Introduction to the COG Diagnostic Imaging Committee/SPR Oncology Committee White Papers: Rationale and methods.

Pediatric cancer is a rare disease. Because of this, many sites do not have experience providing imaging for specific tumor types. The Children's Oncology Group Diagnostic Imaging Committee and the Society for Pediatric Radiology Oncology Committee are comprised of radiologists with expertise in pediatric cancer imaging. Recently, this group endeavored to create a series of 23 White Papers designed to provide evidence-based imaging recommendations and minimum achievable imaging protocols. The purpose of this manuscript is to describe the methods employed in authoring the White Paper series.

Pilot study to determine whether reduced-dose photon-counting detector chest computed tomography can reliably display Brody II score imaging findings for children with cystic fibrosis at radiation doses that approximate radiographs.

BACKGROUND: The Brody II score uses chest CT to guide therapeutic changes in children with cystic fibrosis; however, patients and providers are often reticent to undergo chest CT given concerns about radiation. OBJECTIVE: We sought to determine the ability of a reduced-dose photon-counting detector (PCD) chest CT protocol to reproducibly display pulmonary disease severity using the Brody II score for children with cystic fibrosis (CF) scanned at radiation doses similar to those of a chest radiograph. MATERIALS AND METHODS: Pediatric patients with CF underwent non-contrast reduced-dose chest PCD-CT. Volumetric inspiratory and expiratory scans were obtained without sedation or anesthesia. Three pediatric radiologists with Certificates of Added Qualification scored each scan on an ordinal scale and assigned a Brody II score to grade bronchiectasis, peribronchial thickening, parenchymal opacity, air trapping and mucus plugging. We report image-quality metrics using descriptive statistics. To calculate inter-rater agreement for Brody II scoring, we used the Krippendorff alpha and intraclass correlation coefficient (ICC). RESULTS: Fifteen children with CF underwent reduced-dose PCD chest CT in both inspiration and expiration (mean age 8.9 years, range, 2.5-17.5 years; 4 girls). Mean volumetric CT dose index (CTDIvol) was 0.07 ± 0.03 mGy per scan. Mean effective dose was 0.12 ± 0.04 mSv for the total examination. All three readers graded spatial resolution and noise as interpretable on lung windows. The average Brody II score was 12.5 (range 4-19), with moderate inter-reader reliability (ICC of 0.61 [95% CI=0.27, 0.84]). Inter-rater reliability was moderate to substantial for bronchiectasis (0.52), peribronchial thickening (0.55), presence of opacity (0.62) and air trapping (0.70) and poor for mucus plugging (0.09). CONCLUSION: Reduced-dose PCD-CT permits diagnostic image quality and reproducible identification of Brody II scoring imaging findings at radiation doses similar to those for chest radiography.

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

Primary pancreatic tumors in children are rare with an overall age-adjusted incidence of 0.018 new cases per 100,000 pediatric patients. The most prevalent histologic type is the solid pseudopapillary neoplasm, followed by pancreatoblastoma. This paper describes relevant imaging modalities and presents consensus-based recommendations for imaging at diagnosis and follow-up.

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.

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

Primary hepatic malignancies are relatively rare in the pediatric population, accounting for approximately 1%-2% of all pediatric tumors. Hepatoblastoma and hepatocellular carcinoma are the most common primary liver malignancies in children under the age of 5 years and over the age of 10 years, respectively. This paper provides consensus-based imaging recommendations for evaluation of patients with primary hepatic malignancies at diagnosis and follow-up during and after therapy.

Imaging of pre- and post-cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pediatric intraperitoneal malignancy.

Although rare, pediatric peritoneal carcinomatosis does occur in primary abdominopelvic tumors. Additionally, peritoneal carcinomatosis has been described to occur as metastatic disease where the primary tumor is outside the abdominopelvic cavity. Where amenable, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) can be beneficial in disease management. However, favorable outcomes are predicated on specific tumor histology as well as proper patient selection, which significantly relies on preoperative imaging. This review gives a comprehensive, up-to-date summary on pediatric peritoneal carcinomatosis pre-surgical evaluation; where imaging is beneficial and limited; pediatric radiologists' role in helping to quantify disease; and how we, as pediatric radiologists, can help the surgeons and oncologists in the selection of patients for cytoreductive surgery and HIPEC.

Meckel diverticulum in the pediatric population: Patient presentation and performance of imaging in prospective diagnosis.

PURPOSE: To determine the most common presentations of Meckel diverticulum (MD) in children and the performance of imaging modalities in prospective diagnosis. MATERIALS AND METHODS: A 28-year retrospective review was performed of children under 18 years of age with MD listed as a diagnosis on pathology and/or surgical reports. The medical record was reviewed to determine presenting clinical scenarios. All imaging performed for each case was reviewed. RESULTS: Seventy-six patients met inclusion criteria. Of the surgically removed MD, most presented with abdominal symptoms (n = 31, 41%); gastrointestinal (GI) bleeding (n = 15, 20%), or both abdominal symptoms and GI bleeding (n = 7, 9%). Twenty-nine percent of MD were discovered incidentally at surgery performed for other reasons. Of the symptomatic MD, only 31% were prospectively diagnosed. For patients with abdominal symptoms, CT had a sensitivity of 13% (3/24) while nuclear medicine (NM) scan had a sensitivity of 0% (0/2). For patients with GI bleed, CT had a sensitivity of 29% (2/7) and NM scan had a sensitivity of 71% (10/14). For patients with both abdominal symptoms and GI bleed, CT was 0% (0/2) and NM scan 75% (3/4) sensitive. CONCLUSION: MD as a cause of abdominal symptoms and gastrointestinal bleeding may be difficult to diagnose due to nonspecific presentations and nonspecific findings. Most prospectively diagnosed MD are on NM scan in patients with GI bleed with abdominal pain (sensitivity of >70%). CT is relatively insensitive for MD in all symptomatology groups (0 to 29%).

NUT carcinoma of the thorax in a 7-year-old child.

We present a rare case of NUT midline carcinoma of the thorax in a 7-year-old-male who presented with nonspecific abdominal pain. The patient was initially evaluated with an abdominal ultrasound, which was negative, followed by an abdominopelvic CT that demonstrated a partially visualized infiltrative mediastinal mass. Subsequent, chest CT showed a large, aggressive appearing heterogenous middle mediastinal mass with pulmonary parenchyma, hilar, and posterior mediastinal invasion. Given its epicenter in the middle mediastinum and its irregular and invasive appearance, the primary consideration was NUT midline carcinoma, subsequently confirmed on biopsy.

Chylolymphatic mesenteric cyst with midgut volvulus in an adolescent: a peculiar presentation.

Mesenteric cysts are rare intra-abdominal masses in the pediatric population, with the chylolymphatic variant comprising only 7.3% of all abdominal cysts. These cysts can have a varied clinical presentation, ranging from asymptomatic cystic masses to intestinal obstruction. We report a 16-year-old female, who presented with acute abdominal pain and vomiting, and was diagnosed with an intra-abdominal cystic mass with midgut volvulus accompanied by the classical "whirlpool sign" on imaging. She underwent laparoscopic abdominal exploration, which revealed a large chylolymphatic mesenteric cyst associated with feeder lymph vessels. This cyst had resulted in volvulus of the small bowel. The bowel was detorsed and found to be viable, and the cyst was removed en bloc after suction evacuation with ligation of the lymphatic feeder vessels. Midgut volvulus in the pediatric population is usually secondary to malrotation, but in this case the patient's small intestine was not found to be malrotated, and hence we present this case and urge physicians to consider a diagnosis of midgut volvulus even in the absence of malrotation in a child with a cystic abdominal mass presenting as intestinal obstruction.

Magnetic resonance imaging of the pediatric mediastinum: updates, tips and tricks.

Magnetic resonance imaging (MRI) of the pediatric mediastinum is challenging for the practicing radiologist. Many confounding factors add to the complexity of pediatric mediastinal MRI including small patient size, broad spectrum of mediastinal pathologies, motion artifacts and the need for sedation in a significant portion of children. However, with special attention to motion-reduction techniques and knowledge of pediatric-specific considerations, pediatric radiologists can help to provide accurate and timely diagnosis and also prevent multimodality imaging where MRI might be all that is needed. The purpose of this paper was present a practical review of pediatric mediastinal MRI with particular emphasis on diseases where MRI is the primary imaging modality of choice. Additionally, the author addresses those mediastinal processes for which MRI serves as a secondary problem-solving imaging tool.

Corrigendum to 'Anaplastic ependymoma metastases through a ventriculoperitoneal shunt' [Radiology Case Reports 15 (2020) 650-654].

[This corrects the article DOI: 10.1016/j.radcr.2020.02.036.].

MRI diagnosis of rubber band constriction syndrome.

Rubber band syndrome is caused by constriction of the wrist from elastic bracelets worn for decorative purposes. Overtime, the fixed or elastic band burrows into the skin and becomes invisible. We present the case of a 2.5-year-old female child presenting to our institution with signs of circumferential swelling and inflammatory changes about the right wrist. MRI of the wrist demonstrated a subcutaneous circular foreign body, which was confirmed at surgery to be a rubber band. Although this disease entity is rare, radiologists can be instrumental in suggesting this diagnosis based on the location involved, ie, wrist, and the imaging findings.

Anaplastic ependymoma metastases though a ventriculoperitoneal shunt.

Ependymomas are rare glial tumors that comprise 10% of intracranial pediatric malignancies. Primary central nervous system malignancies can rarely metastasize extracranially. When metastases occur, it usually does so in the setting of surgical manipulation of the central nervous system and can spread through the blood, lymph, or artificial means, for example, a ventriculoperitoneal shunt. We describe the presentation and progression of an 18-month-old boy diagnosed with an ependymoma. Initially managed with surgery, radiation, and ventriculoperitoneal shunt placement for symptomatic hydrocephalus, the tumor later recurred with drop metastasis to the thoracic spinal cord. The patient subsequently developed extensive metastases within the abdominal cavity, which were seeded through a ventriculoperitoneal shunt. We present a case of a rare complication of intra-abdominal tumor seeding and carcinomatosis from an intracranial ependymoma through a ventriculoperitoneal shunt. This is a rare presentation of a possible complication, which requires awareness of both surgeons and radiologists.

Subperiosteal hemorrhage: A rare complication in neurofibromatosis which may mimic malignant peripheral nerve sheath tumor.

Currently, there is little in the medical literature on subperiosteal hematomas in neurofibromatosis patients, particularly in those who have subperiosteal neurofibromas. Initial imaging and clinical presentation can be very worrisome and to the unaware may lead to early surgical intervention and/or anxiety in the patient and parents. This report presents the case of a 9-year-old child with neurofibromatosis type-1 and progressively increasing calf pain and swelling about a known plexiform neurofibroma. Imaging at initial presentation and at 1 month demonstrated evolving subperiosteal hemorrhage. This report adds to the small body of literature on subperiosteal hemorrhage as a complication of neurofibromatosis. Additionally, this report demonstrates an approach to noninvasive management of these lesions with the utility of initial and 1 month follow-up radiographs helpful in demonstrating hemorrhage evolution and possibly negating the need for biopsy.