Theoretical increase of thyroid cancer induction from cervical spine multidetector computed tomography in pediatric trauma patients. J Trauma Acute Care Surg. 2012;72:403-409. [PMID: 22327982 DOI: 10.1097/ta.0b013e31823a4bd7]

Pediatric Cervical Spine Injury Following Blunt Trauma in Children Younger Than 3 Years: The PEDSPINE II Study

Importance

There is variability in practice and imaging usage to diagnose cervical spine injury (CSI) following blunt trauma in pediatric patients.

Objective

To develop a prediction model to guide imaging usage and to identify trends in imaging and to evaluate the PEDSPINE model.

Design, Setting, and Participants

This cohort study included pediatric patients (<3 years years) following blunt trauma between January 2007 and July 2017. Of 22 centers in PEDSPINE, 15 centers, comprising level 1 and 2 stand-alone pediatric hospitals, level 1 and 2 pediatric hospitals within an adult hospital, and level 1 adult hospitals, were included. Patients who died prior to obtaining cervical spine imaging were excluded. Descriptive analysis was performed to describe the population, use of imaging, and injury patterns. PEDSPINE model validation was performed. A new algorithm was derived using clinical criteria and formulation of a multiclass classification problem. Analysis took place from January to October 2022.

Exposure

Blunt trauma.

Main Outcomes and Measures

Primary outcome was CSI. The primary and secondary objectives were predetermined.

Results

The current study, PEDSPINE II, included 9389 patients, of which 128 (1.36%) had CSI, twice the rate in PEDSPINE (0.66%). The mean (SD) age was 1.3 (0.9) years; and 70 patients (54.7%) were male. Overall, 7113 children (80%) underwent cervical spine imaging, compared with 7882 (63%) in PEDSPINE. Several candidate models were fitted for the multiclass classification problem. After comparative analysis, the multinomial regression model was chosen with one-vs-rest area under the curve (AUC) of 0.903 (95% CI, 0.836-0.943) and was able to discriminate between bony and ligamentous injury. PEDSPINE and PEDSPINE II models' ability to identify CSI were compared. In predicting the presence of any injury, PEDSPINE II obtained a one-vs-rest AUC of 0.885 (95% CI, 0.804-0.934), outperforming the PEDSPINE score (AUC, 0.845; 95% CI, 0.769-0.915).

Conclusion and Relevance

This study found wide clinical variability in the evaluation of pediatric trauma patients with increased use of cervical spine imaging. This has implications of increased cost, increased radiation exposure, and a potential for overdiagnosis. This prediction tool could help to decrease the use of imaging, aid in clinical decision-making, and decrease hospital resource use and cost.

The uncertainty of thyroid dose estimate in chest CT

Dose to the thyroid from helical chest CT can vary significantly due to the random tube start point, pitch factor, thyroid position relative to the isocenter, and beam width. We used optically stimulated luminescence dosimeters (OSLDs) and an adult anthropomorphic phantom to investigate the uncertainty of thyroid dose estimate. Maximum gap or overlap in the helical beam was estimated using the above factors. Using the maximum gap/overlap over the thyroid, different possible scenarios were simulated and the degree of missed thyroid tissue by the primary beam was estimated. Results showed a variation of >30% in the average thyroid dose, and >50% if a single dosimeter was used to determine dose to the thyroid. Furthermore, measured doses were compared to those calculated by Monte Carlo simulation software, which automatically matches the anatomy of the localizer radiograph with the stylized computational phantom used for dose calculation. The difference was significant: the dose given by the Monte Carlo software was ∼50% lower than the average dose measured with the phantom in all three chest protocols. In addition, the software does not take the effect of the random tube start angle into account.

Cervical Spine Injury Risk Factors in Children With Blunt Trauma

BACKGROUND

Adult prediction rules for cervical spine injury (CSI) exist; however, pediatric rules do not. Our objectives were to determine test accuracies of retrospectively identified CSI risk factors in a prospective pediatric cohort and compare them to a de novo risk model.

METHODS

We conducted a 4-center, prospective observational study of children 0 to 17 years old who experienced blunt trauma and underwent emergency medical services scene response, trauma evaluation, and/or cervical imaging. Emergency department providers recorded CSI risk factors. CSIs were classified by reviewing imaging, consultations, and/or telephone follow-up. We calculated bivariable relative risks, multivariable odds ratios, and test characteristics for the retrospective risk model and a de novo model.

RESULTS

Of 4091 enrolled children, 74 (1.8%) had CSIs. Fourteen factors had bivariable associations with CSIs: diving, axial load, clotheslining, loss of consciousness, neck pain, inability to move neck, altered mental status, signs of basilar skull fracture, torso injury, thoracic injury, intubation, respiratory distress, decreased oxygen saturation, and neurologic deficits. The retrospective model (high-risk motor vehicle crash, diving, predisposing condition, neck pain, decreased neck mobility (report or exam), altered mental status, neurologic deficits, or torso injury) was 90.5% (95% confidence interval: 83.9%-97.2%) sensitive and 45.6% (44.0%-47.1%) specific for CSIs. The de novo model (diving, axial load, neck pain, inability to move neck, altered mental status, intubation, or respiratory distress) was 92.0% (85.7%-98.1%) sensitive and 50.3% (48.7%-51.8%) specific.

CONCLUSIONS

Our findings support previously identified pediatric CSI risk factors and prospective pediatric CSI prediction rule development.

CT scans to exclude spine fractures in children after negative radiographs may lead to increase in future cancer risk

INTRODUCTION

National Institute for Health and Care Excellence guidelines recommend computed tomography (CT) scanning for children who fulfill the criteria of significant mechanism or focal spinal pathology. Resulting radiation might subsequently increase the risk of cancer.

METHODS

Children with spinal CT scans and radiographs from August 2015 to July 2017 were reviewed retrospectively. Data were obtained from the formal radiology reports and case notes. The radiation exposure and risk of cancer were estimated.

RESULTS

Thirty-five children had spine CT scans, and 757 spine radiographs were undertaken. Nine (25%) children had their spines scanned as a part of trauma series due to a severe mechanism of injury. Two patients (6%) had abnormalities in their radiographs prior to CT scans, and the rest were obtained to exclude injuries with negative radiographs. The mean radiation dose from CT scan was 20.3 (SD: 11.3) mSV. The relative risk of missing a spine fracture in a child with a normal radiograph was not statistically significant (RR1.14 95% CI 0.3-4.3 and P = 0.8), and the NNT for detecting a spine fracture with a normal radiograph with further CT scan was 56. The mean lifetime additional cancer risk with CT scan in this group was 0.37%. A significant (P < 0.0001) positive correlation between the radiation dose and increased cancer risk was found.

CONCLUSION

Children with clinically suspected spinal fracture in the absence of red flag signs/symptoms and negative radiographs might be considered for alternative assessments or investigations to reduce the risk of CT-related radiation hazards.

Epidemiology of vertebral fractures in pediatric and adolescent patients

Spinal injuries in children and adolescents are rare injuries, but consequences for the growing skeleton can be devastating. Knowledge of accident causes, clinical symptoms and diagnostics should be part of every trauma department treating these patients. We retrospectively analyzed patients with radiographically proven vertebral fractures of the spine. After clinical examination and tentative diagnosis the fractures and injuries were proven with conventional X-ray, computed tomography (CT) scans or magnetic resonance imaging (MRI). The study included 890 fractures in 546 patients with an average age of 12.8±6.2 (6.6-19.4) years. Females had an average age of 13.7±6.3 (7.4-20.0) years, whereas males were on average 12.0 (6.0-18.0) years old. Fall from height (58%) was the main cause of accident and the most common region of fracture was the thoracolumbar spine with a shift towards the thoracic spine the more fractures occurred. Merely 3.7% of all patients required operative treatment. If a vertebral fracture is found in children and adolescents, it is highly recommended to exclude synchronous additional spine fractures in other levels; prevention should concentrate on fall and traffic accidents.

Imaging investigations in Spine Trauma: The value of commonly used imaging modalities and emerging imaging modalities

Traumatic spine injuries can be devastating for patients affected and for health care professionals if preventable neurological deterioration occurs. This review discusses the imaging options for the diagnosis of spinal trauma. It lays out when imaging is appropriate and when it is not. It discusses strength and weakness of available imaging modalities. Advanced techniques for spinal injury imaging will be explored. The review concludes with a review of imaging protocols adjusted to clinical circumstances.

Radiological assessment of paediatric cervical spine injury in blunt trauma: the potential impact of new NICE guidelines on the use of CT

AIM

To determine the potential effect of changes to the National Institute for Health and Care Excellence (NICE) guidelines to the use of computed tomography (CT) in the assessment of suspected paediatric cervical spine (c-spine) injury.

MATERIAL AND METHODS

A 5 year retrospective study was conducted of c-spine imaging in paediatric (<10 years) patients presenting following blunt trauma at a Level 1 trauma centre in London. All patients under the age of 10 years who underwent any imaging of the c-spine following blunt trauma were included. Clinical data relating to the presenting signs and symptoms were obtained from the retrospective review of electronic records and paper notes. This was then applied to the previous NICE guideline (CG56) and to the new NICE guideline (CG176). Patients with incomplete data were excluded.

RESULTS

Two hundred and seventy-eight patients <10 years underwent imaging of the c-spine following blunt trauma. Two hundred and seventy (97.12%) examinations had complete data and were included in further analysis. One hundred and forty-nine (55.19%) met the criteria for a CT of the c-spine under NICE CG56, whereas 252 (93.33%) met the updated NICE CG176 criteria for c-spine CT. Five (1.85%) patients had a c-spine injury and met the criteria under both CG56 and CG176 NICE guidelines.

CONCLUSION

Recent changes to NICE Head Injury Guidelines relating to radiological assessment of paediatric c-spine following blunt trauma are likely to result in an increased usage of CT as the initial radiological investigation over plain radiographs, without an apparent increase in specificity in the present series.

Femur fractures should not be considered distracting injuries for cervical spine assessment

INTRODUCTION

The National Emergency X-Radiography Utilization Study (NEXUS) clinical decision rule is extremely sensitive for clearance of cervical spine (C-spine) injury in blunt trauma patients with distracting injuries.

OBJECTIVES

We sought to determine whether the NEXUS criteria would maintain sensitivity for blunt trauma patients when femur fractures were not considered a distracting injury and an absolute indication for diagnostic imaging.

METHODS

We retrospectively analyzed blunt trauma patients with at least 1 femur fracture who presented to our emergency department as trauma activations from 2009 to 2011 and underwent C-spine injury evaluation. Presence of C-spine injury requiring surgical intervention was evaluated.

RESULTS

Of 566 trauma patients included, 77 (13.6%) were younger than 18 years. Cervical spine injury was diagnosed in 53 (9.4%) of 566. A total of 241 patients (42.6%) had positive NEXUS findings in addition to distracting injury; 51 (21.2%) of these had C-spine injuries. Of 325 patients (57.4%) with femur fractures who were otherwise NEXUS negative, only 2 (0.6%) had C-spine injuries (95% confidence interval [CI], 0.2%-2.2%); both were stable and required no operative intervention. Use of NEXUS criteria, excluding femur fracture as an indication for imaging, detected all significant injuries with a sensitivity for any C-spine injury of 96.2% (95% CI, 85.9%-99.3%) and negative predictive value of 99.4% (95% CI, 97.6%-99.9%).

CONCLUSIONS

In our patient population, all significant C-spine injuries were identified by NEXUS criteria without considering the femur fracture a distracting injury and indication for computed tomographic imaging. Reconsidering femur fracture in this context may decrease radiation exposure and health care expenditure with little risk of missed diagnoses.

Cervical spine imaging in hospitalized children with traumatic brain injury

OBJECTIVES

The purposes of this study, in children with traumatic brain injury (TBI), to describe cervical spine imaging practice, to assess for recent changes in imaging practice, and to determine whether cervical spine computed tomography (CT) is being used in children at low risk for cervical spine injury.

METHODS

The setting was children's hospitals participating in the Pediatric Health Information System database, from January 2001 to June 2011. Participants were children (younger than 18 y) with TBI who were evaluated in the emergency department, admitted to the hospital, and received a head CT scan on the day of admission. The primary outcome measures were cervical spine imaging studies. This study was exempted from institutional review board assessment.

RESULTS

A total of 30,112 children met study criteria. Overall, 52% (15,687/30,112) received cervical spine imaging. The use of cervical spine radiographs alone decreased between 2001 (47%) and 2011 (23%), with an annual decrease of 2.2% (95% confidence interval [CI], 1.1%-3.3%), and was largely replaced by an increased use of CT, with or without radiographs (8.6% in 2001 and 19.5% in 2011, with an annual increase of 0.9%; 95% CI, 0.1%-1.8%). A total of 2545 children received cervical spine CT despite being discharged alive from the hospital in less than 72 hours, and 1655 of those had a low-risk mechanism of injury.

CONCLUSIONS

The adoption of CT clearance of the cervical spine in adults seems to have influenced the care of children with TBI, despite concerns about radiation exposure.

The benefit of neck computed tomography compared with its harm (risk of cancer)

BACKGROUND

The purpose of this study was to compare the benefit of neck computed tomography (CT) of identifying important cervical spine injuries (CSIs) with its harm of radiation exposure and cancer risk.

METHODS

A PubMed search for published studies relating to CSI in trauma, cervical spine imaging, CT, and cancer risk was conducted. Article abstracts were reviewed, and selected published studies relating to the study objective were retrieved.

RESULTS

Of 100,000 trauma patients, neck CT scans were obtained in 3,767 to 26,785 patients. Of 100,000 patients with trauma on whom a neck CT scan was performed, a CSI was identified in 2,470 to 33,898 patients. Clinically important CSI ranged from 4,724 to 27,119 per 100,000 CT scans. For every 100,000 neck CT scans performed, additional cancer cases occur in a low end estimate of a thyroid cancer cases to a high end estimate of 100 male and 700 female cancer cases. In females, cancer risks are higher than in males, and these are closer to, but still less than, the incidence of clinically important CSI found by CT.

CONCLUSION

CT's benefit of identifying important CSIs in the published studies exceeds its cancer harm risk. However, at their extremes, the numbers are disturbingly close. Limiting neck CT scanning to a higher-risk group would increase the gap between benefit and harm, whereas performing CT routinely on low-risk cases approaches a point where its harm equals or exceeds its benefit.

LEVEL OF EVIDENCE

Systematic review, level IV.

Trends in musculoskeletal imaging in trauma patients: how has our practice changed over time?

OBJECTIVES

The purpose of the study was to review diagnostic imaging in trauma patients. We hypothesized that diagnostic musculoskeletal imaging has increased over time, but at a lesser rate than radiography performed for other purposes. Two trauma centers were compared.

DESIGN

Retrospective multicenter study.

SETTING

Two level 1 trauma centers.

PATIENTS/PARTICIPANTS

Five hundred patients per year from each trauma centers were reviewed for 2002, 2005, and 2008.

MAIN OUTCOME MEASUREMENTS

Effective doses [millisieverts (mSv)] and total charges for radiography were calculated.

RESULTS

Most imaging was performed within 24 hours of injury. In 2002, 15% of all radiographic studies were computed tomography (CT) scans compared with 33% in 2008 (P < 0.0001). Center 1 used more CT, and center 2 used more projection (plain) radiography. The percentage of musculoskeletal CTs increased from 26% in 2002 to 49% in 2008 (P < 0.0001), without change in patient acuity. The mean effective dose per patient was 17.3 mSv in 2002, 30.0 mSv in 2005, and 34.1 mSv in 2008 (P < 0.001). The percentage of total dose attributable to musculoskeletal studies increased from 25% in 2002, to 29% in 2005, and 31% in 2008 (P < 0.001). Mean total charges per patient were $4529 in 2002; $6922 in 2005; and $7750 in 2008 (P < 0.001), with higher 2008 mean charges at center 1 versus 2 ($8694 vs. $6806, P = 0.001), primarily because of more CT scans.

CONCLUSIONS

The number of diagnostic imaging tests, radiation dose, and related charges in trauma patients increased over time at both trauma centers, with CT scans accounting for most of the radiation dose and costs. A shift toward more advanced imaging from conventional projection radiography was noted at both trauma centers. Effective dose per patient more than doubled over the course of study at center 1. By 2008, half of all radiographic studies were for musculoskeletal purposes. Previous studies have suggested an increased risk of cancer with exposures of 20-40 mSv, making the mean total radiation doses in excess of 30.0 mSv since 2005 of great concern. Variability in ordering patterns between the 2 centers with similar patient acuity suggests opportunity for discussion about indications for utilization, which could result in lower radiation doses and fewer expenses.

Vertebral artery anomalies at the craniovertebral junction in the US population

STUDY DESIGN

Retrospective review.

OBJECTIVE

To evaluate the prevalence of anatomical variations of the vertebral artery at the craniovertebral junction and the posterior arch of the atlas in the US population.

SUMMARY OF BACKGROUND DATA

Recent studies from Asia have reported a 5% to 10% prevalence of a persistent first intersegmental vertebral artery and 1% to 2% prevalence of a fenestrated artery. These anomalous vertebral artery courses lie directly over the starting point for atlas lateral mass screw insertion. The relatively high reported prevalence of these anomalies suggests that routine preoperative computed tomographic angiogram be considered prior to upper cervical fixation. We have not observed this anomaly as commonly as reported.

METHODS

The authors analyzed the records of 975 patients from a level I trauma center and adjacent university hospital who underwent computed tomographic angiography to evaluate the incidence of anomalous variations in the third segment of the vertebral artery. These results were compared with similar studies performed in Korea and Japan.

RESULTS

The mean age of the patients was 52.9 years. The ethnic distribution of the patients was as follows: 69.3% of the patients were Caucasian, 11% Asian, 10.8% African American, and 6% Hispanic. The prevalence of a persistent intersegmental artery was 0.01% (1/975); a fenestrated vertebral artery was 0.01% (1/975); and origin of a posterior inferior cerebellar artery was 0.4% (4/975). The incidence of these anomalies was significantly lower than those previously published from Korea and Japan.

CONCLUSION

Vertebral artery course anomalies in the upper cervical spine were rare (0.42%) in our patient population. This finding contrasts with recent published reports from Asia, citing as high as a 10% rate of vertebral artery presence over the starting point for C1 lateral mass screw insertion. On the basis of the infrequent occurrence of this anomaly, we do not recommend routine computed tomographic angiography when planning upper cervical instrumentation.

LEVEL OF EVIDENCE

N/A

Risk of malignancy associated with head and neck CT in children: a systematic review

OBJECTIVE

To perform a systematic review to evaluate the risk of malignancy associated with computed tomography (CT) of the head and/or neck in infants, children, and adolescents.

DATA SOURCES

Pubmed, EMBASE, and the Cochrane Library were assessed from the date of their inception to January 2014. Additionally, manual searches of bibliographies were performed and topic experts were contacted.

REVIEW METHODS

Data were obtained from studies measuring or estimating the risks of malignancy associated with radiation from head and/or neck CT in pediatric populations according to an a priori protocol. Two independent evaluators corroborated the extracted data.

RESULTS

There were 16 criterion-meeting studies that included data from n = 858,815 patients. The radiation-related risk of malignancy was estimated using primary patient data for both the exposure and outcome in a minority of studies, with most analyses utilizing mathematical modeling techniques. The data regarding otolaryngology-specific studies were limited and suggested a borderline significant increase in the risk of all combined cancers after facial CT (incidence rate ratio [IRR] = 1.14; 95% CI, 1.01-1.28) and neck/spine CT (IRR = 1.13; 95% CI, 1.00-1.28). Cohort data suggest that 1 excess brain malignancy occurred after 4000 brain CTs (40 mSv per scan) and that the estimated risk in the 10 years following CT exposure was 1 brain tumor per 10,000 patients exposed to a 10 mGy scan at less than 10 years of age.

CONCLUSION

Detailed understanding of any potential malignancy risk associated with pediatric imaging of the head and neck furthers our ability to engage in rational, shared, informed decision making with families considering CT scan.

Risk of radiation-induced malignancies from CT scanning in children who underwent shunt treatment before 6 years of age: a retrospective cohort study with a minimum 10-year follow-up

OBJECT

A number of mathematical models predict the risk of future cancer from the ionizing radiation exposure of CT scanning. The predictions are alarming. Some models predict 29,000 future cancers and 14,500 deaths in the US will be directly caused by 1 year's worth of CT scanning. However, there are very few clinical data to justify or refute these claims. Young children are theoretically highly susceptible to the damaging effects of radiation. In this study, the authors examined children who underwent CSF shunt placement before 6 years of age. The authors chose to study shunt-treated patients with the assumption that these patients would undergo future imaging, facilitating surveillance. They chose a study period of 1991-2001 to allow more than 10 years of follow-up data.

METHODS

The authors studied 104 consecutive children who underwent CSF shunt placement prior to 6 years of age and who had at least 10 years of follow-up data. Sixty-two of these patients underwent shunt placement prior to 1 year of age. The age at the initial scanning session, the number of future CT scanning sessions, diagnosis, and results of any future studies were recorded. The age-specific radiation dose was calculated for children younger than 1 year. Children younger than 1 year at the time of shunt placement were evaluated separately, based on the assumption that they represented the highest risk cohort. The authors examined all data for any evidence of future leukemia or head/neck tumor (benign or malignant).

RESULTS

These children underwent a total of 1584 CT scanning sessions over a follow-up period of 1622 person-years. A total of 517 scanning sessions were performed prior to 6 years of age, including 260 in the 1st year of life. Children who underwent shunt placement before 1 year of age underwent an average of 16.3 ± 13.5 CT sessions (range 1-41). Children undergoing placement between 1 and 6 years of age received an average of 14.1 ± 12.5 CT studies (range 5-52). There were no subsequent tumors (benign or malignant) or leukemia detected.

CONCLUSIONS

Previously published models predict a significant number of future cancers directly caused by CT scanning. However, there are very few published clinical data. In the authors' study, zero future radiation-induced malignancies were detected after routine CT scanning in a high-risk group. While the authors do not consider their single-institution study adequate to define the actual risk, their data suggest that the overall risk is low. The authors hope this study encourages future collaborative efforts to define the actual risk to patients.

Radiation risks associated with serial imaging in colorectal cancer patients: Should we worry?

To provide an overview of the radiation related cancer risk associated with multiple computed tomographic scans required for follow up in colorectal cancer patients. A literature search of the PubMed and Cochrane Library databases was carried out and limited to the last 10 years from December 2012. Inclusion criteria were studies where computed tomographic scans or radiation from other medical imaging modalities were used and the risks associated with ionizing radiation reported. Thirty-six studies were included for appraisal with no randomized controlled trials. Thirty-four of the thirty-six studies showed a positive association between medical imaging radiation and increased risk of cancer. The radiation dose absorbed and cancer risk was greater in children and young adults than in older patients. Most studies included in the review used a linear, no-threshold model to calculate cancer risks and this may not be applicable at low radiation doses. Many studies are retrospective and ensuring complete follow up on thousands of patients is difficult. There was a minor increased risk of cancer from ionizing radiation in medical imaging studies. The radiation risks of low dose exposure (< 50 milli-Sieverts) are uncertain. A clinically justified scan in the context of colorectal cancer is likely to provide more benefits than harm but current guidelines for patient follow up will need to be revised to accommodate a more aggressive approach to treating metastatic disease.