ATM germline pathogenic variants affect outcomes in children with ataxia-telangiectasia and hematological malignancies.

Ataxia-telangiectasia (A-T) is an autosomal-recessive disorder caused by pathogenic variants (PVs) of the ATM gene. Children with A-T are predisposed to hematological malignancies. We aimed to investigate their characteristics and outcomes in order to generate data-based treatment recommendations. In this multinational, observational study we report 202 patients aged ≤25 years with A-T and hematological malignancies from 25 countries. Ninety-one patients (45%) presented with mature B-cell lymphomas, 82 (41%) with acute lymphoblastic leukemia/lymphoma, 21(10%) with Hodgkin lymphoma and eight (4%) with other hematological malignancies. Four-year overall survival and event-free survival (EFS) were 50.8% (95% CI 43.6-59.1) and 47.9% (95% CI 40.8-56.2), respectively. Cure rates have not significantly improved over the last four decades (p=.76). The major cause of treatment failure was treatment-related mortality (TRM) with a four-year cumulative incidence of 25.9% (95% CI 19.5-32.4). Germline ATM PVs were categorized as null or hypomorphic and patients with available genetic data (n=110) were classified as having absent (n=81) or residual (n=29) ATM kinase activity. Four-year EFS was 39.4% (95% CI 29-53.3) vs 78.7% (95% CI 63.7-97.2), (p<.001), and TRM rates were 37.6% (95% CI 26.4-48.7) vs 4.0% (95% CI 0-11.8), (p=.017), for those with absent and residual ATM kinase activity, respectively. Absence of ATM kinase activity was independently associated with decreased EFS (HR=0.362, 95% CI 0.16-0.82; p=.009) and increased TRM (HR=14.11, 95% CI 1.36-146.31; p=.029). Patients with A-T and leukemia/lymphoma may benefit from de-escalated therapy for patients with absent ATM kinase activity and near-standard therapy regimens for those with residual kinase activity.

EBV-driven lymphoid neoplasms associated with pediatric ALL maintenance therapy.

The development of a second malignancy after the diagnosis of childhood acute lymphoblastic leukemia (ALL) is a rare event. Certain second malignancies have been linked with specific elements of leukemia therapy, yet the etiology of most second neoplasms remains obscure and their optimal management strategies are unclear. This is a first comprehensive report of non-Hodgkin lymphomas (NHLs) following pediatric ALL therapy, excluding stem-cell transplantation. We analyzed data of patients who developed NHL following ALL diagnosis and were enrolled in 12 collaborative pediatric ALL trials between 1980-2018. Eighty-five patients developed NHL, with mature B-cell lymphoproliferations as the dominant subtype (56 of 85 cases). Forty-six of these 56 cases (82%) occurred during or within 6 months of maintenance therapy. The majority exhibited histopathological characteristics associated with immunodeficiency (65%), predominantly evidence of Epstein-Barr virus-driven lymphoproliferation. We investigated 66 cases of post-ALL immunodeficiency-associated lymphoid neoplasms, 52 from our study and 14 additional cases from a literature search. With a median follow-up of 4.9 years, the 5-year overall survival for the 66 patients with immunodeficiency-associated lymphoid neoplasms was 67.4% (95% confidence interval [CI], 56-81). Five-year cumulative risks of lymphoid neoplasm- and leukemia-related mortality were 20% (95% CI, 10.2-30) and 12.4% (95% CI, 2.7-22), respectively. Concurrent hemophagocytic lymphohistiocytosis was associated with increased mortality (hazard ratio, 7.32; 95% CI, 1.62-32.98; P = .01). A large proportion of post-ALL lymphoid neoplasms are associated with an immunodeficient state, likely precipitated by ALL maintenance therapy. Awareness of this underrecognized entity and pertinent diagnostic tests are crucial for early diagnosis and optimal therapy.

Pneumocystis jirovecii pneumonia in paediatric acute lymphoblastic leukaemia: A report from the multi-international clinical trial AIEOP-BFM ALL 2009.

Pneumocystis jirovecii can cause life-threatening pneumonia (PjP), and patients with haematological malignancies are at high risk of this infection. Prophylactic measures have significantly decreased morbidity and mortality, but there is a paucity of contemporary data on the incidence and clinical course of PjP in well-defined and homogenous patient populations, such as children suffering from acute lymphoblastic leukaemia (ALL). In the multi-international trial AIEOP-BFM ALL2009, PjP was diagnosed in six children (incidence 1/1000) and was associated with insufficient prophylaxis in five of them. Although none of the patients died of PjP, the long-term impact of the infection is unclear.

Melanoma of the central nervous system based on neurocutaneous melanocytosis in childhood: A rare but fatal condition.

BACKGROUND: Melanomas of the central nervous system (CNS) based on neurocutaneous melanocytosis (NCM) are exceptionally rare in childhood and have been described only sporadically. Rapidly progressive disease may represent a major challenge for treating physicians, especially given the limited knowledge about this condition. This analysis aimed to increase knowledge about the occurrence and treatment of these malignancies. PROCEDURE: Data on diagnosis, treatment, and outcome of patients aged 0-18 years with CNS melanoma based on NCM recorded in the German Registry for Rare Pediatric Tumors (STEP registry) were analyzed. Additionally, published case reports on this condition were analyzed. RESULTS: In STEP, five patients with leptomeningeal melanoma based on NCM were identified, with a median age at melanoma diagnosis of 3.7 years. Various multimodal treatments were performed: (partial) resection (n = 4), irradiation (n = 2), trametinib (n = 3), different cytostatics (n = 2), and anti-GD2 immunotherapy (n = 1). All patients died between 0.3 and 0.8 years after diagnosis. Including published case reports, 27 patients were identified with a median age of 2.8 years at melanoma diagnosis (range: 0.2-16.6). Fourteen of 16 cases with reported data had a NRAS alteration (88%), particularly NRAS p.Q61K (85%). In the expanded cohort, no patient survived longer than 1 year after diagnosis despite multimodal therapy (including trametinib; n = 9), with a median survival of 0.4 years (range 0.1-0.9). CONCLUSIONS: CNS melanomas based on NCM in childhood are aggressive malignancies without curative treatment to date. Therapeutic approaches must be individualized. Genetic tumor sequencing is essential to improve understanding of tumorigenesis and potentially identify new therapeutic targets.

Pediatric cancer patients vaccinated against SARS-CoV-2-a clinical and laboratory follow-up.

BACKGROUND: Vaccination against SARS-CoV-2 is recommended for cancer patients. However, long-term data on the effectiveness in the pediatric setting are lacking. METHODS: Pediatric patients < 18 years on active treatment for cancer and without prior SARS-CoV-2 infection received three doses of an mRNA vaccine. The clinical course and humoral and cellular immunity were evaluated at the end of the follow-up period of ≥ 1 year after the third dose of vaccine. RESULTS: SARS-CoV-2 infection occurred in 17 of 19 analyzed patients (median age 16.5 years) during the follow-up period (median 17 months), but no severe symptoms were seen. At ≥ 1 year after the last SARS-CoV-2 antigen exposure, 4 of 17 patients had received the recommended booster vaccine. At the end of the follow-up period, all evaluable 15 patients had anti-SARS-CoV-2 receptor-binding domain IgG antibodies. Twelve of the 15 patients had neutralizing antibody titers ≥ 1:10 against the Delta variant and 12/15 and 13/15 against the BA.1 and BA.5 variants, respectively. Specific T cells against SARS-CoV-2 antigens were seen in 9/13 patients. CONCLUSIONS: Most SARS-CoV-2-vaccinated pediatric cancer patients had SARS-CoV-2 infections and limited interest in booster vaccination. At 1 year after the last antigen exposure, which was mostly an infection, humoral immune responses remained strong. TRIAL REGISTRATION: German Clinical Trials Register DRKS00025254, May 26, 2021.

New and emerging options for management of invasive fungal diseases in paediatric patients.

Invasive fungal diseases (IFDs) play an important role in the supportive care of paediatric patients with acute leukaemia and those undergoing allogeneic haematopoietic cell transplantation, and they are associated with significantly decreased overall survival rates in affected individuals. Relative to adults, children and adolescents are distinct in terms of host biology, predisposing conditions, presentation and epidemiology of fungal diseases, and in the pharmacology of antifungal agents. The paediatric development of antifungal agents has moved forward in a coordinated manner, and major advances have been made regarding concepts and recommendations for the prevention and treatment of IFDs. However, antifungal therapy is increasingly complex, and a solid knowledge of the available options is needed more than ever for successful management. This narrative review provides a summary of the paediatric development of agents that have been recently approved (anidulafungin, posaconazole) or are in advanced stages of development (isavuconazole). It also reviews the emerging evidence for the efficacy of echinocandins for prophylaxis of invasive aspergillosis, presents new data on alternative dosing regimens of echinocandins and voriconazole, and provides a brief overview of new antifungal agents in clinical development that are expected to be developed for paediatric patients.

Longitudinal Immune Response to 3 Doses of Messenger RNA Vaccine Against Coronavirus Disease 2019 (COVID-19) in Pediatric Patients Receiving Chemotherapy for Cancer.

Our study in 21 pediatric cancer patients demonstrates that 3 doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA vaccine (BioNTech/Pfizer) elicited both humoral and cellular immunity in most patients during chemotherapy. Immunity was stronger in children with solid tumors and during maintenance therapy compared to those with hematological malignancies or during intensive chemotherapy. Clinical Trials Registration.ȃGerman Registry for Clinical Trials (DRKS00025254).

Performance of the beta-glucan test for the diagnosis of invasive fusariosis and scedosporiosis: a meta-analysis.

The (1→3)-ß-D-glucan (BDG) is a component of the fungal cell wall that can be detected in serum and used as an adjunctive tool for the diagnosis of invasive mold infections (IMI) in patients with hematologic cancer or other immunosuppressive conditions. However, its use is limited by modest sensitivity/specificity, inability to differentiate between fungal pathogens, and lack of detection of mucormycosis. Data about BDG performance for other relevant IMI, such as invasive fusariosis (IF) and invasive scedosporiosis/lomentosporiosis (IS) are scarce. The objective of this study was to assess the sensitivity of BDG for the diagnosis of IF and IS through systematic literature review and meta-analysis. Immunosuppressed patients diagnosed with proven or probable IF and IS, with interpretable BDG data were eligible. A total of 73 IF and 27 IS cases were included. The sensitivity of BDG for IF and IS diagnosis was 76.7% and 81.5%, respectively. In comparison, the sensitivity of serum galactomannan for IF was 27%. Importantly, BDG positivity preceded the diagnosis by conventional methods (culture or histopathology) in 73% and 94% of IF and IS cases, respectively. Specificity was not assessed because of lacking data. In conclusion, BDG testing may be useful in patients with suspected IF or IS. Combining BDG and galactomannan testing may also help differentiating between the different types of IMI.

IF and IS are severe fungal infections for which diagnosis is often delayed. This meta-analysis shows that beta-glucan testing in serum had a sensitivity of about 80% for IF/IS and could detect the disease earlier compared to conventional diagnostic tests.

No role for electroencephalogram in the initial work-up of pediatric acute lymphoblastic leukemia.

PURPOSE: The purpose of this study was to verify whether there is a prognostic benefit of electroencephalogram (EEG) performed during initial work-up of children with newly diagnosed acute lymphoblastic leukemia (ALL). METHODS: In this retrospective monocenter study, we analyzed the value of electroencephalogram (EEG) performed during initial work-up of children with newly diagnosed acute lymphoblastic leukemia (ALL). All pediatric patients were included in this study who were diagnosed with de novo ALL in our institution between January 1, 2005, and December 31, 2018, and in whom an EEG was performed for initial work-up within 30 days of diagnosis of ALL. EEG findings were associated with the occurrence and the etiology of neurologic complications occurring during intensive chemotherapy. RESULTS: Out of 242 children, EEG revealed pathological findings in 6 patients. Two of them developed a seizure at a later time point due to adverse effects of chemotherapy, whereas 4 children had an uneventful clinical course. In contrast, 18 patients with normal initial EEG findings developed seizures during therapy for different reasons. CONCLUSION: We conclude that routine EEG does not predict seizure susceptibility in children with newly diagnosed ALL and is unnecessary in the initial work-up as EEG investigation in young and often sick children requires sleep deprivation and/or sedation, and our data demonstrate no benefit in predicting neurological complications.

Voriconazole plasma concentrations and dosing in paediatric patients below 24 months of age.

Voriconazole (VCZ) is an important first-line option for management of invasive fungal diseases and approved in paediatric patients ≥24 months at distinct dosing schedules that consider different developmental stages. Information on dosing and exposures in children <24 months of age is scarce. Here we report our experience in children <24 months who received VCZ due to the lack of alternative treatment options. This retrospective analysis includes 50 distinct treatment episodes in 17 immunocompromised children aged between 3 and <24 months, who received VCZ between 2004 and 2022 as prophylaxis (14 patients; 47 episodes) or as empirical treatment (3 patients; 3 episodes) by mouth (46 episodes) or intravenously (4 episodes) based on contraindications, intolerance or lack of alternative options. Trough concentrations were measured as clinically indicated, and tolerability was assessed based on hepatic function parameters and discontinuations due to adverse events (AEs). VCZ was administered for a median duration of 10 days (range: 1-138). Intravenous doses ranged from 4.9 to 7.0 mg/kg (median: 6.5) twice daily, and oral doses from 3.8 to 29 mg/kg (median: 9.5) twice daily, respectively. The median trough concentration was 0.63 mg/L (range: 0.01-16.2; 38 samples). Only 34.2% of samples were in the recommended target range of 1-6 mg/L; 57.9% had lower and 7.9% higher trough concentrations. Hepatic function parameters analysed at baseline, during treatment and at end of treatment did not show significant changes during VCZ treatment. There was no correlation between dose and exposure or hepatic function parameters. In three episodes, VCZ was discontinued due to an AE (6%; three patients). In conclusion, this retrospective analysis reveals no signal for increased toxicity in paediatric patients <24 months of age. Empirical dosing resulted in mostly subtherapeutic exposures which emphasises the need for more systematic study of the pharmacokinetics of VCZ in this age group.

[Therapeutic Strategies In Children And Adolescents With Langerhans Cell Histiocytosis]. / Therapiestrategien bei Kindern und Jugendlichen mit Langerhanszell Histiozytosen.

The current standard therapy for children and adolescents with newly diagnosed Langerhans cell histiocytosis (LCH) is based on the two drugs prednisone and vinblastine. In patients with insufficient treatment response or disease relapse, the choice of second-line treatment depends on risk organ involvement (liver, spleen, and hematopoietic system). This article will give an overview of current data concerning therapeutic options in the different settings of children and adolescents with LCH. Due to limited evidence, these strategies have not been described in detail in the updated guidelines on pediatric LCH. In addition, the use of targeted therapy such as MAP-kinase inhibitors will be discussed. The reference center for LCH should be contacted if therapeutic options beyond the standard regimen are considered for treatment. All children and adolescents with LCH should be enrolled in registries or prospective studies.

Progression and Relapse of Pediatric Soft Tissue Sarcoma: Individualized Approach of Treatment - Experience from a Major Pediatric Cancer Center in Europe.

BACKGROUND: The outcome of children with refractory or relapsed soft tissue sarcoma (STS) is extremely poor. Whereas larger clinical trials evaluated specific treatment modalities, real-life data on individual multimodal therapeutic strategies, given alone or in combination, are scarce. PATIENTS AND METHODS: We retrospectively analyzed the clinical course of 18 pediatric patients with progression of or relapsed STS treated between 2008 and 2018 in our institution. RESULTS: A total of 18 patients (median age 12.4 years) suffered from progression or relapse of alveolar (n=7), embryonal (n=5), undifferentiated (n=2) rhabdomyosarcoma or desmoplastic small round cell tumor (n=4). 14 patents had an initial stage IV disease. All but one patient died. Median survival was 12.5 months. Shortest survival was seen in patients with systemic progression of the disease, longest in patients with local relapse. Patients with an Oberlin score<2 at the time of relapse had a significant longer time of survival than those with a score≥2. No significant advantage of a specific therapeutic modality was observed. DISCUSSION: We critically analyzed the clinical course in the real-life setting, in which various treatment options were applied to an individual patient according to the best of available data. We observed that some patients died within a short period of time despite multiple treatment modalities, which underlines the need for better prognostic parameters. CONCLUSION: In addition to well characterized clinical factors such as local or systemic relapse, the Oberlin score could be helpful in counselling patients and their families for choosing the best strategy of care.

[Time to Antibiotics (TTA) - Reassessment from the German Working Group for Fever and Neutropenia in Children and Adolescents (DGPI/GPOH)]. / Time to Antibiotics (TTA) ­ Überlegungen der Arbeitsgruppe Fieber bei Granulozytopenie im Kindes- und Jugendalter (GPOH/DGPI) zu einer Neubewertung.

BACKGROUND: The current German guidance from 2016 recommends a Time to Antibiotics (TTA) of<60 min in children and adolescents with febrile neutropenia (FN). METHODS: Critical analysis of available studies and recent meta-analyses, and discussion of the practical consequences in the FN working group of the German Societies for Paediatric Oncology and Haematology and Paediatric Infectious Diseases. RESULTS: The available evidence does not support a clinically significant outcome benefit of a TTA<60 min in all paediatric patients with FN. Studies suggesting such a benefit are biased (mainly triage bias), use different TTA definitions and display further methodical limitations. In any case, a TTA<60 min remains an essential component of the 1st hour-bundle in paediatric cancer patients with septic shock or sepsis with organ dysfunction. CONCLUSION: Provided that all paediatric FN patients receive a structured medical history and physical examination (including vital signs) by experienced and trained medical personnel in a timely fashion, and provided that a sepsis triage and management bundle is established and implemented, a TTA lower than 3 hours is sufficient and reasonable in stable paediatric cancer patients with FN.

[Updated AWMF Guideline on the Diagnosis and Treatment of Langerhans cell Histiocytosis in Children and Adolescents]. / Aktualisierte AWMF Leitlinie zur Diagnostik und Therapie der Langerhanszell Histiozytose (LCH) im Kindes- und Jugendalter.

Langerhans cell Histiocytosis is a rare neoplastic disease, which occurs mainly in children and adolescents. The disease may affect any organ, and therefore, the clinical symptoms vary widely. Some patients have a spontaneous remission of the disease, whereas others experience a rapid and potentially lethal clinical course. The therapeutic approach depends on the extent of the disease, and reaches from a watch-and-wait strategy to chemotherapy with the standard drugs vinblastine and prednisone. The identification of mutations in the MAPK-pathway resulted in growing interest in targeted therapy using compounds such as the BRAF inhibitors. Chronic relapses and permanent sequelae are important problems of LCH and are the focus of current research.

SARS-CoV-2 in pediatric cancer: a systematic review.

The outbreak of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019 in Wuhan challenges pediatric oncologists in an unexpected way. We provide a comprehensive overview, which systematically summarizes and grades evidence (QoE) on SARS-CoV-2 infections in pediatric cancer patients at 1.5 years of pandemic. A systematic literature search in PubMed combined with an additional exploratory literature review in other international databases was conducted to identify studies on children (aged < 18 years) with a malignant disease and COVID-19 infections. In total, 45 reports on 1003 pediatric cancer patients with SARS-CoV-2 infections were identified out of 1397 reports analyzed. The clinical course of COVID-19 was reported mild or moderate in 358 patients (41.7%), whereas 11.1% of patients showed severe COVID-19. In 12.7% of patients, chemotherapy was postponed, whereas 19% of patients with different underlying malignancies received chemotherapy during SARS-CoV-2 infection. Twenty-five patients with SARS-CoV-2 infections died, potentially related to COVID-19. CONCLUSION: Despite a favorable COVID-19 outcome in most pediatric cancer patients, the morbidity is reported higher than in children without comorbidities. However, no severe COVID-19 complications were associated to the continuation of chemotherapy in some cohort studies and reports on two patients. Therefore, the risk of cancer progress or relapse due to interruption of chemotherapy has carefully to be weighed against the risk of severe COVID-19 disease with potentially fatal outcome. WHAT IS KNOWN: • Most of pediatric patients with malignant diseases show an asymptomatic, mild or moderate clinical course of SARS-CoV-2 infection. • Current need for a basis for decision-making, whether to stop or interrupt cancer treatment in a patient infected with SARS-CoV-2, and when to continue chemotherapy. WHAT IS NEW: • Review results comprising over 1000 pediatric COVID-19 cancer patients confirm mild courses of SARS-CoV-2 infection in most patients but also show the attributable mortality is at least 10 times higher compared to reports on hospitalized children without comorbidities. • Review identifies that chemotherapy was continued despite SARS-CoV-2 positivity in 18% of patients with individual chemotherapy modification according to the clinical course of SARS-CoV-2 infection and existing comorbidities. On this basis, no severe COVID-19 complications were associated to the continuation of chemotherapy in several cohort studies and two case reports.

8th European Conference on Infections in Leukaemia: 2020 guidelines for the diagnosis, prevention, and treatment of invasive fungal diseases in paediatric patients with cancer or post-haematopoietic cell transplantation.

Paediatric patients with cancer and those undergoing allogeneic haematopoietic cell transplantation have an increased susceptibility to invasive fungal diseases. In addition to differences in underlying conditions and comorbidities relative to adults, invasive fungal diseases in infants, children, and adolescents are unique in terms of their epidemiology, the validity of current diagnostic methods, the pharmacology and dosing of antifungal agents, and the absence of phase 3 clinical trials to provide data to guide evidence-based interventions. To re-examine the state of knowledge and to further improve invasive fungal disease diagnosis, prevention, and management, the 8th European Conference on Infections in Leukaemia (ECIL-8) reconvened a Paediatric Group to review the literature and to formulate updated recommendations according to the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and European Confederation of Medical Mycology (ECMM) grading system, which are summarised in this Review.

8th European Conference on Infections in Leukaemia: 2020 guidelines for the use of antibiotics in paediatric patients with cancer or post-haematopoietic cell transplantation.

Paediatric patients with cancer and those undergoing haematopoietic cell transplantation are at high risk of bacterial infections. The 8th European Conference on Infections in Leukaemia (ECIL-8) convened a Paediatric Group to review the literature and to formulate recommendations for the use of antibiotics according to the European Society of Clinical Microbiology and Infectious Diseases grading system. The evaluation of antibacterial prophylaxis included mortality, bloodstream infection, febrile neutropenia, emergence of resistance, and adverse effects as endpoints. Initial antibacterial therapy and antibiotic de-escalation or discontinuation focused on patients with a clinically stable condition and without previous infection or colonisation by resistant bacteria, and on patients with a clinically unstable condition or with previous infection or colonisation by resistant bacteria. The final considerations and recommendations of the ECIL-8 Paediatric Group on antibacterial prophylaxis, initial therapy, and de-escalation strategies are summarised in this Policy Review.

Additive Prognostic Impact of Gastrointestinal Involvement in Severe Multisystem Langerhans Cell Histiocytosis.

OBJECTIVE: To evaluate the prognostic impact of gastrointestinal involvement on the survival of children with Langerhans cell histiocytosis (GI-LCH) registered with the international clinical trials of the Histiocyte Society. STUDY DESIGN: This was a retrospective analysis of 2414 pediatric patients registered onto the consecutive trials DAL-HX 83, DAL-HX 90, LCH-I, LCH-II, and LCH-III. RESULTS: Among the 1289 patients with single-system LCH, there was no single case confined to the GI tract; 114 of 1125 (10%) patients with multisystem LCH (MS-LCH) had GI-LCH at initial presentation. GI-LCH was significantly more common in children aged <2 years at diagnosis (13% vs 6% in those aged >2 years; P < .001) and in those with risk organ involvement (15% vs 6% in those without risk organ involvement; P < .001). The 5-year overall survival (OS) in patients without risk organ involvement was excellent irrespective of GI disease (98% vs 97% in patients with GI-LCH; P = .789). In patients with risk organ involvement, the 5-year OS was 51% in 70 patients with GI-LCH vs 72% in 394 patients without GI-LCH (P < .001). CONCLUSIONS: GI-LCH has an additive unfavorable prognostic impact in children with MS-LCH and risk organ involvement. The emerding need for more intensive or alternative treatments mandates prospective evaluation.

[Antibacterial Prophylaxis in Children and Adolescents Undergoing Therapy for Cancer - Statement of the Society of Pediatric Oncology and Hematology (GPOH) and of the German Society for Pediatric Infectious Diseases (DGPI) on Two Current International Guidelines]. / Antibakterielle Prophylaxe in der Pädiatrischen Hämatologie und Onkologie.

Immunocompromised children and adolescents receiving treatment for cancer have an increased risk for potentially life-threatening infectious complications such as blood stream infections with Gram-positive and Gram-negative pathogens. Therefore, several centers for Pediatric Hematology and Oncology administer antibacterial prophylaxis to these patients to lower morbidity and mortality. Two pediatric specific guidelines on antibacterial prophylaxis were recently published. One of these guidelines was drawn up by an international group of pediatric experts of Europe, North and South America and Australia. The other guideline was prepared by an European group convened at the Eighth European Conference on Infections in Leukaemia (ECIL-8). In this review article, the working groups "Infections" of the Society of Pediatric Oncology and Hematology (GPOH) and "Fever in the neutropenic host" of the German Society for Pediatric Infectious Diseases" (DGPI) summarize the available data from randomized studies, systematic reviews and meta-analyses on antibacterial prophylaxis as well of current data on the emergence of resistance and discuss methodological aspects and the recommendations of the two guidelines.

Pediatric CNS imaging and long-term effects of irradiation in pediatric oncology patients.

BACKGROUND: The aim of this study was to evaluate post-irradiation changes in the central nervous system (CNS) detected using magnetic resonance (MR) imaging. METHODS: Magnetic resonance images of 15 children with CNS tumors treated through whole-brain irradiation over 10 years were reviewed retrospectively. Variables such as age at the time of irradiation, total radiation dose, treatment length, and time interval between irradiation and MR changes, were evaluated. RESULTS: All patients included in the study had imaging abnormalities of the CNS. Eight patients (53%) developed CNS abnormalities within a short period of time - only a few months after irradiation (mean 4.8 months). Seven patients (47%) developed CNS abnormalities within a long time interval after treatment (mean 4.6 years). In almost all patients, a T2 increase in supra- and infratentorial white matter was observed. Follow-up examinations showed nine patients (60%) with cerebellar atrophy. CONCLUSIONS: In this sample of pediatric patients who underwent whole-brain irradiation, the time receiving irradiation was not related to the severity of the MR changes. A correlation between the age of the child or the length of the radiotherapy and the extent of the changes could not be confirmed. However, we observed a trend towards stronger brain parenchymal degeneration with cystic changes in the younger age group of children in our sample. Older children who received irradiation seem to be more susceptible to vascular dysplasia with cavernous hemangiomas and microbleeding.