain Tumor Foundation Childhood and Adolescent Primary Brain and Other Central Nervous System Tumors Diagnosed in the United States in 2014-2018 comprehensively describes the current population-based incidence of primary malignant and non-malignant brain and other CNS tumors in children and adolescents ages 0-19 years, collected and reported by central cancer registries covering approximately 100% of the United States population. Overall, brain and other CNS tumors are the most common solid tumor, the most common cancer, and the most common cause of cancer death in children and adolescents ages 0-19 years. This report aims to serve as a useful resource for researchers, clinicians, patients, and families.

Determining Out-of-Field Doses and Second Cancer Risk From Proton Therapy in Young Patients—An Overview

Proton therapy has the potential to provide survival and tumor control outcomes comparable and frequently superior to photon therapy. This has led to a significant concern in the medical physics community on the risk for the induction of second cancers in all patients and especially in younger patients, as they are considered more radiosensitive than adults and have an even longer expected lifetime after treatment. Thus, our purpose is to present an overview of the research carried out on the evaluation of out-of-field doses linked to second cancer induction and the prediction of this risk. Most investigations consisted of Monte Carlo simulations in passive beam facilities for clinical scenarios. These works established that equivalent doses in organs could be up to 200 mSv or 900 mSv for a brain or a craniospinal treatment, respectively. The major contribution to this dose comes from the secondary neutrons produced in the beam line elements. Few works focused on scanned-beam facilities, but available data show that, for these facilities, equivalent doses could be between 2 and 50 times lower. Patient age is a relevant factor in the dose level, especially for younger patients (by means of the size of the body) and, in addition, in the predicted risk by models (due to the age dependence of the radiosensitivity). For risks, the sex of the patient also plays an important role, as female patients show higher sensitivity to radiation. Thus, predicted risks of craniospinal irradiation can range from 8% for a 15-year-old male patient to 58% for a 2-year-old female patient, using a risk model from a radiological protection field. These values must be taken with caution due to uncertainties in risk models, and then dosimetric evaluation of stray radiation becomes mandatory in order to complement epidemiological studies and be able to model appropriate dose–response functions for this dose range. In this sense, analytical models represent a useful tool and some models have been implemented to be used for young patients. Research carried out so far confirmed that proton beam therapy reduces the out-of-field doses and second cancer risk. However, further investigations may be required in scanned-beam delivery systems.

Impact of dose reducing software on patient and staff temple dose during fluoroscopically guided pacemaker insertion, closure devices implantation and coronary angiography procedures

The aim of this study is to investigate the effectiveness of dose reducing software (ClarityIQ) on patient and staff dose during fluoroscopically guided cardiac procedures. Dose measurements were collected in a room without dose reducing software (n = 157) and compared with similar procedures performed in two rooms with the software (n = 1141). Procedures included diagnostic coronary angiography, percutaneous coronary intervention, deployment of cardiac closure devices (for occlusion of atrial septal defect, patent foramen ovale, and atrial appendage) and insertion of permanent pacemakers. The dose reducing software was found to be effective in reducing patient and staff dose by approximately 50%. This study has added to the limited literature reporting on the capability of dose reducing software to decrease radiation exposure during the implantation of cardiac closure devices, as well as demonstrating a reduction in dose to the cardiologist and nursing staff. Administrators should ensure timely upgrades to angiographic equipment to safeguard patients and staff against the potentially adverse effects of radiation exposure. Regardless of the use of dose reducing software, the mean occupational dose during closure devices was in descending order scout > scrub > cardiologist. Scrub nurse dose was found to be higher than the cardiologist during closure devices (0.98/0.26 μSv) and diagnostic coronary angiograms (1.51/0.82 μSv). Nursing staff should be aware that their levels of radiation dose during some cardiac procedures may come close to or even exceed that of the cardiologist.

Management of post-septal complications of acute rhinosinusitis in children: A 14-year experience in a tertiary hospital

INTRODUCTION

Acute rhinosinusitis accounts for most of the cases of orbital infections and is the most common cause of periorbital oedema in children. Up to 10% of patients with orbital complications of acute rhinosinusitis may experience vision loss and other complications such as meningitis, intracranial abscess or even death. Therefore, these patients require prompt diagnosis and proper treatment.

OBJECTIVES

This study aims to report the clinical presentation and management of post-septal orbital complications of acute rhinosinusitis in the paediatric population.

MATERIALS AND METHODS

A retrospective medical chart review of all children aged under 18 years old who were diagnosed with post-septal orbital complications of acute rhinosinusitis at a tertiary academic hospital, between 01/2007 and 12/2020. Patients were grouped according to the Chandler Classification (groups 2-5).

RESULTS

Fifty-five children (mean age of 6.91 ± 4.61 years) fulfilled the entry criteria for post-septal orbital complications of acute rhinosinusitis, based on clinical evaluation by an otorhinolaryngologist and CT-scan findings. Forty (72.72%) patients were also evaluated by an ophthalmologist. Most patients were male (76.36%). Twenty-four patients had post-septal cellulitis (43.63%), 21 patients had a subperiosteal abscess (38.18%) and 10 patients had an orbital abscess (18.18%). Eyelid swelling was the most frequent sign, followed by fever. Microbiology varied considerably and gram-positive agents were clearly predominant. Eighteen (32.73%) patients had been treated with oral antibiotics prior to hospital admission, exhibiting a significantly higher risk of recurrence of orbital infection (p = 0.020). Ethmoid and maxillary sinuses were the most involved paranasal sinuses (90.91%). Thirty-three patients (60%) were successfully treated medically, and 22 patients (40%) required surgical drainage. Seven patients (12.73%) developed further complications and six recovered without sequelae. The mean length of hospital stay was 8.0 ± 5.0 days and recurrence of orbital infection occurred in six patients (10.91%). The absolute neutrophil blood count was significantly different amongst Chandler groups (p = 0.021), with higher counts in patients with subperiosteal abscess. The duration of hospitalization was significantly higher in patients submitted to surgery (p < 0.001).

CONCLUSION

Post-septal orbital complications of acute rhinosinusitis are infrequent but dangerous events in the paediatric population. Close collaboration with Ophtalmology is paramount, as the child's vision is at risk. Eyelid swelling and proptosis are early signs. CT-scan imaging plays an invaluable role in the diagnosis and decision-making. Predictive indicators for surgery were not found. However, emergency endoscopic nasal surgery with abscess drainage should be considered whenever vision is at risk, if there is no improvement after aggressive medical treatment, and in cases of intracranial complications.

The cumulative radiation dose paradigm in pediatric imaging

Medical imaging professionals have an accountability for both quality and safety in the care of patients that have unexpected or anticipated repeated imaging examinations that use ionizing radiation. One measure in the safety realm for repeated imaging is cumulative effective dose (CED). CED has been increasingly scrutinized in patient populations, including adults and children. Recognizing the challenges with effective dose, including the cumulative nature, effective dose is still the most prevalent exposure currency for recurrent imaging examinations. While the responsibility for dose monitoring incorporates an element of tracking an individual patient cumulative radiation record, a more complex aspect is what should be done with this information. This challenge also differs between the pediatric and adult population, including the fact that high cumulative doses (e.g.,>100 mSv) are reported to occur much less frequently in children than in the adult population. It is worthwhile, then, to review the general construct of CED, including the comparison between the relative percentage occurrence in adult and pediatric populations, the relevant pediatric medical settings in which high CED occurs, the advances in medical care that may affect CED determinations in the future, and offer proposals for the application of the CED paradigm, considering the unique aspects of pediatric care.

Radiation protection perspective to recurrent medical imaging: what is known and what more is needed?

This review summarises the current knowledge about recurrent radiological imaging and associated cumulative doses to patients. The recent conservative estimates are for around 0.9 million patients globally who cumulate radiation doses above 100 mSv, where evidence exists for cancer risk elevation. Around one in five is estimated to be under the age of 50. Recurrent imaging is used for managing various health conditions and chronic diseases such as malignancies, trauma, end-stage kidney disease, cardiovascular diseases, Crohn's disease, urolithiasis, cystic pulmonary disease. More studies are needed from different parts of the world to understand the magnitude and appropriateness. The analysis identified areas of future work to improve radiation protection of individuals who are submitted to frequent imaging. These include access to dose saving imaging technologies; improved imaging strategies and appropriateness process; specific optimisation tailored to the clinical condition and patient habitus; wider utilisation of the automatic exposure monitoring systems with an integrated option for individual exposure tracking in standardised patient-specific risk metrics; improved training and communication. The integration of the clinical and exposure history data will support improved knowledge about radiation risks from low doses and individual radiosensitivity. The radiation protection framework will need to respond to the challenge of recurrent imaging and high individual doses. The radiation protection perspective complements the clinical perspective, and the risk to benefit analysis must account holistically for all incidental and long-term benefits and risks for patients, their clinical history and specific needs. This is a step toward the patient-centric health care.

A Single-Institution Experience in the Use of Chest Radiographs for Hospitalized Children Labeled as Asthma Exacerbation

Background: Risks of diagnostic radiation have become more notable lately, particularly in young children with chronic medical conditions. This study reports on the cumulative radiation from chest radiographs in children with asthma. Its main purpose was to review our current practice and suggest minimizing the use of chest radiographs. Methods: The study was retrospective and conducted at a pediatric tertiary center. Eligibility criteria included children 2-15 y, admitted between January 2017 and December 2018 for asthma management. Results: Of the 643 children admitted as "asthma exacerbation," 243 [40% females; age (mean ± SD) 5.4±3.3 y] met the study criteria for inclusion. Ninety-two (38%) children had a temperature of 38.8±0.7°C on the day of admission. Antibiotics were prescribed for 148 (61%) children, mainly for presumed pneumonia. Chest radiographs were requested for 214 (88%) children, mainly on the day of admission. Only 38 (18%) chest radiographs showed focal/multifocal pneumonia justifying antibiotic use. Significant predictors for requesting chest radiographs were antibiotic use for presumed pneumonia, lower oxygen saturation at presentation, and a requested blood culture. The rate of chest radiographs per year was negatively related to the child's age; the younger the child the higher the rate (model coefficient -0.259, P < 0.001). For children < 5 y, the rate of chest radiographs was 1.39 ± 1.21/y and radiation dose 0.028 ± 0.025 mSv/y. The corresponding rates for children ≥5 y were 0.78 ± 0.72/y and 0.008 ± 0.007 mSv/y, respectively (P < 0.001). Conclusion: Chest radiographs were commonly requested for children with asthma, especially younger children. Prospective studies are necessary to measure the impact of this practice on the children's health.

Comparison of flexible nasopharyngoscopy with plain radiograph in the assessment of children with adenoid hypertrophy

Background:

Obstructive adenoid hypertrophy is one of the commonest disorder seen in paediatric otorhinolaryngology clinics. It has a wide range of complications that can lead to cardiopulmonary and developmental problems; hence, early diagnosis and treatment are paramount in preventing the complications. Several modalities for the assessment of adenoid hypertrophy have been described in the literature, of which plain radiograph and flexible nasopharyngoscopy are the most popular. In this study, traditional method of evaluating adenoid hypertrophy (plain radiograph) has been compared with newer flexible nasopharyngoscopy.

Materials and Methods:

This is a cross-sectional study of randomly selected children with clinical diagnosis of obstructive adenoid disease. All eligible participants underwent clinical examinations, flexible nasopharyngoscopy and postnasal space X-ray. The findings were compared using the chi-square test and Pearson’s correlation test.

Results:

The age of the participants ranged between 2 and 10 years with mean of 4.5 ± 2.5 years. There were 79 (56.4%) males and 61 (43.6%) females. The adenoid hypertrophy observed using flexible nasopharyngoscopy among the participants ranged between 20 and 90% with mean of 67.4 ± 15.4%. The adenoid enlargement measured using adenoidal–nasopharyngeal ratio on plain radiograph ranged between 0.40 and 0.96 with mean of 0.7 ± 0.09. The Pearson’s correlation test revealed strong correlation between flexible nasopharyngoscopy and plain radiograph (r = 0.858, P = .000), and there was statistically significant association between the two methods (χ² = 148.8, P = .000).

Conclusion:

There was a strong correlation between flexible nasopharyngoscopy and plain radiograph of the postnasal space in the assessment of obstructive adenoid disease in children.