Solid pseudopapillary neoplasms of the pancreas in childhood and adolescence-an analysis of the German Registry for Rare Pediatric Tumors (STEP).

Solid pseudopapillary neoplasms (SPNs) are the most common entity among pediatric pancreatic tumors. Still, these are rare tumors with an annual incidence of 0.1-0.2/1,000,000, and little is known about their optimal treatment. This analysis aimed to increase knowledge about the occurrence and treatment strategies of SPN in childhood. Data regarding diagnostics, treatment, and outcome of children aged 0-18 years with SPN recorded in the German Registry for Rare Pediatric Tumors (STEP) were analyzed. Thirty-eight patients were identified with a median age of 14.5 years at diagnosis (range: 8-18) and a female preponderance (81.6%). The most frequent location of the tumor was the pancreatic tail. In histopathological and immunohistochemical examination, pseudopapillary, solid, and cystic lesions as well as expression of beta-catenin, progesterone receptors, and cyclin D1 were the most common findings. All patients underwent surgical resection. Most patients underwent open resection, predominantly tail resection for tumors in the tail region and pylorus-preserving pancreaticoduodenectomy for tumors in the head region. The main postoperative sequela was exogenous pancreatic insufficiency (23.7%), especially with SPN in the pancreatic head. No recurrence occurred during follow-up, although two patients underwent resection with microscopic residue. CONCLUSION: SPN of the pancreas in childhood are low-grade malignancies with usually favorable treatment outcomes. However, therapy can lead to relevant long-term sequelae. To prevent recurrence, complete surgical resection is recommended, sparing as much healthy pancreatic tissue as possible. Interdisciplinary collaboration between specialists is essential to optimize treatment. Molecular genetic analysis of these tumors could improve understanding of their genesis. WHAT IS KNOWN: • Solid pseudopapillary neoplasms (SPNs) of the pancreas are very rare tumors in childhood. • Little is known about tumorigenesis, and there are no specific guidelines for treatment and follow-up in pediatric patients. WHAT IS NEW: • Characteristics, treatment, and outcome were comprehensively assessed in a large cohort of pediatric patients with SPN. • We propose recommendations for diagnosis, treatment, and follow-up of children with SPN, based on our analysis and considering published experience.

Balloon angioplasty versus stent placement for the treatment of portal vein stenosis in children: a single center experience.

PURPOSE: To evaluate the safety and efficacy of percutaneous interventional treatment of portal vein stenosis in children. MATERIAL AND METHODS: A retrospective analysis of all interventional treatments for portal vein stenosis in pediatric patients at a single institution from 2010 to 2021 was conducted. Platelet count, spleen size and portal vein flow velocity were assessed during the follow-up period. Primary and primary assisted patency time were determined. RESULTS: A total of ten children (median age 28.5 months, interquartile range (IQR): 2.75-52.5 months) with portal vein stenosis after Mesorex-Shunt (n = 4), liver transplantation (n = 3) and other etiologies (n = 3) underwent 15 interventional procedures. There were five reinterventions and one discontinued intervention. The technical success rate was 93.3% (14/15) and clinical success of treated patients was 100% (14/14). Median follow-up was 18 months (IQR: 13.5-81 months). The median primary patency time for stent placement was 70 months (IQR: 13.5-127.25 months). For balloon angioplasty, the median primary patency time was 9 months (IQR 7.25-11.5 months), while the median assisted primary patency time was 14 months (IQR: 12 to 15 months). Platelet count, spleen size and portal vein flow velocity reliably corresponded to recurrence of portal vein stenosis in asymptomatic patients during follow-up. CONCLUSION: Interventional treatment is a safe and efficient method to treat portal vein stenosis with long patency times, regardless of etiology. Primary stent placement shows a higher primary patency time than balloon angioplasty. Implementation of stent placement as the primary interventional method may improve patency times and reduce the need for repeat reinterventions in pediatric patients.

Evaluation of functional and metabolic tumor volume using voxel-wise analysis in childhood rhabdomyosarcoma.

BACKGROUND: Cross-sectional imaging-based morphological characteristics of pediatric rhabdomyosarcoma have failed to predict outcomes. OBJECTIVE: To evaluate the feasibility and possible value of generating tumor sub-volumes using voxel-wise analysis of metabolic and functional data from positron emission tomography/magnetic resonance imaging (PET/MR) or PET/computed tomography (CT) and MRI in rhabdomyosarcoma. MATERIALS AND METHODS: Thirty-four examinations in 17 patients who received PET/MRI or PET/CT plus MRI were analyzed. The volume of interest included total tumor volume before and after therapy. Apparent diffusion coefficients (ADC) and standard uptake values (SUV) were determined voxel-wise. Voxels were assigned to three different groups based on ADC and SUV: "viable tumor tissue," "intermediate tissue" or "possible necrosis." In a second approach, data were grouped into three clusters using the Gaussian mixture model. The ratio of these clusters to total tumor volume and changes due to chemotherapy were correlated with clinical and histopathological data. RESULTS: After chemotherapy, the proportion of voxels in the different groups changed significantly. A significant reduction of the proportion of voxels assigned to cluster 1 was found, from a mean of 36.4% to 2.5% (P < 0.001). There was a significant increase in the proportion of voxels in cluster 3 following chemotherapy from 24.8% to 81.6% (P = 0.02). The proportion of voxels in cluster 2 differed depending on the presence or absence of tumor recurrence, falling from 48% to 10% post-chemotherapy in the group with no tumor recurrence (P < 0.05) and from 29% to 23% (P > 0.05) in the group with tumor recurrence. CONCLUSION: Voxel-wise evaluation of multimodal data in rhabdomyosarcoma is feasible. Our initial results suggest that the different distribution of sub-volumes before and after therapy may have prognostic significance.

MRI Characteristics of Pediatric Renal Tumors: A SIOP-RTSG Radiology Panel Delphi Study.

BACKGROUND: The SIOP-Renal Tumor Study Group (RTSG) does not advocate invasive procedures to determine histology before the start of therapy. This may induce misdiagnosis-based treatment initiation, but only for a relatively small percentage of approximately 10% of non-Wilms tumors (non-WTs). MRI could be useful for reducing misdiagnosis, but there is no global consensus on differentiating characteristics. PURPOSE: To identify MRI characteristics that may be used for discrimination of newly diagnosed pediatric renal tumors. STUDY TYPE: Consensus process using a Delphi method. POPULATION: Not applicable. FIELD STRENGTH/SEQUENCE: Abdominal MRI including T1- and T2-weighted imaging, contrast-enhanced MRI, and diffusion-weighted imaging at 1.5 or 3 T. ASSESSMENT: Twenty-three radiologists from the SIOP-RTSG radiology panel with ≥5 years of experience in MRI of pediatric renal tumors and/or who had assessed ≥50 MRI scans of pediatric renal tumors in the past 5 years identified potentially discriminatory characteristics in the first questionnaire. These characteristics were scored in the subsequent second round, consisting of 5-point Likert scales, ranking- and multiple choice questions. STATISTICAL TESTS: The cut-off value for consensus and agreement among the majority was ≥75% and ≥60%, respectively, with a median of ≥4 on the Likert scale. RESULTS: Consensus on specific characteristics mainly concerned the discrimination between WTs and non-WTs, and WTs and nephrogenic rest(s) (NR)/nephroblastomatosis. The presence of bilateral lesions (75.0%) and NR/nephroblastomatosis (65.0%) were MRI characteristics indicated as specific for the diagnosis of a WT, and 91.3% of the participants agreed that MRI is useful to distinguish NR/nephroblastomatosis from WT. Furthermore, all participants agreed that age influenced their prediction in the discrimination of pediatric renal tumors. DATA CONCLUSION: Although the discrimination of pediatric renal tumors based on MRI remains challenging, this study identified some specific characteristics for tumor subtypes, based on the shared opinion of experts. These results may guide future validation studies and innovative efforts. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 3.

Whole liver transplantation in children under 10 kg: How to minimize the high risks of a still challenging procedure.

BACKGROUND: Whole liver transplantation in infants <10 kg is a rare procedure with moderate outcomes (67%-79% graft survival at 1 year) and high rates of vascular complications (hepatic artery thrombosis 5-26%). METHODS: Retrospective single-center analysis of whole liver transplantation in infants <10 kg and systematic review of the literature focused on survival rates and surgical complications. RESULTS: Between January 2005 and December 2020, 175 liver transplantations in 173 children were performed at our center. A total of 92 (53%) children weighed less than 10 kg; 19 (21%) of them underwent WLT and constitute the study population. Median age of the recipients was 10 months (21 days-24 months) and median body weight 6.5 (3.1-9.8) kg. Median age of the donors was 5 (1-84) months and median body weight 6.1 (4-21) kg. Median donor-to-recipient body weight ratio was 1.2 (range: 0.6-4.5). Postoperatively, neither hepatic artery nor portal vein thrombosis occurred. A biliary complication occurred in 4 cases: 1 bile leak (early), 3 anastomotic stenoses (1 delayed and 2 late), and 1 non-anastomotic stenosis (late). Patient survival rate at 1, 5, and 10 years was 100%, 92%, and 92%, respectively. Overall, death-censored graft survival after 1, 5, and 10 was 100%. CONCLUSION: Our results are excellent in terms of complications and graft and patient survival. This involves not only high-end surgical performance but also close interdisciplinary perioperative cooperation based on strong standard operating procedures and mainly focused on fluid management, hemostasiology, and strict monitoring of vessel patency.

[Recurrent Pulmonary Hemorrhages with Hemoptysis as a Result of Vocal Cord Dysfunction (VCD) - An Attempt to Explain]. / Rezidivierende pulmonale Hämorrhagien mit Hämoptoe als Folge einer Vocal Cord Dysfunction (VCD) ­ ein Erklärungsversuch.

We present the case of an otherwise healthy 19-year-old student who has been affected by vocal cord dysfuntion (VCD) since she is fourteen. 3 years after that diagnosis she has also been coughing blood at an increasing rate (1-3 times per week). We postulate that the haemoptoe is the result of breathing against a closed airway which can lead to excessively high negative intrathoracic pressures. Which, in turn, rapture alveolar capillaries. After bilateral injection of Botulinum toxin injection into the muscles vocalis, VCD as well as haemoptoe episodes ceased for three months.

European guideline for imaging in paediatric and adolescent rhabdomyosarcoma - joint statement by the European Paediatric Soft Tissue Sarcoma Study Group, the Cooperative Weichteilsarkom Studiengruppe and the Oncology Task Force of the European Society of Paediatric Radiology.

Appropriate imaging is essential in the treatment of children and adolescents with rhabdomyosarcoma. For adequate stratification and optimal individualised local treatment utilising surgery and radiotherapy, high-quality imaging is crucial. The paediatric radiologist, therefore, is an essential member of the multi-disciplinary team providing clinical care and research. This manuscript presents the European rhabdomyosarcoma imaging guideline, based on the recently developed guideline of the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG) Imaging Committee. This guideline was developed in collaboration between the EpSSG Imaging Committee, the Cooperative Weichteilsarkom Studiengruppe (CWS) Imaging Group, and the Oncology Task Force of the European Society of Paediatric Radiology (ESPR). MRI is recommended, at diagnosis and follow-up, for the evaluation of the primary tumour and its relationship to surrounding tissues, including assessment of neurovascular structures and loco-regional lymphadenopathy. Chest CT along with [F-18]2-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET)/CT or PET/MRI are recommended for the detection and evaluation of loco-regional and distant metastatic disease. Guidance on the estimation of treatment response, optimal long-term follow-up, technical imaging settings and standardised reporting are described. This European imaging guideline outlines the recommendations for imaging in children and adolescents with rhabdomyosarcoma, with the aim to harmonise imaging and to advance patient care.

[Radiological imaging of neuroblastoma]. / Radiologische Bildgebung des Neuroblastoms.

BACKGROUND: Neuroblastomas are tumors of the sympathetic nervous system that arise from the sympathetic trunk and adrenal glands. Tissue compositions, molecular genetics, and overall prognosis are heterogeneous. With an incidence of 1:6000, neuroblastomas account for 5.5% of childhood tumors. They usually occur in children up to preschool age with the mean age of 14 months. Adults are very rarely affected. Imaging, especially magnetic resonance imaging (MRI), plays an essential role in diagnosis, risk stratification, and therapy control. MATERIALS AND METHODS: Based on a selective literature search in the PubMed database, the national and international societies' guidelines and study protocols, the imaging standards and the latest developments are presented. CONCLUSION: Imaging plays a key role in neuroblastomas due to the heterogeneous prognosis and the resulting very different therapy. A high degree of standardization in implementation and interpretation is important in every phase of the disease process. Sonography, MRI with diffusion weighting, and 123I­mIBG-SPECT are essential modalities. The extent of the diffusion restriction for assessing the degree of maturity and assessing the therapeutic response is becoming increasingly important in clinical routine. Up to now, PET imaging has mostly been complementary. Newly developed PET tracers promise comprehensive diagnostics and may also play a major role in theranostics.

Therapy Response Assessment of Pediatric Tumors with Whole-Body Diffusion-weighted MRI and FDG PET/MRI.

Background Whole-body diffusion-weighted (DW) MRI can help detect cancer with high sensitivity. However, the assessment of therapy response often requires information about tumor metabolism, which is measured with fluorine 18 fluorodeoxyglucose (FDG) PET. Purpose To compare tumor therapy response with whole-body DW MRI and FDG PET/MRI in children and young adults. Materials and Methods In this prospective, nonrandomized multicenter study, 56 children and young adults (31 male and 25 female participants; mean age, 15 years ± 4 [standard deviation]; age range, 6-22 years) with lymphoma or sarcoma underwent 112 simultaneous whole-body DW MRI and FDG PET/MRI between June 2015 and December 2018 before and after induction chemotherapy (ClinicalTrials.gov identifier: NCT01542879). The authors measured minimum tumor apparent diffusion coefficients (ADCs) and maximum standardized uptake value (SUV) of up to six target lesions and assessed therapy response after induction chemotherapy according to the Lugano classification or PET Response Criteria in Solid Tumors. The authors evaluated agreements between whole-body DW MRI- and FDG PET/MRI-based response classifications with Krippendorff α statistics. Differences in minimum ADC and maximum SUV between responders and nonresponders and comparison of timing for discordant and concordant response assessments after induction chemotherapy were evaluated with the Wilcoxon test. Results Good agreement existed between treatment response assessments after induction chemotherapy with whole-body DW MRI and FDG PET/MRI (α = 0.88). Clinical response prediction according to maximum SUV (area under the receiver operating characteristic curve = 100%; 95% confidence interval [CI]: 99%, 100%) and minimum ADC (area under the receiver operating characteristic curve = 98%; 95% CI: 94%, 100%) were similar (P = .37). Sensitivity and specificity were 96% (54 of 56 participants; 95% CI: 86%, 99%) and 100% (56 of 56 participants; 95% CI: 54%, 100%), respectively, for DW MRI and 100% (56 of 56 participants; 95% CI: 93%, 100%) and 100% (56 of 56 participants; 95% CI: 54%, 100%) for FDG PET/MRI. In eight of 56 patients who underwent imaging after induction chemotherapy in the early posttreatment phase, chemotherapy-induced changes in tumor metabolism preceded changes in proton diffusion (P = .002). Conclusion Whole-body diffusion-weighted MRI showed significant agreement with fluorine 18 fluorodeoxyglucose PET/MRI for treatment response assessment in children and young adults. © RSNA, 2020 Online supplemental material is available for this article.

Anomalous origin of the left coronary artery from the right aortic sinus: probably benign variant associated with a subpulmonic intramyocardial course - a case report.

BACKGROUND: Anomalous aortic origin of the left coronary artery (AAOLCA) from the right aortic sinus is a rare congenital anomaly associated with significantly increased risk of myocardial ischemia, arrhythmias and sudden cardiac death. This refers specifically to AAOLCA associated with interarterial and/or intramural course. Much less is known about anomalous origin of the left coronary artery from the right aortic sinus associated with a subpulmonic intramyocardial course. CASE PRESENTATION: We report a 12 year old girl who complained of recurrent episodes of chest pain lasting for some minutes and not associated to exercise. Echocardiography revealed AAOLCA from the right aortic sinus taking a subpulmonic course within the conal septum. The diagnosis was confirmed by CT-scan and selective coronary angiography. Treadmill test, Holter-ECG and bicycle-stress echocardiography revealed no evidence of myocardial ischemia reflecting unimpaired diastolic flow in the left coronary artery. According to the nature of the complaints and in the absence of signs of myocardial ischemia the episodes of chest pain were classified as idiopathic and not associated to the coronary anomaly. We opted for a conservative approach with regular follow-up visits. During a follow-up of 2 years without restriction of sports activities the patient has been asymptomatic. CONCLUSION: According to the literature AAOLCA with subpulmonary intramyocardial course appears to be associated with significantly less clinical problems than AAOLCA taking an interarterial course. The diagnosis can be suspected based on echocardiography and confirmed by contrast-enhanced computed tomography. Until now there are only few data concerning the natural history and incidence of complications in this specific anomaly. Despite the probably benign nature we recommend regular follow-up examinations including stress-testing in these patients.

Whole-body magnetic resonance imaging in pediatric oncology - recommendations by the Oncology Task Force of the ESPR.

The purpose of this recommendation of the Oncology Task Force of the European Society of Paediatric Radiology (ESPR) is to indicate reasonable applications of whole-body MRI in children with cancer and to address useful protocols to optimize workflow and diagnostic performance. Whole-body MRI as a radiation-free modality has been increasingly performed over the last two decades, and newer applications, as in screening of children with germ-line mutation cancer-related gene defects, are now widely accepted. We aim to provide a comprehensive outline of the diagnostic value for use in daily practice. Based on the results of our task force session in 2018 and the revision in 2019 during the ESPR meeting, we summarized our group's experiences in whole-body MRI. The lack of large evidence by clinical studies is challenging when focusing on a balanced view regarding the impact of whole-body MRI in pediatric oncology. Therefore, the final version of this recommendation was supported by the members of Oncology Task Force.

Comprehensive anatomical and functional imaging in patients with type I neurofibromatosis using simultaneous FDG-PET/MRI.

PURPOSE: To demonstrate the clinical use of FDG-PET/MRI for monitoring enlargement and metabolism of plexiform neurofibromas (PNF) in patients with neurofibromatosis type 1 (NF1), in whom the development of a malignant peripheral nerve sheath tumor (MPNST) is often a life limiting event. METHODS: NF1 patients who underwent a simultaneous FDG-PET/MRI examination in our institution from September 2012 to February 2018 were included. Indication was suspicion of malignant transformation of a PNF to MPNST. A maximum of six peripheral nerve lesions per patient were defined as targets. Standardized uptake values (SUV) and apparent diffusion coefficients (ADC) were measured. The presence of target sign and contrast-medium enhancement was visually recorded. Growth rates were estimated comparing prior or follow-up examinations and correlated with FDG uptake and ADC values. The presence of CNS lesions in cerebral T2 weighted images was recorded. RESULTS: In 28 NF1 patients a total number of 83 peripheral nerve tumors, 75 benign PNFs and eight MPNSTs, were selected as target lesions. The SUVs of MPNSTs were significantly higher than the SUVs of PNF (3.84 ± 3.98 [SUVmean MPNSTs] vs. 1.85 ± 1.03 [SUVmean PNF], P < .01). Similarly, lesion SUVmean-to-liver SUVmean ratios significantly differed between MPNSTs and PNF (3.20 ± 2.70 [MPNSTs] vs. 1.23 ± 0.61 [PNF]; P < .01). For differentiation between still benign PNF and MPNSTs, we defined SUVmax ≥ 2.78 as a significant cut-off value. Growth rate of PNF correlated significantly positively with SUVmean (rs = .41; P = .003). MRI parameters like ADCmean (1.87 ± 0.24 × 10-3 mm2/s [PNF] vs. 1.76 ± 0.11 × 10-3 mm2/s [MPNSTs]; P > .05], contrast medium enhancement (P = .50) and target sign (P = .86) did not differ between groups. CONCLUSION: Simultaneous FDG-PET/MRI is a comprehensive imaging modality for monitoring PNF in NF1 patients. The combined acquisition of both morphologic information in MRI and metabolic information in PET enables the correlation of lesion growth rates with metabolic activity and to define SUV thresholds of significance to identify malignant transformation, which is of utmost clinical significance.

Diagnostic value of whole-body MRI in Opsoclonus-myoclonus syndrome: a clinical case series (3 case reports).

BACKGROUND: Opsoclonus-myoclonus syndrome (OMS) is a rare clinical disorder and typically occurs in association with occult neuroblastic tumor in pediatric patients. I-123 metaiodobenzylguanidine (mIBG) scintigraphy is widely adopted as screening procedure in patients with suspected neuroblastic tumor. Also, contrast-enhanced magnetic resonance imaging (MRI) or computed tomography (CT) are involved in the imaging workup, primarily for the assessment of the primary tumor region. However, the diagnostic value of whole-body MRI (WB-MRI) for the detection of occult neuroblastic tumor in pediatric patients presenting with OMS remains unknown. CASE PRESENTATION: We present three cases of patients with OMS, in whom WB-MRI revealed occult neuroblastic tumor masses, whereas scintigraphy was inconclusive: In a 17 months old girl with OMS, WB-MRI revealed a paravertebral mass. After thoracoscopic resection, histopathology revealed a ganglioneuroblastoma. A 13 months old boy presenting with OMS WB-MRI detected a tumor of the left adrenal gland; histopathology demonstrated a ganglioneuroblastoma after adrenalectomy. In a 2 year old boy with OMS, immunoscintigraphy at the time of diagnosis was inconclusive. At the age of 13 years, a WB-MRI was performed due to persistent neurological symptoms, revealing a paravertebral retroperitoneal mass, which was classified as ganglioneuroblastoma. CONCLUSION: In OMS, particularly in the setting of inconclusive scintigraphy, WB-MRI may be considered as a valuable alternative in the early phase of diagnostic work-up.

Functional magnetic resonance urography in infants: feasibility of a feed-and-sleep technique.

BACKGROUND: Functional magnetic resonance (MR) urography has been well established in the diagnostic workup of congenital anomalies of kidneys and urinary tract, though long acquisition time requires sedation or general anesthesia in infants. OBJECTIVE: To evaluate the success rate of an optimized functional MR urography protocol in infants carried out in natural sleep. MATERIALS AND METHODS: We retrospectively evaluated all functional MR urographies performed under general anesthesia or during natural sleep in infants younger than 1 year between 2010 and 2017 and rated image quality in both cohorts using a 3-point Likert scale. We tested the analyzability of functional sequences using a free available software. We also calculated examination time. Finally, we compared examinations in natural sleep and those with general anesthesia using independent t-test for continuous data and Mann-Whitney U test for categorical data. RESULTS: Functional MR urography could be performed successfully during natural sleep in 38 of 42 (90%) infants younger than 10 months. Four examinations were aborted before contrast medium was administrated. In the same period, 19 functional MR urographies were performed successfully under general anesthesia. Although image quality was significantly better in this group (P<0.0001), image quality was at least diagnostic in all finished examinations in natural sleep, and the functional analyzability was given in all completed examinations. There was a significant saving in examination time during natural sleep (P<0.001). CONCLUSION: Functional MR urography can be successfully performed in natural sleep in infants younger than 10 months.

Pathogenesis, imaging and clinical characteristics of CF and non-CF bronchiectasis.

Bronchiectasis is a common feature of severe inherited and acquired pulmonary disease conditions. Among inherited diseases, cystic fibrosis (CF) is the major disorder associated with bronchiectasis, while acquired conditions frequently featuring bronchiectasis include post-infective bronchiectasis and chronic obstructive pulmonary disease (COPD). Mechanistically, bronchiectasis is driven by a complex interplay of inflammation and infection with neutrophilic inflammation playing a predominant role. The clinical characterization and management of bronchiectasis should involve a precise diagnostic workup, tailored therapeutic strategies and pulmonary imaging that has become an essential tool for the diagnosis and follow-up of bronchiectasis. Prospective future studies are required to optimize the diagnostic and therapeutic management of bronchiectasis, particularly in heterogeneous non-CF bronchiectasis populations.

POST-TEXT III and IV Hepatoblastoma: Extended Hepatic Resection Avoids Liver Transplantation in Selected Cases.

OBJECTIVE: To analyze the outcome of hepatoblastoma (HB) patients presenting with post treatment extent of disease (POST-TEXT) stages III and IV after neoadjuvant chemotherapy. BACKGROUND: Primary liver transplantation has been advocated as surgical treatment for children with HB involving 3 or 4 sectors at diagnosis. However, in some cases, tumors seem resectable after chemotherapy through aggressive use of nontransplant surgical procedures. METHODS: Data of 27 HB patients were reviewed, undergoing extended liver resection for POST-TEXT III or IV tumors after chemotherapy between 1992 and 2015. Median follow-up was 58 months (range 9-188). RESULTS: Median age at surgery was 18.2 months (interquartile range 10.8-32.5). Staging of the children after chemotherapy revealed POST-TEXT III in 21 and POST-TEXT IV in 6 cases. In 2 children, the hepatic resection was performed under cardiopulmonary bypass because of extended vena cava thrombosis; in 2 patients, a simultaneous sternotomy was performed for resection of bilateral lung metastases. The 5-year overall survival rate was 80.7%. CONCLUSIONS: Aggressive surgical resection is a successful approach in some patients with POST-TEXT III and IV HB who otherwise would be candidates for liver transplantation. These children should undergo central review and should be surgically managed at centers of excellence for pediatric liver surgery. Despite challenging surgical procedures and complex clinical courses, the patients benefit from avoidance of morbidities of organ transplant. However, preparation of backup liver transplantation should be considered in selected cases.

Contrast-Enhanced High-Pitch Computed Tomography in Pediatric Patients Without Electrocardiography Triggering and Sedation: Comparison of Cardiac Image Quality With Conventional Multidetector Computed Tomography.

OBJECTIVE: The aim of this study was to compare image quality of anatomical cardiac details without electrocardiography triggering, sedation, or heart rate-regulating drugs in contrast-enhanced pediatric chest computed tomography (CT), using high-pitch CT (HPCT) versus conventional pitch-mode technique (multidetector CT [MDCT]). METHODS: After written informed consent, 55 patients (median age, 11 years; range, 3-17 years) were prospectively included in this institutional review board-approved study. Patients underwent clinically indicated, contrast-enhanced MDCT or HPCT of the chest.Image quality was assessed evaluating morphological criteria on a 3-point scale (from 1, high, to 3, low detail) and summed up in a global score (from 4, best, to 12, poor image quality). Artifacts were analyzed correspondingly (from 3, low, to 9, severe artifacts). Effective dose and size-specific dose estimate were calculated for all scans. RESULTS: Cardiac image quality was higher in HPCT than in MDCT (7.1 [1.6] vs 8.8 [1.9], P < 0.001). Nevertheless, HPCT showed limitations in image quality, especially concerning the heart valves (2.5 [0.6] and 1.7 [0.5]) and coronary arteries (1.8 [0.6). Artifact score (3.4 [0.6 vs 5.1 [0.9, P < 0.001), effective dose (1.6 [1.3] vs 2.3 [1.6] mSv, P = 0.047), and size-specific dose estimate (2.5 [1.7] vs 4.1 [2.3] mGy, P = 0.002) were lower in HPCT compared with those in MDCT. CONCLUSIONS: In pediatric patients, contrast-enhanced HPCT of the chest provides high image quality without electrocardiography triggering or sedation, although image quality is somewhat limited for a detailed depiction of cardiac anatomy.

Defining optimal tracer activities in pediatric oncologic whole-body 18F-FDG-PET/MRI.

PURPOSE: To explore the feasibility of reducing administered tracer activities and to assess optimal activities for combined 18F-FDG-PET/MRI in pediatric oncology. METHODS: 30 18F-FDG-PET/MRI examinations were performed on 24 patients with known or suspected solid tumors (10 girls, 14 boys, age 12 ± 5.6 [1-18] years; PET scan duration: 4 min per bed position). Low-activity PET images were retrospectively simulated from the originally acquired data sets using randomized undersampling of list mode data. PET data of different simulated administered activities (0.25-2.5 MBq/kg body weight) were reconstructed with or without point spread function (PSF) modeling. Mean and maximum standardized uptake values (SUVmean and SUVmax) as well as SUV variation (SUVvar) were measured in physiologic organs and focal FDG-avid lesions. Detectability of organ structures and of focal 18F-FDG-avid lesions as well as the occurrence of false-positive PET lesions were assessed at different simulated tracer activities. RESULTS: Subjective image quality steadily declined with decreasing tracer activities. Compared to the originally acquired data sets, mean relative deviations of SUVmean and SUVmax were below 5 % at 18F-FDG activities of 1.5 MBq/kg or higher. Over 95 % of anatomic structures and all pathologic focal lesions were detectable at 1.5 MBq/kg 18F-FDG. Detectability of anatomic structures and focal lesions was significantly improved using PSF. No false-positive focal lesions were observed at tracer activities of 1 MBq/kg 18F-FDG or higher. Administration of 18F-FDG activities of 1.5 MBq/kg is, thus, feasible without obvious diagnostic shortcomings, which is equivalent to a dose reduction of more than 50 % compared to current recommendations. CONCLUSION: Significant reduction in administered 18F-FDG tracer activities is feasible in pediatric oncologic PET/MRI. Appropriate activities of 18F-FDG or other tracers for specific clinical questions have to be further established in selected patient populations.

Ultra low-dose VCUG in children using a modern flat detectorunit.

OBJECTIVES: To assess dose area products (DAP) and effective doses (ED) of voiding cystourethrography (VCUG) in children using optimized protocols on a modern flat detector unit. METHODS: DAP and ED were evaluated in 651 VCUG (316 girls, median age: 2.25 years) between 2009 and 2012. DAP was analyzed in relation to patient characteristics (gender, age, presence of pathological findings) and experience of performing physician using analysis of variance. ED values were estimated using adapted conversion factors from the literature. Diagnostic image quality was validated by two experienced physicians using a 3-point scale. RESULTS: Median DAP/ED was 0.5 cGycm(2)/4.56 µSv (boys: 0.6 cGycm(2)/6.16 µSv; girls: 0.4 cGycm(2)/3.54 µSv). In 300 studies without pathologic findings DAP was 0.35 cGycm(2), whereas 351 studies with pathologic findings had a median DAP of 0.7 cGycm(2). No significant relationship between DAP and experience of radiologist was observed. Image validation resulted in an overall good to excellent rating. CONCLUSIONS: DAP and ED can be markedly reduced in paediatric VCUG performed with optimized protocols on modern equipment without a noticeable decrease in diagnostic image quality. KEY POINTS: • Voiding cystourethrography is a comprehensive examination in diagnosing vesicoureteral reflux (VUR). • Radiation reduction is achieved in VCUG through modern equipment and optimized protocols. • Low-dose VCUG is possible without noticeable decrease in diagnostic image quality.