Paediatric and adolescent Hodgkin lymphoma: information derived from diffuse organ uptake of 18 F-fluorodeoxyglucose on pre-treatment and on interim PET/CT.

PURPOSE: To evaluate, in children with Hodgkin lymphoma (HL), the frequency and intensity of visually diffuse FDG uptake by selected organs at baseline (bPET) and on interim PET/CT (iPET), and to evaluate the relation between FDG uptake, metabolic response and evolution of the disease with treatment. PATIENTS AND METHODS: Thirty children with HL had bPET and then iPET after two cycles of treatment, which were blind-read retrospectively. Excluding sites with focal uptake, diffuse FDG uptake by thymus, bone marrow at iliac crests, liver, spleen, and the spinal cord at the 12th thoracic vertebra (Th12) was evaluated visually using a three-point scoring method and semiquantitatively by measuring SUVmax. Visualisation of activated brown adipose tissue (BAT) was also quoted. Five children had refractory HL. Recurrence-free survival was determined for each patient. Nine patients relapsed; in 21 non-relapsing patients, the median follow-up period was 43 months (range: 28-61). RESULTS: On bPET, the rate of diffuse and intense (visual score = 3) FDG uptake was 48 % in the spleen, 43 % in the spinal cord at Th12, 37 % in bone marrow, 21 % in the thymus and 7 % in BAT. At least one of those sites showed diffuse and intense FDG uptake in 77 % of patients. On iPET, a significant decrease in SUVmax was observed in thymus, iliac crest bone marrow and spleen, but not in spinal cord. In contrast, the FDG uptake by the liver significantly increased. The absence of SUVmax increase in the liver between bPET and iPET was the best criterion to predict a refractory disease (PPV = 55 %, NPV = 100 %). Its area under ROC (AUC) was 0.9 vs. 0.73 for five-point Deauville criteria. For prediction of relapse, two criteria were derived from the evolution of diffuse uptake between bPET and iPET: no increase in liver uptake and an increase > 5 % in spinal cord uptake. As compared with 13 patients who matched none of those criteria, the hazard ratio (HR) for relapse was 2.1 in 13 patients who matched one criterion, and 10.3 in four patients who matched both (Kaplan-Meier analysis p = 0.005). CONCLUSION: Diffuse and intense FDG uptake by organs is frequent in children with HL on bPET. On iPET, it is frequently reduced in all sites except the liver, which may pose problems for visual quotation of the FDG intensity of HL foci. The variation of SUVmax between bPET and iPET permitted us to achieve a prediction of refractory or relapsing HL that was at least as effective as using criteria based on FDG uptake by the HL lesions. The results of this retrospective pilot study need further validation.

Clinical predictors of radiographic abnormalities among infants with bronchiolitis in a paediatric emergency department.

BACKGROUND: Acute viral respiratory exacerbation is one of the most common conditions encountered in a paediatric emergency department (PED) during winter months. We aimed at defining clinical predictors of chest radiography prescription and radiographic abnormalities, among infants with bronchiolitis in a paediatric emergency department. METHODS: We conducted a prospective cohort study of children less than 2 years of age with clinical bronchiolitis, who presented for evaluation at the paediatric emergency department of an urban general hospital in France. Detailed information regarding historical features, examination findings, and management were collected. Clinical predictors of interest were explored in multivariate logistic regression models. RESULTS: Among 410 chest radiographs blindly interpreted by two experts, 40 (9.7%) were considered as abnormal. Clinical predictors of chest radiography achievement were age (under three months), feeding difficulties, fever over 38°C, hypoxia under than 95% of oxygen saturation, respiratory distress, crackles, and bronchitis rales. Clinical predictors of radiographic abnormalities were fever and close to significance hypoxia and conjunctivitis. CONCLUSION: Our study provides arguments for reducing chest radiographs in infants with bronchiolitis. For infants with clinical factors such as age less than three months, feeding difficulties, respiratory distress without hypoxia, isolated crackles or bronchitis rales, careful clinical follow-up should be provided instead of chest radiography.

Originality of new imaging techniques in pediatric radiology.

Pediatric radiology is a specialty that combines the performances of imaging and radio-protection. It also has to deal with absence of cooperation and motion of the child which have limited for a long time many radiological applications. Technical advances with shorter acquisition time in CT and MRI, higher frequencies in ultrasound, and digitalization in conventional radiology have widened the indications especially with the new modalities. We present in this article the originalities and the benefits of current pediatric radiology and perform a historic review outlining its evolution.

Proximal tibial epiphyseal intraosseous schwannoma: a rare entity.

Schwannoma is a benign nerve sheath tumor most commonly located in the soft tissue. Occasionally, schwannomas involve osseous structures. The rarity of osseous involvement leads to omission of schwannoma from the initial differential diagnosis in the majority of cases. Intraosseous schwannomas arising in children have not been reported. We present the case of a schwannoma affecting the proximal tibial epiphysis in a growing child. Intraosseous schwannomas should be included in the differential diagnosis of lytic epiphyseal benign-appearing bone lesions in children. Its radiographic characteristics mimic those of benign chondroblastoma.

[Exposure to CT scans in childhood and long-term cancer risk: A review of epidemiological studies]. / Exposition à la scanographie dans l'enfance et risque de cancer à long terme. Une synthèse des études épidémiologiques récentes.

Amongst medical exams requiring ionizing radiation, computed tomography (CT) scans are used more frequently, including in children. These CT examinations are associated with absorbed doses that are much higher than those associated with conventional radiology. In comparison to adults, children have a greater sensitivity to radiation and a longer life span with more years at cancer risks. Five epidemiological studies on cancer risks after CT scan exposure during childhood were published between 2012 and 2015. The results of these studies are consistent and show an increase of cancer risks in children who have been exposed to several CT scans. However, methodological limits due to indication bias, retrospective assessment of radiation exposure from CT scans and lack of statistical power are to be taken into consideration. International projects such as EPI-CT (Epidemiological study to quantify risks for pediatric computerized tomography and to optimize dose), with a focus on dosimetric reconstruction and minimization of bias will provide more precise results. In the meantime, available results reinforce the necessity of justification and optimization of doses.

Impact of chest radiography for children with lower respiratory tract infection: a propensity score approach.

BACKGROUND: Management of acute respiratory tract infection varies substantially despite this being a condition frequently encountered in pediatric emergency departments. Previous studies have suggested that the use of antibiotics was higher when chest radiography was performed. However none of these analyses had considered the inherent indication bias of observational studies. OBJECTIVE: The aim of this work was to assess the relationship between performing chest radiography and prescribing antibiotics using a propensity score analysis to address the indication bias due to non-random radiography assignment. METHODS: We conducted a prospective study of 697 children younger than 2 years of age who presented during the winter months of 2006-2007 for suspicion of respiratory tract infection at the Pediatric Emergency Department of an urban general hospital in France (Paris suburb). We first determined the individual propensity score (probability of having a chest radiography according to baseline characteristics). Then we assessed the relation between radiography and antibiotic prescription using two methods: adjustment and matching on the propensity score. RESULTS: We found that performing a chest radiography lead to more frequent antibiotic prescription that may be expressed as OR = 2.3, CI [1.3-4.1], or as an increased use of antibiotics of 18.6% [0.08-0.29] in the group undergoing chest radiography. CONCLUSION: Chest radiography has a significant impact on the management of infants admitted for suspicion of respiratory tract infection in a pediatric emergency department and may lead to unnecessary administration of antibiotics.

Specificity of paediatric jawbone lesions: tumours and pseudotumours.

INTRODUCTION: Characteristics and epidemiology of jaw tumours have been described mostly in adults. Compared with their adult counterparts, childhood jaw tumours show considerable differences. The aim of this study was to describe the different jaw tumours in children, define diagnostic tools to determine their specificity and describe optimal treatment. METHODS: All children patients with jaw lesions, excluding cysts, apical granuloma and osteitis were included in our study between 1999 and 2009. The medical records were analyzed for clinical, radiological, and pathological findings, treatments and recurrences. RESULTS: Mean patient age was 10.9 years old, ranging from 2 months to 18 years old. Of the 63 lesions, 18 were odontogenic and 45 non-odontogenic lesions. 6% of all cases were malignant tumours; the mean age of presentation was 7.25 years old, [ranging from 0.2 to 18 years old]. Approximately 80% of the tumours developed after 6 years of age. Odontogenic tumours occurred more often after the age of 6. CONCLUSION: Compared with their adult counterpart, childhood jaw tumours show considerable differences in their clinical behaviour and radiological and pathological characteristics. Clinical features of some tumours can be specific to children. Tumourigenesis is related to dental development and facial growth. Conservative treatment should be considered.