Imaging of pediatric pulmonary tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Pediatric pulmonary malignancy can be primary or metastatic, with the latter being by far the more common. With a few exceptions, there are no well-established evidence-based guidelines for imaging pediatric pulmonary malignancies, although computed tomography (CT) is used in almost all cases. The aim of this article is to provide general imaging guidelines for pediatric pulmonary malignancies, including minimum standards for cross-sectional imaging techniques and specific imaging recommendations for select entities.

Comparison of the different imaging modalities used to image pediatric oncology patients: A COG diagnostic imaging committee/SPR oncology committee white paper

Diagnostic imaging is essential in the diagnosis and management, including surveillance, of known or suspected cancer in children. The independent and combined roles of the various modalities, consisting of radiography, fluoroscopy, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine (NM), are both prescribed through protocols but also function in caring for complications that may occur during or subsequent to treatment such as infection, bleeding, or organ compromise. Use of a specific imaging modality may be based on situational circumstances such as a brain CT or MR for a new onset seizure, chest CT for respiratory signs or symptoms, or US for gross hematuria. However, in many situations, there are competing choices that do not easily lend themselves to a formulaic approach as options; these situations depend on the contributions of a variety of factors based on a combination of the clinical scenario and the strengths and limitations of the imaging modalities. Therefore, an improved understanding of the potential influence of the imaging decision pathways in pediatric cancer care can come from comparison among the individual diagnostic imaging modalities. The purpose of the following material to is to provide such a comparison. To do this, pediatric imaging content experts for the individual modalities of radiography and fluoroscopy, US, CT, MRI, and NM will discuss the individual modality strengths and limitations.

Imaging findings of COPA Syndrome

BACKGROUND

Autosomal dominant mutations in the coatomer-associated protein alpha (COPA) gene cause an immune dysregulation disorder associated with pulmonary hemorrhage, lymphoid hyperplasia, arthritis, and glomerulonephritis.

OBJECTIVE

To describe the thoracic, musculoskeletal, and renal imaging findings of COPA syndrome with a focus on the evolution of the pulmonary findings.

MATERIALS AND METHODS

With approval of the Institutional Review Board, consensus retrospective review of findings on chest radiography and computed tomography (CT), musculoskeletal radiography and magnetic resonance imaging (MRI), and renal ultrasound (US) was performed for pediatric COPA syndrome patients. COPA syndrome patients < 18 years of age presenting between 1992 and 2019 were identified from an institutional rheumatology registry.

RESULTS

Twelve pediatric COPA syndrome patients (mean age of 6.5 years at first imaging exam; 6 females) were identified. Imaging exams available for review included 45 chest CT exams on 12 patients, 37 musculoskeletal exams on 4 patients, and 10 renal US exams on 5 patients. All 12 had abnormal chest CT exams, with findings including ground-glass opacities (12/12), cysts (8/12), septal thickening (9/12), nodules (8/12), fibrosis (7/12), crazy-paving (2/12), consolidation (1/12), hilar/mediastinal lymphadenopathy (11/12), and chest wall deformity (5/12). Nine had at least one follow-up chest CT, which showed improvement in nodules (7/9), ground-glass opacities (4/9), and lymphadenopathy (9/9), but worsening of septal thickening (3/9), cyst formation (3/9), and fibrosis (3/9). Four had musculoskeletal imaging revealing synovitis (2/4), bone erosions (1/4), tenosynovitis (1/4), enthesitis (1/4), and subcutaneous nodules (1/4). Five had at least one renal US, revealing renal size abnormalities (4/5) and cortical hyperechogenicity (3/5).

CONCLUSION

The most prevalent imaging finding of COPA syndrome is diffuse lung disease related to early childhood-onset recurrent pulmonary hemorrhage and lymphoid hyperplasia that may progress to pulmonary fibrosis. Other imaging findings manifesting later in childhood or adolescence relate to arthritis and glomerulonephritis.

Late pulmonary complications related to cancer treatment in children

As the number of childhood cancer survivors increases, a heightened awareness and recognition of therapy-related late effects is becoming more important. Pulmonary complications are the third leading cause of late mortality in cancer survivors. Diagnosis of these complications on chest imaging helps facilitate prompt treatment to mitigate adverse outcomes. In this review, we summarize the imaging of late pulmonary complications of cancer therapy in children and highlight characteristic findings that should be recognized by radiologists.

Computed tomography evaluation of pediatric pulmonary hypertension

Although rare in the pediatric population, pulmonary hypertension is a significant cause of morbidity and mortality in affected individuals. In addition to evaluating potential causes and severity of parenchymal lung diseases, non-contrast high-resolution CT of the chest can aid in the diagnosis of heritable and acquired causes. In addition to evaluating parenchymal lung disease, CT angiography can help to confirm findings of pulmonary hypertension using criteria similar to echocardiography, and provide detailed assessment of the pulmonary vascularity in specific causes.

Lower skeletal muscle mass on CT body composition analysis is associated with adverse clinical course and outcome in children with COVID-19

OBJECTIVES

To assess the association between body composition measures in children with COVID-19 and severity of the disease course and clinical outcome.

METHODS

A retrospective study of children (< 19 years) with COVID-19 admitted to the hospital who underwent CT of the chest and/or abdomen was conducted. Data compiled from electronic medical records included demographics, body mass index (BMI), length of stay, ICU admission, invasive mechanical ventilation and death. Waist circumference and perimeters for skeletal muscle mass (abdominal, psoas and paraspinal muscles) were measured on an axial CT image at the level of the twelfth thoracic vertebra or first lumbar vertebra using FIJI software.

RESULTS

Fifty-seven subjects were identified (54% male, median age 15.6 years, 61% Hispanic, 23% African-American). 25% (14/57) were admitted to the ICU and 21% (12/57) needed intubation. 9% (5/57) died. Waist circumference ranged between 53.2 and 138.4 cm (mean 86.58 ± 18.74 cm) and skeletal muscle mass ranged between 0.6 and 6.8 cm2 (mean 3.5 ± 1.19 cm2). Lower skeletal muscle mass had a univariate association with ICU admission (odds ratio (OR) 0.4; 95%CI 0.17-0.76; p = 0.01) and mortality (OR 0.22; 95%CI 0.04-0.69; p = 0.01). Multivariate analysis showed similar association after controlling for comorbidities (adjusted OR 0.46; 95%CI 0.19-0.95; p = 0.04 and adjusted OR 0.31; 95%CI 0.06-0.95; p = 0.04, respectively). There was no association between BMI or waist circumference with ICU stay, mechanical ventilation or mortality.

CONCLUSION

Lower skeletal muscle mass is associated with an adverse clinical course and outcome in children with COVID-19.

CT imaging of esophageal foreign bodies in children: a pictorial essay

Foreign body (FB) ingestion is common in children, particularly from 6 months to 3 years of age. As young children may be unable to provide a clinical history and the ingestion is often unwitnessed, imaging plays an important role in diagnosis, predicting outcomes and detecting complications that require surgical intervention. Since 2015, our institution's diagnostic algorithm for suspected airway foreign bodies has included a noncontrast airway FB CT (FB-CT) with the z-axis coverage spanning from the larynx to the proximal segmental bronchi of the lower lung zones. The effective dose of radiation from this FB-CT airway protocol is typically less than 1 mSv, compared to an effective dose of just under 1 mSv to up to 3 mSv for a fluoroscopic esophagram in children under 10 years of age and 1-3 mSv for a routine pediatric CT chest. In using the FB-CT airway protocol at our institution, we observed that esophageal rather than airway FBs were sometimes encountered on these exams. However, the confidence among radiologists for definitively diagnosing an esophageal foreign body on noncontrast CT was variable. Consequently, we created a teaching module of positive cases for our group of 21 pediatric body radiologists to increase their diagnostic confidence. This pictorial essay illustrates our institutional experience and can help others to confidently diagnose esophageal foreign bodies using a dedicated CT foreign body imaging protocol. At a similar radiation dose to a fluoroscopic esophagram, CT provides the additional advantage of an expedited diagnosis without the need for a radiologist on site.

Role of anticoagulation in the management of tumor thrombus: A 10-year single-center experience

BACKGROUND

Children with cancer diagnosis are overall at a higher risk of thrombosis. For a newly diagnosed blood clot, patients are commonly started on anticoagulants to prevent further extension and embolization of the clot. In the rare instance that a pediatric patient has a tumor thrombus, role of anticoagulation is less clear.

PROCEDURE/METHODS

Patients under 21 years of age with a finding of tumor thrombus on imaging from 2010 to 2020 at Texas Children's Hospital were identified and their medical records were reviewed.

RESULTS

A total of 50 patients were identified. Most thrombi were incidental findings at diagnosis; however, two patients presented with pulmonary embolism (PE). Inferior vena cava extension was noted in 36% of the patients, and 24% patients had an intracardiac tumor thrombus. Anticoagulation was initiated in 10 patients (20%). There was no difference in the rate of bland thrombus formation and/or embolization in patients who did or did not receive anticoagulation. However, three of the six patients with asymptomatic tumor thrombus who were started on anticoagulation had bleeding complications compared to only two patients in the no anticoagulation cohort (p < .05).

CONCLUSION

Children with intravascular extension of solid tumors were not commonly started on anticoagulation at the time of diagnosis, irrespective of the extent of tumor thrombus. Furthermore, we observed a significant trend toward higher incidence of bleeding complications after initiation of anticoagulation for asymptomatic tumor thrombus. There is inadequate evidence at this time to support routine initiation of anticoagulation in pediatric patients with intravascular extension of solid tumors.

Pulmonary manifestations and outcomes in paediatric ANCA-associated vasculitis: a single-centre experience

OBJECTIVES

ANCA-associated vasculitis (AAV) usually involves the renal and respiratory systems, but the paediatric literature on pulmonary manifestations and outcomes is limited. We aimed to describe pulmonary manifestations and outcomes after therapy in a cohort of paediatric AAV (pAAV) patients.

METHODS

A retrospective chart review of all patients <19 years presenting to our institution with AAV between 1/2008 and 2/2018 was conducted. Patient demographics, clinical presentation, diagnostic testing, therapy and pulmonary outcomes over the first 3 years after presentation were evaluated.

RESULTS

A total of 38 patients were included; all had ANCA positivity by immunofluorescence. A total of 23 had microscopic polyangiitis (MPA), 13 had granulomatosis with polyangiitis and 2 had eosinophilic granulomatosis with polyangiitis. A total of 30 (79%) had pulmonary manifestations, with cough (73%) and pulmonary haemorrhage (67%) being the most common. Abnormalities were noted in 82% of chest CT scans reviewed, with nodules and ground-glass opacities being the most common. At 6, 12 and 36 months follow-up, respectively, 61.8%, 39.4% and 29% of patients continued to show pulmonary manifestations. Five MPA patients with re-haemorrhage are described in detail.

CONCLUSION

MPA was more common than granulomatosis with polyangiitis, with pulmonary involvement being common in both. MPA patients had more severe pulmonary manifestations. Chest CT revealed abnormal findings in a majority of cases. A subgroup of young MPA patients experienced repeat pulmonary haemorrhage. Treatment modality and response were comparable in different subtypes of AAV, except for this young MPA group. Additional prospective studies are needed to better understand the different phenotypes of pAAV.

Ten rules for ordering chest CTs

These "rules" are suggestions for clinicians who order chest computed tomography (CTs). The first three address CT scanning technique and the ordering details that we find cause the most confusion. The next three are on patient preparation, and specifically the use of sedation and anesthesia. Radiation risk is next, and we end with three, more philosophical, rules on how we can best work together as clinicians and imagers. This is not a complete or systematic review. You won't find detailed references (or any references for that matter), descriptions of the latest techniques, or lists of sample protocols. We hope that the reader will consult his or her imaging colleagues when more specific guidance is needed. The goal of this article is to provide simple answers to frequently asked questions and to address some of the concerns that arise when deciding how to perform a chest CT scan in a child. These are the opinions of the authors, two pediatric radiologists with special interest in chest imaging and 50 years combined experience in working with clinical colleagues to provide the best imaging care for their patients. We hope that sharing these thoughts will help to decrease confusion and increase understanding to the benefit of the children we serve.

Pulmonary Histopathology Findings in Patients With STAT3 Gain of Function Syndrome

INTRODUCTION AND AIM

Multiorgan autoimmunity and interstitial lung disease (ILD) are reported in patients with STAT3 GOF syndrome.

RESULTS

We present lung histopathology findings in 3 such children, two of whom underwent wedge biopsies with adequate diagnostic material. Wedge biopsies showed interstitial cellular expansion with linear and nodular aggregates of CD8 positive T lymphocytes, plasma cells, and histiocytes; consistent with lymphocytic interstitial pneumonia pattern (LIP). CD4+ T cells and CD20+ B cells were present but infrequent in the interstitium. FOXP3 cells ranged from 0-5%. Focal interstitial and intraalveolar histiocytes were also seen. Neutrophils and eosinophils were rare/absent. Non-occlusive peribronchial lymphoid aggregates showed equal T and B cells; likely reactive in nature. Pulmonary vessels appeared normal without vasculitis or hypertensive change. There was no interstitial or subepithelial fibrosis or organizing pneumonia. Interlobular septa and visceral pleura were unremarkable.

CONCLUSION

Children with multi-system autoimmune disorders with ILD should be investigated for STAT3 GOF syndrome. Lung wedge biopsies are more informative than transbronchial biopsies, if a tissue sampling is indicated. CD8 dominant T cell inflammation seems to be a key driver of ILD. Although interstitial fibrosis was not seen in our small sample, longer follow up is needed to understand the natural history.

Untwisting the complexity of midgut malrotation and volvulus ultrasound

Abdominal US is emerging as an alternative to the upper gastrointestinal (GI) series as the preferred diagnostic imaging test for midgut malrotation complicated by volvulus. Unlike the upper GI series, US is free from ionizing radiation, does not require oral contrast agent, and can be performed portably and at times remotely from the interpreting radiologist, expediting diagnosis. Although some institutions do not have a standardized US protocol for midgut volvulus, many routinely use US in the setting of an infant or child with acute abdominal signs or symptoms to evaluate for common conditions such as hypertrophic pyloric stenosis, intussusception, necrotizing enterocolitis and appendicitis. Because these common conditions can overlap in age and clinical presentation with midgut volvulus, the aim of this pictorial essay is to provide instruction on the technique and diagnostic findings of midgut volvulus on US to ensure confident, accurate interpretation, and prompt treatment.

Chest CT for the Diagnosis of Pediatric Esophageal Foreign Bodies

Foreign body ingestion is a common problem in children. Radiography is the mainstay of imaging, but many radiolucent items go undetected without further imaging by fluoroscopic esophagram. While studies in adults support the use of computed tomography (CT) for esophageal foreign body ingestion, CT has historically not been used in children given the typically higher radiation doses on CT compared with fluoroscopy. In distinction to an esophagram, CT does not require oral contrast nor presence of an onsite radiologist and can be interpreted remotely. At our institution, a dedicated CT protocol has been used for airway foreign bodies since 2015. Given the advantages of CT over esophagram, we retrospectively reviewed institutional radiation dose data from 2017 to 2020 for esophagrams, airway foreign body CT (FB-CT), and routine CT Chest to compare effective doses for each modality. For ages 1+ years, effective dose was lowest using the FB-CT protocol; esophagram mean dose showed the most variability, and was over double the dose of FB-CT for ages 5+ years. Routine CT chest doses were uniformly highest across all age ranges. Given these findings, we instituted a CT foreign body imaging protocol as the first-line imaging modality for radiolucent esophageal foreign body at our institution.

Diagnostic sensitivity and specificity of CT angiography for renal artery stenosis in children

BACKGROUND

Children with suspected renal artery stenosis (RAS) are screened with renal Doppler ultrasonography or computed tomography (CT) angiography/magnetic resonance (MR) angiography depending on institutional preference. CT angiography produces images with superior resolution, allowing higher quality multiplanar two-dimensional reformats and three-dimensional reconstructions. However, there is a paucity of data in the literature regarding the utility and diagnostic performance of renal CT angiography in pediatric RAS.

OBJECTIVE

The objective of this study is to retrospectively review our experience with renal CT angiography in the diagnosis of pediatric RAS relative to digital subtraction angiography (DSA) as the reference standard.

MATERIALS AND METHODS

All patients 0-18 years of age who underwent CT angiography for evaluation of RAS as a cause of hypertension between January 2012 and May 2019 were identified for the study. A total of 131 patients were identified, 23 of whom had DSA correlation.

RESULTS

Twenty-three patients (17 boys, 6 girls) with a mean age of 6 years 3 months (range: 3 months to 14 years 7 months) were included in this study. Of the 59 renal arteries studied by DSA, 22 were abnormal on CT angiography and 20 were abnormal on DSA. Of the 59 renal arteries, CT angiography was true positive in 18 and true negative in 35. The sensitivity and specificity of CT angiography for RAS diagnosis were 90.0% and 89.7%, respectively. CT angiography identified all cases of main RAS.

CONCLUSION

Renal CT angiography has a high sensitivity and specificity for pediatric RAS diagnosis in patients referred for DSA.

A Novel Large-Vessel Arteritis in SARS-CoV-2-Related Multisystem Inflammatory Syndrome in Children (MIS-C)

Multisystem inflammatory syndrome in children (MIS-C) is a newly defined condition associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The syndrome has been described as a "Kawasaki disease"-like illness and the spectrum of associated abnormalities, including vascular complications, remain to be fully defined. The novel findings of a large-vessel arteritis in this report will add to the understanding of this syndrome and its associated vascular complications.

Management of severe pulmonary Langerhans cell histiocytosis in children

Patients with pulmonary Langerhans cell histiocytosis (LCH) typically have a benign course but may have extensive cystic lung disease with rare life-threatening complications including multiple and recurrent pneumothoraces and respiratory failure. We report seven severely affected pediatric patients treated with chemotherapy, aggressive chest tube management, and pleurodesis of whom five survived. Patients with extraordinary amounts of pulmonary cystic disease and multiple pneumothoraces due to LCH can have remarkable, curative outcomes with early recognition, optimal LCH-directed therapy, and supportive care.

Pediatric thoracic mass lesions: Beyond the common

Thoracic mass lesions can be categorized as originating in one of the three major compartments: a) chest wall and pleura, b) lung parenchyma and airways, c) mediastinum. While some of these, such as lymphoma, are common in both children and adults, others are rare and unique to childhood. The goal of this review is to familiarize radiologists with unusual but distinctive mass lesions of the pediatric thorax.

Emergent high fatality lung disease in systemic juvenile arthritis

OBJECTIVE

To investigate the characteristics and risk factors of a novel parenchymal lung disease (LD), increasingly detected in systemic juvenile idiopathic arthritis (sJIA).

METHODS

In a multicentre retrospective study, 61 cases were investigated using physician-reported clinical information and centralised analyses of radiological, pathological and genetic data.

RESULTS

LD was associated with distinctive features, including acute erythematous clubbing and a high frequency of anaphylactic reactions to the interleukin (IL)-6 inhibitor, tocilizumab. Serum ferritin elevation and/or significant lymphopaenia preceded LD detection. The most prevalent chest CT pattern was septal thickening, involving the periphery of multiple lobes ± ground-glass opacities. The predominant pathology (23 of 36) was pulmonary alveolar proteinosis and/or endogenous lipoid pneumonia (PAP/ELP), with atypical features including regional involvement and concomitant vascular changes. Apparent severe delayed drug hypersensitivity occurred in some cases. The 5-year survival was 42%. Whole exome sequencing (20 of 61) did not identify a novel monogenic defect or likely causal PAP-related or macrophage activation syndrome (MAS)-related mutations. Trisomy 21 and young sJIA onset increased LD risk. Exposure to IL-1 and IL-6 inhibitors (46 of 61) was associated with multiple LD features. By several indicators, severity of sJIA was comparable in drug-exposed subjects and published sJIA cohorts. MAS at sJIA onset was increased in the drug-exposed, but was not associated with LD features.

CONCLUSIONS

A rare, life-threatening lung disease in sJIA is defined by a constellation of unusual clinical characteristics. The pathology, a PAP/ELP variant, suggests macrophage dysfunction. Inhibitor exposure may promote LD, independent of sJIA severity, in a small subset of treated patients. Treatment/prevention strategies are needed.

Imaging of DICER1 syndrome

DICER1 syndrome is a highly pleiotropic tumor predisposition syndrome that has been increasingly recognized in the last 10 years. Diseases in the syndrome result from mutations in both copies of the gene DICER1, a highly conserved gene that is critically implicated in micro-ribonucleic acid (miRNA) biogenesis and hence modulation of messenger RNAs. In general, susceptible individuals carry an inherited germline mutation that disables one copy of DICER1; within tumors, a very characteristic second mutation alters function of the other gene copy. About 20 hamartomatous, hyperplastic or neoplastic conditions comprise DICER1 syndrome. Most are not life-threatening, but some are aggressive malignancies. There are many unaffected carriers because penetrance is generally low; however, clinically occult thyroid nodules and lung cysts are frequent. Rare diseases of early childhood were the first recognized conditions in DICER1 syndrome, while other conditions affect adolescents and adults. The hallmarks of DICER1 syndrome are certain rare tumors including pleuropulmonary blastoma; cystic nephroma; ovarian Sertoli-Leydig cell tumor; sarcomas of the cervix, kidneys and cerebrum; pituitary blastoma; ciliary body medulloepithelioma; and nasal chondromesenchymal hamartoma. Radiologists are often the first practitioners to observe these diverse manifestations and play a primary role in recognizing DICER1 syndrome.

A novel approach using volumetric dynamic airway computed tomography to determine positive end-expiratory pressure (PEEP) settings to maintain airway patency in ventilated infants with bronchopulmonary dysplasia

BACKGROUND

Positive end-expiratory pressure (PEEP) is a key mechanical ventilator setting in infants with bronchopulmonary dysplasia (BPD). Excessive PEEP can result in insufficient carbon dioxide elimination and lung damage, while insufficient PEEP can result in impaired gas exchange secondary to airway and alveolar collapse. Determining PEEP settings based on clinical parameters alone is challenging and variable.

OBJECTIVE

The purpose of this study was to describe our experience using dynamic airway CT to determine the lowest PEEP setting sufficient to maintain expiratory central airway patency of at least 50% of the inspiratory cross-sectional area in children with BPD requiring long-term ventilator support.

MATERIALS AND METHODS

We retrospectively identified all infants with BPD who underwent volumetric CT with a dynamic airway protocol for PEEP optimization from December 2014 through April 2019. Sixteen infants with BPD underwent 17 CT exams. Each CT exam consisted of acquisitions spanning the trachea and mainstem bronchi. We measured cross-sectional area of the trachea and mainstem bronchi and qualitatively assessed the amount of atelectasis. We documented changes in management as a result of the CT exam.

RESULTS

The average effective dose was 0.1-0.8 mSv/scan. Of 17 CT exams, PEEP was increased in 9, decreased in 3 and unchanged after 5 exams.

CONCLUSION

Dynamic airway CT shows promise to assist the clinician in determining PEEP settings to maintain airway patency in infants with BPD requiring long-term ventilator support. Further evaluation of the impact of this maneuver on gas exchange, cardiac output and other physiological measures is needed.

Treatment-Responsive Granulomatous-Lymphocytic Interstitial Lung Disease in a Pediatric Case of Common Variable Immunodeficiency

Granulomatous-Lymphocytic Interstitial Lung disease (GLILD) is a granulomatous and lymphoproliferative condition occurring in ~25% of Common Variable Immunodeficiency (CVID) patients with the highest prevalence in the late teen to young adult years. GLILD was first described in adults and carries a poor prognosis with survival estimated to be reduced by half. Here we report a pediatric case of CVID-associated GLILD that presented with rapid deterioration over 3 months and responded to adult-based treatment with dual chemotherapeutic agents (rituximab and azathioprine), resulting in complete resolution of clinical findings and near complete resolution of radiologic findings. This case highlights the opportunity to achieve a favorable outcome in GLILD following appropriate diagnosis and therapy.

Unfounded conclusions of equivalence in diagnostic accuracy studies: a pervasive fallacy of inference in pediatric radiology scientific abstracts

BACKGROUND

In studies of diagnostic performance that fail to detect a statistically significant difference between compared techniques, investigators often declare evidence of equivalence or similarity without having actually tested that assertion due to incorrect methodology or insufficient statistical power.

OBJECTIVE

The purpose of our investigation is to measure the prevalence of unfounded assertions of equivalence or similarity in comparison studies presented at the International Pediatric Radiology (IPR) meeting of 2016 and promote awareness of this fallacy of inference to the pediatric radiology community.

MATERIALS AND METHODS

Two pediatric radiologists independently reviewed the methodology and reporting quality of the 194 scientific paper abstracts from the 2016 IPR meeting. All comparison studies were identified and those failing to detect a statistically significance difference and making a claim of equivalence or similarity in the results or conclusion were assessed for a description of the study design type, statistical power and sample size estimator calculation.

RESULTS

Of 194 scientific paper abstracts, 112 (58%) were comparison studies. Of these, 36/112 (32%) made unfounded inferences of equivalence or similarity in diagnostic imaging performance. No study had an equivalence or non-inferiority design. No abstract specified the statistical power of the study, and only one abstract acknowledged a small sample size as a limitation in detecting a statistically significant difference.

CONCLUSION

Inadequate reporting and unfounded inferences of equivalence or similarity were common in diagnostic performance comparison studies presented at IPR 2016. Failure to recognize these limitations could have adverse consequences by leading to the adoption of unvalidated imaging techniques.

Correction to: Comparative safety and efficacy of balloon use in air enema reduction for pediatric intussusception

The original version on this paper contained an error. The names of M. John Hicks and R. Paul Guillerman, though correctly appeared in the published version, are incorrectly displayed in indexing sites.

Diagnostic Performance of Ultrasonography for Pediatric Appendicitis: A Night and Day Difference?

RATIONALE AND OBJECTIVES

For imaging pediatric appendicitis, ultrasonography (US) is preferred because of its lack of ionizing radiation, but is limited by operator dependence. This study investigates the US diagnostic performance during night shifts covered by radiology trainees compared to day shifts covered by attending radiologists.

MATERIALS AND METHODS

Appy-Scores (1 = completely visualized normal appendix; 2 = partially visualized normal appendix; 3 = nonvisualized appendix with no inflammatory changes in the expected region of the appendix; 4 = equivocal; 5a = nonperforated appendicitis; 5b = perforated appendicitis) from 2935 US examinations (2161:774, day-to-night) from July 2013 to 2014 were correlated with the intraoperative diagnoses and the clinical follow-up. The diagnostic performance of trainees and attendings was compared with Fisher exact test. Interobserver agreement was measured by Cohen kappa coefficient.

RESULTS

Appendicitis prevalence was 25.3% (day) and 22.5% (night). Sensitivity, specificity, accuracy, negative predictive value, and positive predictive vale were 94.0%, 93.7%, 93.8%, 97.9%, and 83.4% during the day and 92.0%, 91.2%, 91.3%, 97.5%, and 75.2% at night. Specificity (P = .048) and positive predictive value (P = .011) differed, with more false positives at night (7%) than during the day (4.7%). Trainee and attending agreement was high (k = 0.995), with Appy-Scores of 1, 4, and 5a most frequently discordant.

CONCLUSIONS

US has a high diagnostic performance and interobserver agreement for pediatric appendicitis when interpreted by radiology trainees during night shifts or attending radiologists during day shifts. However, lower specificity and positive predictive value at night warrants a thorough trainee education to avoid false-positive examinations.

Lung Transplantation for FLNA-Associated Progressive Lung Disease

OBJECTIVE

To describe a series of patients with pathogenic variants in FLNA and progressive lung disease necessitating lung transplantation.

STUDY DESIGN

We conducted a retrospective chart review of 6 female infants with heterozygous presumed loss-of-function pathogenic variants in FLNA whose initial presentation was early and progressive respiratory failure.

RESULTS

Each patient received lung transplantation at an average age of 11 months (range, 5-15 months). All patients had pulmonary arterial hypertension and chronic respiratory failure requiring tracheostomy and escalating levels of ventilator support before transplantation. All 6 patients survived initial lung transplantation; however, 1 patient died after a subsequent heart-lung transplant. The remaining 5 patients are living unrestricted lives on chronic immunosuppression at most recent follow-up (range, 19 months to 11.3 years post-transplantation). However, in all patients, severe ascending aortic dilation has been observed with aortic regurgitation.

CONCLUSIONS

Respiratory failure secondary to progressive obstructive lung disease during infancy may be the presenting phenotype of FLNA-associated periventricular nodular heterotopia. We describe a cohort of patients with progressive respiratory failure related to a pathogenic variant in FLNA and present lung transplantation as a viable therapeutic option for this group of patients.

The optimal timing of surgical resection in high-risk neuroblastoma

BACKGROUND

While most high-risk neuroblastoma (HRNB) patients are enrolled in cooperative group or institutional protocols, variability exists within these protocols as to when surgical resection of the primary tumor should be performed after neoadjuvant induction chemotherapy. We sought to determine if the number of chemotherapy cycles prior to surgery affects surgical or survival outcomes in HRNB patients.

METHODS

We performed a retrospective review of all HRNB patients <18years of age from 2000 to 2010, at Texas Children's Hospital. Patients were stratified based on the number of neoadjuvant induction chemotherapy cycles prior to surgical resection. Pre and post- chemotherapy tumor size, MYCN status, iodine-131-metaiodobenzylguanidine (MIBG) score at diagnosis, extent of surgical resection, estimated surgical blood loss, post-operative outcomes, and event free (EFS) and overall survival (OS) were evaluated. Data were analyzed using Wilcoxon rank-sum test, Kruskal-Wallis test, Fisher's exact test, Kaplan-Meier analyses, and Cox regression analyses. P-value <0.05 was considered significant.

RESULTS

Data from 50 patients with HRNB were analyzed. Patients were stratified by the number of cycles of chemotherapy received prior to surgery. Six patients received 2cycles of chemotherapy (12%), 20 patients received 3cycles (40%), 13 patients received 4cycles (26%), and 11 patients received 5cycles (22%) prior to surgical resection of the primary tumor. The 5-year OS was 33%, 45%, 83% and 36% in patients who received 2, 3, 4 and 5cycles of chemotherapy prior to surgery, respectively (p=0.07). Multivariate analysis revealed that patients who received 4cycles of chemotherapy had a significantly lower mortality (HR: 0.11, 95% CI: 0.01-0.87, p=0.04) compared to those with 2cycles of chemotherapy. Among the different cohorts, there were no differences with respect to MYCN status, MIBG score at diagnosis, incidence of bone marrow metastasis, extent of surgical resection, estimated blood loss, incidence of post-operative complications, or length of stay.

CONCLUSION

HRNB patients who receive 4cycles of chemotherapy prior to surgical resection have a superior OS than patients who receive 2. Based on the superior survival of patients who received 4cycles of chemotherapy prior to surgery, further studies are warranted to elucidate these differences.

Copa Syndrome: a Novel Autosomal Dominant Immune Dysregulatory Disease

Inherently defective immunity typically results in either ineffective host defense, immune regulation, or both. As a category of primary immunodeficiency diseases, those that impair immune regulation can lead to autoimmunity and/or autoinflammation. In this review we focus on one of the most recently discovered primary immunodeficiencies that leads to immune dysregulation: "Copa syndrome". Copa syndrome is named for the gene mutated in the disease, which encodes the alpha subunit of the coatomer complex-I that, in aggregate, is devoted to transiting molecular cargo from the Golgi complex to the endoplasmic reticulum (ER). Copa syndrome is autosomal dominant with variable expressivity and results from mutations affecting a narrow amino acid stretch in the COPA gene-encoding COPα protein. Patients with these mutations typically develop arthritis and interstitial lung disease with pulmonary hemorrhage representing a striking feature. Immunologically Copa syndrome is associated with autoantibody development, increased Th17 cells and pro-inflammatory cytokine expression including IL-1β and IL-6. Insights have also been gained into the underlying mechanism of Copa syndrome, which include excessive ER stress owing to the impaired return of proteins from the Golgi, and presumably resulting aberrant cellular autophagy. As such it represents a novel cellular disorder of intracellular trafficking associated with a specific clinical presentation and phenotype.

Clinical Practice Guidelines From the Cystic Fibrosis Foundation for Preschoolers With Cystic Fibrosis

Cystic fibrosis (CF) clinical care guidelines exist for the care of infants up to age 2 years and for individuals ≥6 years of age. An important gap exists for preschool children between the ages of 2 and 5 years. This period marks a time of growth and development that is critical to achieve optimal nutritional status and maintain lung health. Given that disease often progresses in a clinically silent manner, objective and sensitive tools that detect and track early disease are important in this age group. Several challenges exist that may impede the delivery of care for these children, including adherence to therapies. A multidisciplinary committee was convened by the CF Foundation to develop comprehensive evidence-based and consensus recommendations for the care of preschool children, ages 2 to 5 years, with CF. This document includes recommendations in the following areas: routine surveillance for pulmonary disease, therapeutics, and nutritional and gastrointestinal care.

Does Routine Imaging of Patients for Progression or Relapse Improve Survival in Rhabdomyosarcoma?

BACKGROUND

Patients with rhabdomyosarcoma (RMS) who complete therapy typically undergo 4 years of surveillance imaging despite lack of evidence that this improves outcomes. We compared overall survival (OS) between patients in whom progression or relapse was detected by routine clinical evaluation or by imaging.

PROCEDURE

Children with progressive or relapsed RMS treated at Texas Children's Hospital between 1992 and 2012 were identified and their records were reviewed. Survival time after progression or relapse was compared between two groups: (1) patients in whom progression or relapse was suspected on the basis of clinical history, symptoms, laboratory evaluation, or physical exam; and (2) patients whose progression or relapse was initially detected by imaging.

RESULTS

Of the 43 children with progressive or relapsed RMS, 26 (60%) had metastatic disease at diagnosis and 19 (44%) had alveolar histology. With a median follow up time of 5 years in six survivors, there was no difference in OS between patients in whom progression or relapse was diagnosed based on imaging (n = 15) or by clinical evaluation (n = 28) (3-year OS 20% vs. 11%, respectively, P = 0.38). Disease extent, primary site, and risk group at diagnosis were associated with survival after progression or relapse.

CONCLUSIONS

Routine surveillance imaging practice should be critically reviewed for children with RMS. Although our findings must be validated by larger studies, they do have substantive implications. Reduced imaging tailored to the risk and pattern of recurrence, associated risks and cost could improve patient quality of life and decrease health-care expenditure without compromising outcome.

Mucoepidermoid Carcinoma in Children: A Single Institutional Experience

PURPOSE AND OBJECTIVE

To determine the clinicopathologic and molecular features and outcome of children with mucoepidermoid carcinoma (MEC).

METHODS

A retrospective analysis of clinical and histopathologic findings was performed in patients with MEC diagnosed at Texas Children's Cancer Center between 2000 and 2014.

RESULTS

Ten female and four male patients with median age 12 years (range 7-19 years) were included in the study. Tumors involved major salivary glands, minor salivary glands of the palate, and the tracheobronchial tree. Nine of 11 patients with salivary MEC underwent more than one surgical resection at the time of initial diagnosis to achieve a gross total resection. Three patients with tracheobronchial tumors underwent pulmonary lobectomy. Three patients received postoperative radiation therapy. No patient was treated with chemotherapy. Histopathologic grades were classified as low (n = 2), intermediate (n = 9), and high (n = 3). All 12 patients with tumor tissue available for testing were positive for MECT1/MAML2 fusion transcripts. There were no deaths, metastases, or recurrences in this series, with a median follow-up of 24 months (range 5-96 months).

CONCLUSIONS

Low to intermediate histopathologic grade MECs are more common than high grade MEC in children. In contrast to adults, MECT1/MAML2 fusion transcripts occur with a frequency of 100% in our pediatric MEC series. Complete excision is the treatment of choice and is associated with excellent outcome. The role of radiotherapy is unclear, but may be indicated in patients with high grade tumors with positive surgical margins.

International Pediatric Non-Hodgkin Lymphoma Response Criteria

PURPOSE

Response criteria are well established for adult patients with non-Hodgkin lymphoma (NHL). A revised set of response criteria in adults with NHL was recently published. However, NHL in children and adolescents involves different histologies, primary sites of disease, patterns of metastatic spread, approaches to therapy, and responses to treatment compared with adult NHL. However, there are no standardized response criteria specific to pediatric NHL. Therefore, we developed international standardized methods for assessing response to therapy in children and adolescents with NHL.

METHODS

An international multidisciplinary group of pediatric oncologists, pathologists, biologists, and radiologists convened during and after the Third and Fourth International Childhood, Adolescent and Young Adult NHL Symposia to review existing response and outcome data, develop methods for response evaluation that reflect incorporation of more sensitive technologies currently in use, and incorporate primary and metastatic sites of disease for the evaluation of therapeutic response in children and adolescents with NHL.

RESULTS

Using the current adult NHL response criteria as a starting point, international pediatric NHL response criteria were developed incorporating both contemporary diagnostic imaging and pathology techniques, including novel molecular and flow cytometric technologies used for the determination of minimal residual disease.

CONCLUSION

Use of the international pediatric NHL response criteria in children and adolescents receiving therapy for NHL incorporates data obtained from new and more sensitive technologies that are now being widely used for disease evaluation, providing a standardized means for reporting treatment response.

Revised International Pediatric Non-Hodgkin Lymphoma Staging System

PURPOSE

Treatment and prognosis of pediatric non-Hodgkin lymphoma (NHL) have improved dramatically in the last 30 years. However, the St Jude NHL staging classification for pediatric NHL was developed more than 35 years ago. The most recent Lugano lymphoma staging classification focused on adult lymphoma. Furthermore, major limitations of the current pediatric NHL staging classification include lack of consideration of new distinct pediatric NHL histologic entities; absence of recognition of frequent skin, bone, kidney, ovarian, and other organ involvement; and lack of newer precise methods to detect bone marrow and CNS involvement, minimal disease quantification, and highly sensitive imaging technologies.

METHODS

An international multidisciplinary expert panel convened in Frankfurt, Germany, in 2009 at the Third International Childhood, Adolescent and Young Adult NHL Symposium to develop a revised international pediatric NHL staging system (IPNHLSS), addressing limitations of the current pediatric NHL staging system and creating a revised classification. Evidence-based disease distribution and behavior were reviewed from multiple pediatric cooperative group NHL studies.

RESULTS

A revised IPNHLSS was developed incorporating new histologic entities, extranodal dissemination, improved diagnostic methods, and advanced imaging technology.

CONCLUSION

This revised IPNHLSS will facilitate more precise staging for children and adolescents with NHL and facilitate comparisons of efficacy across different treatment strategies, various institutions, multicenter trials, and cooperative groups by allowing for reproducible pediatric-based staging at diagnosis and relapse.

The incidental pulmonary nodule in a child. Part 2: Commentary and suggestions for clinical management, risk communication and prevention

The incidental detection of small lung nodules in children is a vexing consequence of an increased reliance on CT. We present an algorithm for the management of lung nodules detected on CT in children, based on the presence or absence of symptoms, the presence or absence of elements in the clinical history that might explain these nodules, and the imaging characteristics of the nodules (such as attenuation measurements within the nodule). We provide suggestions on how to perform a thoughtfully directed and focused search for clinically occult extrathoracic disease processes (including malignant disease) that may present as an incidentally detected lung nodule on CT. This algorithm emphasizes that because of the lack of definitive information on the natural history of small solid nodules that are truly detected incidentally, their clinical management is highly dependent on the caregivers' individual risk tolerance. In addition, we present strategies to reduce the prevalence of these incidental findings, by preventing unnecessary chest CT scans or inadvertent inclusion of portions of the lungs in scans of adjacent body parts. Application of these guidelines provides pediatric radiologists with an important opportunity to practice patient-centered and evidence-based medicine.

Ifosfamide and vinorelbine is an effective reinduction regimen in children with refractory/relapsed Hodgkin lymphoma, AHOD00P1: a children's oncology group report

BACKGROUND

We assessed the safety and efficacy of ifosfamide and vinorelbine (IV) as a less toxic and effective reinduction regimen for pediatric patients with relapsed or refractory Hodgkin Lymphoma.

PROCEDURE

This multi-center Children's Oncology Group phase II pilot study enrolled patients <30 years of age with biopsy-proven Hodgkin Lymphoma in relapse or refractory disease after front-line therapy. Treatment consisted of ifosfamide 3,000 mg/m(2) intravenous infusion over 24 hr on Days 1-4 and vinorelbine 25 mg/m(2) /dose intravenous push on Days 1 and 5 of each 21 day cycle with cytokine support. The study endpoints included estimation of key toxicities (cardiac, hepatic, or renal toxicity or toxic death), the rate of successful peripheral stem cell harvesting, and response after two cycles of therapy.

RESULTS

Sixty-six patients received a median of two cycles of IV. Sixty-four of 66 were heavily pretreated, 4 had refractory disease, 55% were male and 79% had nodular sclerosis HL. The primary toxicities were hematologic. Harvested peripheral stem cells were sufficient for autologous transplantation in 46 of 54 patients for whom stem cell collection was attempted. The overall response rate (72%; 95% CI 59-83%) permitted the majority of patients to undergo subsequent stem cell transplantation.

CONCLUSIONS

IV is a safe and effective re-induction regimen for salvage of pediatric patients with relapsed or refractory Hodgkin Lymphoma with an excellent response rate and success of post chemotherapy stem cell harvest. It avoids the use of etoposide, an agent associated with secondary malignancy after stem cell transplantation.

Relapse surveillance in AFP-positive hepatoblastoma: re-evaluating the role of imaging

BACKGROUND

Children with hepatoblastoma routinely undergo repetitive surveillance imaging, with CT scans for several years after therapy, increasing the risk of radiation-induced cancer.

OBJECTIVE

The purpose of this study was to determine the utility of surveillance CT scans compared to serum alpha-fetoprotein (AFP) levels for the detection of hepatoblastoma relapse.

MATERIALS AND METHODS

This was a retrospective study of all children diagnosed with AFP-positive hepatoblastoma from 2001 to 2011 at a single institution.

RESULTS

Twenty-six children with hepatoblastoma were identified, with a mean age at diagnosis of 2 years 4 months (range 3 months to 11 years). Mean AFP level at diagnosis was 132,732 ng/ml (range 172.8-572,613 ng/ml). Five of the 26 children had hepatoblastoma relapse. A total of 105 imaging exams were performed following completion of therapy; 88 (84%) CT, 8 (8%) MRI, 5 (5%) US and 4 (4%) FDG PET/CT exams. A total of 288 alpha-fetoprotein levels were drawn, with a mean of 11 per child. The AFP level was elevated in all recurrences and no relapses were detected by imaging before AFP elevation. Two false-positive AFP levels and 15 false-positive imaging exams were detected. AFP elevation was found to be significantly more specific than PET/CT and CT imaging at detecting relapse.

CONCLUSION

We recommend using serial serum AFP levels as the preferred method of surveillance in children with AFP-positive hepatoblastoma, reserving imaging for the early postoperative period, for children at high risk of relapse, and for determination of the anatomical site of clinically suspected recurrence. Given the small size of this preliminary study, validation in a larger patient population is warranted.

Exploring the association Between DICER1 mutations and differentiated thyroid carcinoma

CONTEXT

Carriers of germline DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 syndrome. Thyroid abnormalities are a common finding in DICER1 syndrome with multinodular goiter frequently present in many families in which a germline DICER1 mutation is segregating. Differentiated thyroid carcinoma (DTC) is infrequently seen in such pedigrees. In addition to germline DICER1 mutations, specific somatic mutations have been identified in the DICER1 ribonuclease IIIb catalytic domain in several tumor types.

OBJECTIVE

We aimed to determine whether such characteristic somatic DICER1 mutations are present in DTCs that arise within germline DICER1 mutation carriers.

DESIGN AND SETTING

The study involved an opportunistic collection of 3 cases of DTC arising in individuals suspected to have DICER1 syndrome and hospital-based ascertainment and testing was implemented.

RESULTS

We identified somatic DICER1 mutations in 3 DTCs arising in unrelated germline DICER1 mutation carriers, all of whom had been diagnosed in infancy with pleuropulmonary blastoma (PPB), were treated with chemotherapy, exposed frequently to diagnostic radiation, and subsequently developed DTC. The somatic mutations occurred within the DICER1 ribonuclease IIIb domain, affecting highly conserved amino acid residues central to the catalytic activity of the domain.

CONCLUSION

This report of somatic DICER1 mutations in DTC strengthens the association between DTC and the DICER1 syndrome. The possible association between germline DICER1 mutations, PPB treatment, and the risk of subsequent DTC must be considered by clinicians when treating PPB.

Pediatric Burkitt's lymphoma and diffuse B-cell lymphoma: are surveillance scans required?

Outcomes in pediatric B-Non-Hodgkin Lymphoma (B NHL) have improved with intensive chemotherapy protocols, with long-term survival now over 80%. However, long-term adverse effects of therapy and poor outcomes for patients who relapse remain challenges. In this study, we aimed to evaluate the potential risks and benefits of routine relapse surveillance imaging after the completion of therapy. We reviewed 44 B NHL patients diagnosed and treated at Texas Children's Cancer Center in the period between 2000 to 2011. All cross-sectional diagnostic imaging examinations performed for disease assessment after completion of chemotherapy were reviewed and cumulative radiation dosage from these examinations and the frequency of relapse detection by these examinations were recorded. Only 3 patients of the 44 relapsed (6.8%), though none of the relapses were initially diagnosed by computed tomography (CT) or fludeoxyglucose positron emission tomography (FDG-PET) scans. Median effective dose of ionizing radiation per patient was 40.3 mSv with an average of 49.1 mSv (range 0-276 mSv). This single-institution study highlights the low relapse rate in pediatric B-NHL with complete response at the end of therapy, the low sensitivity of early detection of relapse with surveillance CT or FDG-PET imaging, and the costs and potential increased risk of secondary malignancies from cumulative radiation exposure from surveillance imaging. We propose that routine surveillance CT or FDG-PET scans for these patients may not be necessary.