Metastatic adult-type non-rhabdomyosarcoma soft tissue sarcomas in children and adolescents: A cohort study from the European paediatric Soft tissue sarcoma Study Group.

BACKGROUND: Limited data exist on the clinical behavior of pediatric non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) with distant metastases at onset, and a clear standard of care has not yet been defined. METHODS: This cohort study reports on pediatric adult-type metastatic NRSTS enrolled in two concurrent prospective European studies, i.e., the randomized BERNIE study and the single-arm MTS 2008 study developed by the European paediatric Soft tissue sarcoma Study Group. Treatment programs were originally designed for patients with metastatic rhabdomyosarcoma, i.e., nine courses of multidrug chemotherapy (with or without bevacizumab in the BERNIE study), followed by 12 cycles of maintenance therapy, whereas radiotherapy and/or surgery (on primary tumor and/or metastases) were delayed until after seven courses of chemotherapy had been administered. RESULTS: The study included 61 patients <21 years old treated from July 2008 to December 2016. The lung was the site of metastases in 75% of the cases. All patients received multi-agent chemotherapy, 44% had local therapy to primary tumor, and 18% had treatment of metastases. Median time to progression/relapse was 6 months. A high rate of tumor progression was observed during the initial part of the chemotherapy program. With a median follow-up of 41.5 months (range, 2-111 months), 3-year event-free survival and overall survival were 15.4% (95% confidence interval [CI], 7.6-25.7) and 34.9% (95% CI, 22.7-47.5), respectively. There were no statistically significant differences in outcome depending on the type of treatment administered. CONCLUSIONS: The study confirmed the overall poor outcome for patients with metastatic NRSTS, whose treatment remains a challenge. PLAIN LANGUAGE SUMMARY: Pediatric non-rhabdomyosarcoma soft tissue sarcomas form a heterogeneous group of rare tumors. Although recent international studies have defined the standard of care for patients with localized disease, limited data are available on the clinical behavior of patients with distant metastases. This study on 61 metastatic cases treated on two prospective European protocols confirms that the chances of survival of such patients are often dismal and a standard treatment is still lacking.

Intra-abdominal desmoplastic small round cell tumor: The European pediatric Soft tissue sarcoma Study Group (EpSSG) experience.

BACKGROUND: This study describes the clinical findings of a consecutive series of pediatric and adolescent patients with a diagnosis of intra-abdominal desmoplastic small round cell tumor (DSRCT) prospectively enrolled in European pediatric Soft tissue sarcoma Study Group (EpSSG) protocols: the BERNIE study, the EpSSG MTS 2008 study, and the EpSSG NRSTS 2005 study. METHODS: Patients aged less than 21 years with a diagnosis of DSRCT arising in the abdomen were included. All trials recommended a multimodal approach including intensive multidrug chemotherapy and loco-regional treatment with surgery and/or radiotherapy whenever possible. RESULTS: The analysis included 32 cases (median age 13.7 years, male:female ratio 1.5:1). Three patients had localized tumors, seven had regionally disseminated disease, and 22 extraperitoneal metastases. All but one patient received multidrug chemotherapy and 11 had maintenance chemotherapy. Loco-regional treatment consisted of surgery only in seven cases, surgery plus adjuvant radiotherapy in 10, and radiotherapy only in six. Among the 17 cases who had radiotherapy, six had irradiation of the primary site, 10 had whole abdominopelvic radiotherapy plus boost to macroscopic residual disease, and one had irradiation to lung metastases only. With a median follow-up of 76 months (range: 18-124 months), 5-year event-free and overall survivals were 19.7% and 21.0%, respectively. Event-free survival was significantly worse for patients who did not receive loco-regional treatment (p-value .007). CONCLUSIONS: The study confirmed that the outcome of patients with DSRCT remains dismal and did not improve over recent years despite an intensive multimodal treatment approach.

Development of an intravenous chemotherapy intervention for children and adolescents with cancer administered by their parents at home (INTACTatHome).

BACKGROUND: Families of children and adolescents with cancer strive to maintain routines and normalcy during the child's treatment trajectory that requires frequent hospital visits. Intravenous chemotherapy at home can reduce time spent on the frequent hospital visits and mitigate disruption in daily life. Studies on home chemotherapy for children and adolescents with cancer are limited, as is knowledge of family and health care professionals' needs, and knowledge required to inform adaptation or replication of interventions in other settings. The aim of this study was to develop and describe an evidence-based home chemotherapy intervention that is feasible and safe for children and adolescents and suitable for future feasibility testing. METHODS: The Medical Research Council's guidance for developing complex interventions in health care and the framework of action developed by O'Cathain et al. was used as theoretical frameworks to structure the development process. A literature search, an ethnographic study, and interviews with clinical nurse specialists from adult cancer departments formed the evidence base. Educational learning theory to support and understand the intervention was identified. Stakeholder perspectives were explored in workshops with health care professionals and parent-adolescent interviews. Reporting was qualified using the GUIDED checklist. RESULTS: A stepwise educational program to teach parents how to administer low-dose chemotherapy (Ara-C) to their child at home and a simple and safe administration procedure were developed. Key uncertainties were identified, including barriers and facilitators impacting future testing, evaluation, and implementation. Causal assumptions and reasoning for how the intervention leads to short-term outcomes and long-term impact were clarified in a logic model. CONCLUSIONS: The iterative and flexible framework allowed for integration of existing evidence and new data and was successfully applied to the development process. The detailed report on the development process of the home chemotherapy intervention can enhance adaptation or replication of the intervention to other settings and thereby mitigate family disruption and stress of frequent hospital visits for these treatments. The study has informed the next phase of the research project that aims to test the home chemotherapy intervention in a prospective single-arm feasibility study. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT05372536.

Effects of germline DHFR and FPGS variants on methotrexate metabolism and relapse of leukemia.

Methotrexate (MTX) during maintenance therapy is essential for curing acute lymphoblastic leukemia (ALL), but dosing strategies aiming at adequate treatment intensity are challenged by interindividual differences in drug disposition. To evaluate genetic factors associated with MTX metabolism, we performed a genome-wide association study in 447 ALL cases from the Nordic Society for Pediatric Haematology and Oncology ALL2008 study, validating results in an independent set of 196 patients. The intergenic single-nucleotide polymorphism rs1382539, located in a regulatory element of DHFR, was associated with increased levels of short-chain MTX polyglutamates (P = 1.1 × 10-8) related to suppression of enhancer activity, whereas rs35789560 in FPGS (p.R466C, P = 5.6 × 10-9) was associated with decreased levels of long-chain MTX polyglutamates through reduced catalytic activity. Furthermore, the FPGS variant was linked with increased relapse risk (P = .044). These findings show a genetic basis for interpatient variability in MTX response and could be used to improve future dosing algorithms.

Epithelioid hemangioendothelioma in children: The European Pediatric Soft Tissue Sarcoma Study Group experience.

The European pediatric Soft tissue sarcoma Study Group analyzed all children with epithelioid hemangioendothelioma prospectively registered in the NRSTS-05 (EUDRACT 2005-001139-31) and in MTS-2008 (NCT00379457) studies: 10 patients with localized and one with metastatic disease. Median age was 14.3 years (range, 9.0-18.8). Local therapy was initial primary surgery in seven cases, and five patients received systemic therapy. No patients received radiotherapy. After a median follow-up of 50 months (range, 6-176) for living patients, nine patients remain alive off therapy and two died. Five-year progression free and overall survivals are, respectively, 77.1% (95% confidence interval [CI]: 34.5-93.9) and 74.1% (95% CI: 28.1-93.0).

Baseline FDG PET/CT in free breathing versus deep inspiration breath-hold for pediatric patients with mediastinal lymphoma.

INTRODUCTION: The prospective TEDDI protocol investigates the feasibility of radiotherapy delivery in deep inspiration breath-hold (DIBH) for pediatric patients. To secure optimal radiotherapy planning, a diagnostic baseline FDG PET/CT in free breathing (FB) and DIBH was acquired. The anatomical changes in the mediastinum and the effect on PET metrics between the two breathing conditions were assessed for pediatric patients with mediastinal lymphoma. MATERIAL AND METHODS: Ten patients aged 5-17 were included and had a PET/CT in FB and DIBH. Metabolic active lymphoma volumes were manually delineated with a visually based segmentation method and the PET metrics were extracted. The anatomical lymphoma, lung and heart volumes were delineated on CT. RESULTS: The lung volume increased while the heart was displaced caudally and separated from the lymphoma in DIBH compared to FB. Both the anatomical and the metabolically active lymphoma volumes appeared different regarding shape and configuration in the two breathing conditions. The image quality of the DIBH PET was equal to the FB PET regarding interpretation and delineation of lymphoma lesions. All PET metrics increased on the DIBH PET compared to the FB PET with the highest increase observed for the maximum standardized uptake value (33%, range 7-56%). CONCLUSION: Diminished respiratory motion together with anatomical changes within the lymphoma increased all PET metrics in DIBH compared to FB. The anatomical changes observed in DIBH compared to FB are expected to reduce radiation doses to the heart and lungs in pediatric patients with mediastinal lymphoma referred for radiotherapy delivery in DIBH and, thereby, reduce their risk of late effects. TRIAL REGISTRATION: The Danish Ethical Committee (H-16035870, approved November 24th 2016), the Danish Data Protection Agency (2012-58-0004, approved 1 January 2017). Registered retrospectively at clinicaltrials.gov (NCT03315546, 20 October 2017).

The risk of late effects following pediatric and adult radiotherapy regimens in Hodgkin lymphoma.

PURPOSE: Adolescent young adults (AYA) with Hodgkin lymphoma (HL) are treated according to either pediatric or adult protocols, however, the best strategy has yet to be established. We describe the AYA patients referred for radiotherapy and quantify the risk of radiation-induced late effects and the corresponding life years lost (LYL) following pediatric and adult regimens. METHODS: Patients ≤24 years irradiated for HL were included. For each patient, organs at risk (OARs) were contoured and dosimetric parameters were extracted. Estimated excess hazard ratios of radiation-induced late effects were calculated from dose-response models and LYL attributable to various late effects were estimated. RESULTS: In total, 77 patients were analyzed (pediatric regimen: 15; adult regimen: 62). Age, clinical stage, and the number of patients enrolled in protocols were significantly different between the groups. Pediatric patients had more advanced disease, which resulted in larger target volumes and higher doses to most OARs, despite a lower prescribed dose compared to adult regimens. LYL estimates were all higher with the pediatric regimens. Total LYL with pediatric and adult treatment regimens were 3.2 years and 2.3 years, respectively. Due to the clinical stage variation and heterogeneity in disease location, a direct comparison of the estimated risks of late effects was only exploratory. CONCLUSION: Pediatric regimens selected patients with more advanced disease to radiotherapy resulting in larger target volumes and higher doses to the OARs. Target volume rather than prescribed dose impacted OAR exposure. Consequently, the estimated risk of radiation-induced late effects and corresponding LYL was increased when compared to adult regimens.

Socioeconomic position and prediagnostic health care contacts in children with cancer in Denmark: a nationwide register study.

BACKGROUND: While underlying mechanisms and pathways of social inequalities in cancer survival have been extensively examined in adults, this is less so for children with cancer. Hypothesized mechanisms include prediagnostic utilization of and navigation through the health care system, which may differ by socioeconomic resources of the families. In this nationwide register-based study we investigated the association between measures of family socioeconomic position in relation to prediagnostic health care contacts and stage of disease at diagnosis in children with cancer in Denmark. METHODS: We identified all children diagnosed with a cancer at ages 0-15 years in 1998-2016 (N = 3043) from the Danish Childhood Cancer Registry. We obtained comprehensive information on measures of socioeconomic position, parental health and prediagnostic contacts to both general practitioners and hospitals 24 months prior to diagnosis from various national registries. We fitted multivariable conditional logistic regression models for the association of family socioeconomic and health-related variables with firstly, frequent health care contacts and secondly, advanced stage. RESULTS: We found higher odds ratios (OR) of frequent both overall and emergency health care contacts in the last 3 months before diagnosis in children from households with short parental education and mixed affiliation to work market, when compared to children with high family socioeconomic position. Further, children of parents with depression or of non-Western origin, respectively, had higher OR for frequent overall and emergency contacts. We found no association between socioeconomic position, parental health and stage of disease. CONCLUSION: Families with socioeconomic disadvantage, non-Western origin or depression more frequently utilize prediagnostic health care services, both generally and in the acute setting, indicating that some disadvantaged families may struggle to navigate the health care system when their child is sick. Reassuringly, this was not reflected in disparities in stage at diagnosis. In order to improve the diagnostic process and potentially reduce health care contacts, attention and support should be given to families with a high number of health care contacts over a short period of time.

Relapse localization in Danish pediatric patients with Hodgkin lymphoma.

BACKGROUND: Pediatric Hodgkin lymphoma (pHL) is highly curable. However, a minority experience relapse and are subjected to toxic salvage regimens. Investigating the patterns of relapse could help to select the patients and/or the involved sites that would benefit from consolidating radiotherapy. MATERIAL AND METHODS: The Danish Childhood Cancer Registry was used to identify children <18 years with relapsed pHL from 1990-2018. The lymphoma volumes involved at diagnosis and at relapse were contoured on the patients' original scans. Rigid image co-registration was used to merge the scans enabling a visual assessment of the anatomical relapse localization relative to the initially involved lymph nodes, and if irradiated, to the radiotherapy field. RESULTS: From 185 patients with pHL, 24 patients with relapse were available for analysis. All patients received combination chemotherapy and seven had consolidating radiotherapy. Relapses exclusively in initially involved sites occurred in 14 patients. Relapses exclusively in new sites were rare and only observed in three irradiated patients. Seven patients relapsed in both initially involved and new sites. The median time to relapse was 6 months (range 2-59 months), however, in-field relapses in irradiated patients occurred later (54 months, range 10-59 months). Neither risk group, initial bulky disease, early response, or metabolic activity seemed to be associated with the site of a later relapse. CONCLUSION: The number of relapses were small, and conclusions regarding the selection of patients for radiotherapy could not be drawn. Relapse exclusively in initially involved sites were the most common, most often in the exact same initially involved lymph nodes. Hence, modern involved site radiotherapy, focusing on the initially involved lymphoma volume and minimizing the radiation doses to normal tissues, should be applied when consolidating radiotherapy is used in patients with pHL.

CNS progression during vinblastine or targeted therapies for high-risk relapsed ALK-positive anaplastic large cell lymphoma: A case series.

Vinblastine and targeted therapies induce remissions in patients with relapsed or progressive anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL). Central nervous system (CNS) prophylaxis often is not included during re-induction in CNS-negative relapse patients. We report on five patients with progressive or early relapsed ALK-positive ALCL who developed CNS progression during re-induction with vinblastine, crizotinib, or brentuximab vedotin given for bridging to allogeneic blood stem cell transplantation. These observations suggest that CNS prophylaxis should be considered in ALCL patients suffering progression during initial therapy who receive re-induction using agents with limited CNS penetration.

Survival and prognostic factors at time of diagnosis in high-grade appendicular osteosarcoma: a 21 year single institution evaluation from east Denmark.

BACKGROUND: Survival of patients with high-grade osteosarcoma (HOS), the most common primary bone cancer, has not improved significantly the last 30 years and the disease remains a major challenge. The purpose of this study is to evaluate survival in relation to prognostic factors at time of diagnosis among patients diagnosed with primary appendicular HOS in East Denmark between 1990 and 2010. MATERIAL AND METHODS: 101 patients (median age = 20 years, female/male ratio = 56/45) diagnosed with primary appendicular high-grade osteosarcoma between 1990 and 2010 were included in this study. Initially, 156 patients diagnosed with osteosarcoma between 1990 and 2010 were identified through the population based Regional Database of Pathology, which covers a population of approximately 2.7 million (east Denmark). 55 patients were excluded due to (A) tumor was low grade (n = 22), (B) located in axial skeleton (n = 18), (C) incorrect diagnosis (n = 11) or (D) biopsy represented a tumor relapse from a former primary osteosarcoma (n = 4). Overall survival was evaluated using the Kaplan-Meier survival analysis and log-rank test. Prognostic factors were analyzed using uni- and multivariate cox-regression method with variables scored equally in the model. p Values <.05 were considered statistically significant. RESULTS: The probability of 5- and 10-year survival was 51% (95% CI: 41-61) and 46% (95% CI: 36-56), respectively. Metastatic stage at diagnosis and tumor size ≥10 cm measured radiologically at the largest diameter were independent prognostic factors for decreased survival with significant increased hazard-risks of 3.5 (95% CI: 1.9-6.5) and 1.97 (95% CI: 1.1-3.6), respectively. DISCUSSION: In this single institution evaluation of primary appendicular HOS we found 5-and 10-year survival rates consistent with international standards for this patient group. Distant metastases and tumor size ≥10 cm at the time of diagnosis were independent prognostic factors for decreased survival in our cohort. These results underline the importance of awareness and early referral from the primary sector.

Hodgkin lymphoma in children, adolescents and young adults - a comparative study of clinical presentation and treatment outcome.

BACKGROUND: Hodgkin lymphoma (HL) treatment protocols for children, adolescents and young adults traditionally differ, but the biological and clinical justification for this remains uncertain. MATERIAL AND METHODS: We compared age-dependent clinical presentation and treatment and outcome for 1072 classical HL patients 0-24 years diagnosed in Denmark (1990-2010) and Sweden (1992-2009) in pediatric (n = 315, Denmark <15 years, Sweden <18 years) or adult departments (n = 757). Distribution of clinical characteristics was assessed with Pearson's chi2-test and Mantel-Haenszel trend test. The Kaplan-Meier method was used for survival analyses. Hazard ratios (HR) were used to compare the different treatment groups and calculated using Cox regression. RESULTS: Children (0-9 years) less often presented with advanced disease than adolescents (10-17 years) and young adults (18-24 years) (stage IIB-IV: children 32% vs. adolescents 50%, and adults 55%; p < .005). No variation in overall survival (OS) was seen between pediatric and adult departments or by country. Danish pediatric patients received radiotherapy (36%) less frequently than Swedish pediatric patients (71%) (p < .0001). Ten-year event-free survival (EFS) was lower among Danish pediatric patients (0-14 years) (0.79; 95% confidence interval (CI) 0.70-0.86) than among Swedish pediatric patients (0-17 years) (0.88; 95% CI 0.83-0.92), HR (1.93; 95% CI 1.08-3.46). A similar pattern was seen between adult patients in the two countries: Denmark 10-year EFS 0.85 (95% CI 0.81-0.88), Sweden 0.88 (95% CI 0.84-0.91), adjusted HR 1.51 (95% CI 1.03-2.22). CONCLUSION: Adolescents and young adults shared similar clinical presentation suggesting a rationale of harmonized treatment for these groups. Both adult and pediatric protocols provided high OS with no significant difference between the departments. The less frequent use of radiotherapy in Danish pediatric patients corresponded to a lower EFS, but comparable OS in all groups confirmed effective rescue strategies for the relapsing patients.

Pediatric cancer families' participation in whole-genome sequencing research in Denmark: Parent perspectives.

With an impending introduction of genome sequencing into paediatric oncology to facilitate personalised medicine, this study examines parent perspectives on participating in whole genome sequencing (WGS) research in the difficult weeks following diagnosis. As an embedded part of Sequencing Tumor and Germline DNA-Implications and National Guidelines (STAGING), a project aiming to implement WGS of all newly diagnosed paediatric cancer patients in Denmark, a parent perspective study was conducted by a clinical geneticist and anthropologist to document pragmatic, social and ethical dilemmas. Following genetic counselling, systematic debriefings were held and the anthropologist carried out in-depth parent interviews (N = 30 parents to 15 patients). Parents were approached about STAGING 2-28 days after diagnosis. The majority of interviewed parents reported that an early approach had been feasible for them, a few found it too early. Participation was explained in terms of altruism and a desire to learn more about why their child had developed cancer. A number of parents openly disagreed about the amount of information they wanted reported back. Enrolment in WGS research around the time of diagnosis is feasible, however, flexibility from researchers is essential. Notwithstanding high participation rates and a tendency to choose full disclosure, caution as regards the consequences of participating in WGS research is warranted.

DNA-thioguanine nucleotide concentration and relapse-free survival during maintenance therapy of childhood acute lymphoblastic leukaemia (NOPHO ALL2008): a prospective substudy of a phase 3 trial.

BACKGROUND: Adjustment of mercaptopurine and methotrexate maintenance therapy of acute lymphoblastic leukaemia by leucocyte count is confounded by natural variations. Cytotoxicity is primarily mediated by DNA-incorporated thioguanine nucleotides (DNA-TGN). The aim of this study was to establish whether DNA-TGN concentrations in blood leucocytes during maintenance therapy are associated with relapse-free survival. METHODS: In this substudy of the NOPHO ALL2008 phase 3 trial done in 23 hospitals in seven European countries (Denmark, Estonia, Finland, Iceland, Lithuania, Norway, and Sweden), we analysed data from centralised and blinded analyses of 6-mercaptopurine and methotrexate metabolites in blood samples from patients with non-high-risk childhood acute lymphoblastic leukaemia. Eligible patients were aged 1·0-17·9 years; had been diagnosed with non-high-risk precursor B-cell or T-cell leukaemia; had been treated according to the Nordic Society of Pediatric Hematology and Oncology ALL2008 protocol; and had reached maintenance therapy in first remission. Maintenance therapy was (mercaptopurine 75 mg/m2 once per day and methotrexate 20 mg/m2 once per week, targeted to a leucocyte count of 1·5-3·0 × 109 cells per L). We measured DNA-TGN and erythrocyte concentrations of TGN nucleotides, methylated mercaptopurine metabolites, and methotrexate polyglutamates. The primary objective was the association of DNA-TGN concentrations and 6-mercaptopurine and methotrexate metabolites with relapse-free survival. The secondary endpoint was the assessment of DNA-TGN concentration and 6-mercaptopurine and methotrexate metabolites during maintenance therapy phase 2. FINDINGS: Between Nov 26, 2008 and June 14, 2016, 1509 patients from the NOPHO ALL2008 study were assessed for eligibility in the DNA-TGN substudy, of which 918 (89%) of 1026 eligible patients had at least one DNA-TGN measurement and were included in the analyses. Median follow-up was 4·6 years (IQR 3·1-6·1). Relapse-free survival was significantly associated with DNA-TGN concentration (adjusted hazard ratio 0·81 per 100 fmol/µg DNA increase, 95% CI 0·67-0·98; p=0·029). In patients with at least five blood samples, erythrocyte concentrations of TGN, methylated mercaptopurine metabolites, and methotrexate polyglutamates were associated with DNA-TGN concentration (all p<0·0001). INTERPRETATION: Our results suggest the need for intervention trials to identify clinically applicable strategies for individualised drug dosing to increase DNA-TGN concentration, and randomised studies to investigate whether such strategies improve cure rates compared with current dose adjustments based on white blood cell counts. FUNDING: Danish Cancer Society, Childhood Cancer Foundation (Denmark), Childhood Cancer Foundation (Sweden), Nordic Cancer Union, Otto Christensen Foundation, University Hospital Rigshospitalet, and Novo Nordic Foundation.

Aetiologic heterogeneity in pediatric Hodgkin lymphoma? Evidence from the Nordic countries, 1978-2010.

BACKGROUND: In epidemiological studies, Hodgkin lymphomas (HL) in children younger than 15 years and HL in adolescents and younger adults age 15-35 years has traditionally been studied separately, under the assumption that HL at age 0-14 constitute a homogeneous entity. However, the continued validity of this research practice in affluent settings may be questioned. Specifically, the boundary at age 15 years may not be epidemiologically justified, and therefore also questionable clinically. We therefore updated and further characterised recent HL incidence patterns among Nordic children. MATERIAL AND METHODS: We obtained HL incidence data in children aged 0-14 years for the period 1978-2010 from the five nationwide Nordic cancer registries. The data were analysed by log-linear and/or a mixture of Poisson regression models. RESULTS: The analyses showed statistically significantly decreasing and increasing HL incidence rates in children younger and older than eight years, respectively during the study period. Statistical modelling suggested that cases in children age 0-6 years constituted a disease entity of its own, whereas cases in older children were more likely to belong to the younger adult HL entity. CONCLUSION: Diverging incidence trends and statistical modelling suggest that HL in children age 0-14 years cannot be assumed to constitute a homogeneous disease entity in affluent settings.

Paediatric CBCT protocols for image-guided radiotherapy; outcome of a survey across SIOP Europe affiliated countries and literature review.

BACKGROUND: Implementation of daily cone-beam CT (CBCT) into clinical practice in paediatric image-guided radiotherapy (IGRT) lags behind compared to adults. Surveys report wide variation in practice for paediatric IGRT and technical information remains unreported. In this study we report on technical settings from applied paediatric CBCT protocols and review the literature for paediatric CBCT protocols. METHODS: From September to October 2022, a survey was conducted among 246 SIOPE-affiliated centres across 35 countries. The survey consisted of 3 parts: 1) baseline information; technical CBCT exposure settings and patient set-up procedure for 2) brain/head, and 3) abdomen. Descriptive statistics was used to summarise current practice. The literature was reviewed systematically with two reviewers obtaining consensus RESULTS: The literature search revealed 22 papers concerning paediatric CBCT protocols. Seven papers focused on dose-optimisation. Responses from 50/246 centres in 25/35 countries were collected: 44/50 treated with photons and 10/50 with protons. In total, 48 brain/head and 53 abdominal protocols were reported. 42/50 centres used kV-CBCT for brain/head and 35/50 for abdomen; daily CBCT was used for brain/head = 28/48 (58%) and abdomen = 33/53 62%. Greater consistency was seen in brain/head protocols (dose range 0.32 - 67.7 mGy) compared to abdominal (dose range 0.27 - 119.7 mGy). CONCLUSION: Although daily CBCT is now widely used in paediatric IGRT, our survey demonstrates a wide range of technical settings, suggesting an unmet need to optimise paediatric IGRT protocols. This is in accordance with the literature. However, there are only few paediatric optimisation studies suggesting that dose reduction is possible while maintaining image quality.

Frontline and Relapsed Rhabdomyosarcoma (FAR-RMS) Clinical Trial: A Report from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG).

The Frontline and Relapsed Rhabdomyosarcoma (FaR-RMS) clinical trial is an overarching, multinational study for children and adults with rhabdomyosarcoma (RMS). The trial, developed by the European Soft Tissue Sarcoma Study Group (EpSSG), incorporates multiple different research questions within a multistage design with a focus on (i) novel regimens for poor prognostic subgroups, (ii) optimal duration of maintenance chemotherapy, and (iii) optimal use of radiotherapy for local control and widespread metastatic disease. Additional sub-studies focusing on biological risk stratification, use of imaging modalities, including [18F]FDG PET-CT and diffusion-weighted MRI imaging (DWI) as prognostic markers, and impact of therapy on quality of life are described. This paper forms part of a Special Issue on rhabdomyosarcoma and outlines the study background, rationale for randomisations and sub-studies, design, and plans for utilisation and dissemination of results.

Ambiguous Expectations of Parent Caregiving for the Child and Adolescent With Cancer at the Hospital and at Home-An Ethnographic Study.

Background: Over the past three decades, complex care and treatment have increasingly become the responsibility of parents as home-based care providers, yet little is known about parents' caregiving experiences when considering the variety of care tasks. It is imperative to gain insight into the challenges parents face when managing treatment and care of their child with cancer to ensure optimal parental support and prior to further expansion of home-based parent caregiving. This study aimed to explore the experiences of children and adolescents with cancer, who had received treatment through a portable infusion pump, and their parents in managing different care tasks. It is the first study and forms the basis of the research project INTACTatHome, that develops and tests interventions of home-based intravenous anti-cancer treatment. Methods: Ethnographic fieldwork comprising participant observation and semi-structured interviewing analyzed using qualitative thematic analysis. Thirteen families participated in the study. Results: Three main themes were identified: (1) being a "mini-nurse"; (2) dividing care; and (3) managing anxiety and fear, each based on separate sub-themes. These themes were bound together by an overarching theme: "Ambiguous expectations of parent caregiving." Discussion: This study contributes to a deeper understanding of the varying experiences of children and adolescents and their parents in managing different care tasks for a child or adolescent with cancer. It underscores the need to establish clear expectations of parents as caregivers throughout the cancer treatment trajectory. This perspective is crucial when developing and implementing future home-based care services.

Detection of circulating tumor-derived material in peripheral blood of pediatric sarcoma patients: A systematic review.

BACKGROUND: Detection of circulating tumor-derived material (cTM) in the peripheral blood (PB) of cancer patients has been shown to be useful in early diagnosis, prediction of prognosis, and disease monitoring. However, it has not yet been thoroughly evaluated for pediatric sarcoma patients. METHODS: We searched the PubMed and EMBASE databases for studies reporting the detection of circulating tumor cells, circulating tumor DNA, and circulating RNA in PB of pediatric sarcoma patients. Data on performance in identifying cTM and its applicability in diagnosis, and evaluation of tumor characteristics, prognostic factors, and treatment response was extracted from publications. RESULTS: A total of 79 studies were assigned for the present systematic review, including detection of circulating tumor cells (116 patients), circulating tumor DNA (716 patients), and circulating RNA (2887 patients). Circulating tumor cells were detected in 76% of patients. Circulating DNA was detected in 63% by targeted NGS, 66% by shallow WGS, and 79% by digital droplet PCR. Circulating RNA was detected in 37% of patients. CONCLUSION: Of the cTM from Ewing's sarcoma and rhabdomyosarcoma ctDNA proved to be the best target for clinical application including diagnosis, tumor characterization, prognosis, and monitoring of disease progression and treatment response. For osteosarcoma the most promising targets are copy number alterations or patient specific micro RNAs, however, further investigations are needed to obtain consensus on clinical utility.

Protocol for a prospective, longitudinal study of cognitive impairment in young patients with cancer: a multidisciplinary neuroscience approach (MyBrain).

INTRODUCTION: The aim of this research is to investigate young cancer patients' cognitive functioning and the underlying neurobiological mechanisms when cognitive functions are impaired. The MyBrain protocol is a multidisciplinary study that investigates cancer-related cognitive impairment in children, adolescents and young adults, combining neuropsychology, cognitive neuroscience and cellular neuroscience. The study is exploratory with a wide focus on trajectories of cognitive functions from diagnosis to the end of treatment and into survivorship. METHODS AND ANALYSIS: Prospective longitudinal study including patients diagnosed with non-brain cancers at age 7-29 years. Each patient is paired with a control matched on age and social circle. PRIMARY OBJECTIVE: Evaluation of neurocognitive function over time. SECONDARY OBJECTIVES: Evaluation of self-perceived quality of life and fatigue, P300 in an electroencephalography (EEG) oddball paradigm, power spectrum in resting state EEG, serum and cerebrospinal fluid levels of biomarkers of neuronal damage, neuroplasticity, proinflammatory and anti-inflammatory markers and their association with cognitive function. ETHICS AND DISSEMINATION: The study is approved by the Regional Ethics Committee for the Capital Region of Denmark (no. H-21028495), and the Danish Data Protection Agency (no. P-2021-473). Results are expected to guide future interventions to prevent brain damage and support patients with cognitive difficulties. TRIAL REGISTRATION NUMBER: The article is registered at clinicaltrials.gov NCT05840575 (https://clinicaltrials.gov/ct2/show/NCT05840575).