CPT-SIOP registry: evaluation of risk factors for disease progression in pediatric choroid plexus papilloma.

Purpose: Choroid plexus papilloma (CPP) and atypical choroid plexus papilloma (aCPP) have excellent outcomes. However, some CPP/aCPP relapse and may qualify for postoperative adjuvant treatment.

Methods: German patients from the International CPT-SIOP Registry diagnosed with CPP/aCPP between 2011 and 2023 were included and analysed according to initial staging (postoperative residual tumor [R+], metastases [M+]), biology, postoperative treatment strategy and outcome.

Late toxicity after upper abdominal radiotherapy in pediatric Wilms tumor and neuroblastoma survivors. A systematic review on behalf of SIOPEN and SIOP-RTSG.

Background: Radiotherapy plays a crucial role in the multimodal treatment of Wilms tumor and neuroblastoma subtypes with an increased risk of locoregional failure. Unfortunately, radiotherapy can be associated with late toxicities in survivors. This systematic review provides an overview of the quality of evidence related to late effects following upper abdominal radiotherapy in survivors of Wilms tumor and neuroblastoma.

European practice on neurovascular late effects after pediatric radiotherapy: considerations on dose planning and follow-up - a HARMONIC/SIOPE ROWG survey.

Background And Purpose: The risk of developing neurovascular late effects after radiotherapy is an area of concern when treating pediatric brain tumor patients. However, knowledge is sparse regarding best practice for clinical management during the radiotherapy (RT) planning process and follow-up examinations. This study therefore aimed at mapping how the risk of neurovascular late effects is considered for pediatric brain or skull base tumor patients treated with radiotherapy in Europe.

Systematic review of MRI alterations in the brain following proton and photon radiation therapy: Towards a uniform European Particle Therapy Network (EPTN) definition.

Magnetic resonance imaging (MRI) often demonstrates alterations following cranial radiotherapy (RT), which may result in clinical symptoms and diagnostic uncertainty, and thus potentially impact treatment decisions. The potential differences in MRI alterations after proton and photon RT, has raised concerns regarding the relative biological effectiveness of proton therapy. To provide an overview of MRI alterations in the brain post-RT and to explore differences between photon and proton RT, a systematic review adhering to the PRISMA guidelines was conducted, focusing on the assessment methods and definitions across studies.

GPOH Guidelines for Diagnosis and First-line Treatment of Patients with Neuroblastic Tumors, update 2025.

The clinical course of neuroblastoma is more heterogeneous than any other malignant disease. Many low-risk patients experience regression after limited or even no chemotherapy. However, more than half of high-risk patients die from disease despite intensive multimodal treatment.

Twenty Years of the Paediatric Radiation Oncology Society.

In 2005, the Paediatric Radiation Oncology Society (PROS), a multi-professional association to promote radiotherapy for children and young people, was created. Its mission has been to educate those involved in this field, and to improve the standards of radiation oncology care for children, adolescents, and young adults across the globe, not least in less privileged settings where the majority of the world's children, and most with cancer, live. Through regular congresses, and joint meetings with the International Society of Paediatric Oncology (SIOP), PROS has facilitated a focus on this treatment modality, and advocated on behalf of those who might benefit from it.

Genetic predisposition in sarcomas: clinical implications and management.

Unlabelled: Recent studies indicate up to 20% of sarcomas may be associated with predisposition genes, and this number will probably increase as genetic testing becomes more available. Evidence on the management of patients with sarcoma and genetic predisposition remains, however, scarce. This review compiles available research on genetic predisposition syndromes associated with sarcoma and sarcoma treatment within such syndromes, addressing key gaps in knowledge.

Evaluation of OPTOS wide-field fundus image projections for radiotherapy planning of uveal melanoma.

Purpose: To investigate the relationship between the stereographic and azimuthal equidistant projection (AEP) of the human retina for radiotherapy planning with OPTOS optomap wide-field fundus images (Optos, UK). Further, the geometric accuracy of an OPTOS fundus image is quantified.

Methods: The fundamental relationship between both projection modes was applied to transform images acquired with an OPTOS Silverstone camera to the azimuthal equidistant projection using MATLAB.

Recurrence patterns in pediatric intracranial ependymal neoplasm: a systematic imaging work-up.

Purpose: Currently, the different types of ependymal neoplasm (EPN) are defined by anatomical localization and genetics. This retrospective multicenter study aimed to analyze the imaging patterns of both local and distant recurrences in supratentorial (ST) and posterior fossa (PF) EPN.

Methods: We exclusively evaluated patients with recurrent EPN.

Alpha/beta values in pediatric medulloblastoma: implications for tailored approaches in radiation oncology.

Background: Medulloblastoma is the most common malignant pediatric brain tumor, typically treated with normofractionated craniospinal irradiation (CSI) with an additional boost over about 6 weeks in children older than 3 years. This study investigates the sensitivity of pediatric medulloblastoma cell lines to different radiation fractionation schedules. While extensively studied in adult tumors, these ratios remain unknown in pediatric cases due to the rarity of the disease.

Primary Mediastinal Ewing's Sarcoma: Post Hoc Analysis from Two International Multicenter Prospective Randomized Trials.

Objective: Ewing sarcoma (EWS) of the mediastinum is extremely rare, with only a few cases reported in the literature. We aimed to gain a better understanding of primary mediastinal EWS, describing patients treated within two international, multicenter, prospective, randomized EWS trials.

Methods: Data from patients with primary mediastinal EWS were retrieved from the database of the EURO-E.

The sarcoma ring trial: a case-based analysis of inter-center agreement across 21 German-speaking sarcoma centers.

Purpose: The management of soft tissue sarcoma (STS) at reference centers with specialized multidisciplinary tumor boards (MTB) improves patient survival. The German Cancer Society (DKG) certifies sarcoma centers in German-speaking countries, promoting high standards of care. This study investigated the variability in treatment recommendations for localized STS across different German-speaking tertiary sarcoma centers.

Impact of molecular classification on prognosis in children and adolescents with spinal ependymoma: Results from the HIT-MED database.

Background: Ependymomas of the spinal cord are rare among children and adolescents, and the individual risk of disease progression is difficult to predict. This study aims to evaluate the prognostic impact of molecular typing on pediatric spinal cord ependymomas.

Methods: Eighty-three patients with spinal ependymomas ≤22 years registered in the HIT-MED database (German brain tumor registry for children, adolescents, and adults with medulloblastoma, ependymoma, pineoblastoma, and CNS-primitive neuroectodermal tumors) between 1992 and 2022 were included.

Treatment of Pediatric, Adolescent, and Young Adult Patients With Fusion-Positive Alveolar Rhabdomyosarcoma Infiltrating Regional Lymph Nodes in the European CWS-2002P and RMS 2005 Studies and the Soft Tissue Sarcoma Registry.

Background: Patients with alveolar rhabdomyosarcoma (ARMS) with regional lymph node involvement (N1) are defined as "very-high-risk rhabdomyosarcoma" in Europe. Different chemotherapy regimens were used in European study protocols.

Methods: Patients with FOXO1 fusion-positive N1 ARMS registered in the CWS-2002P study, the EpSSG RMS 2005 study, and SoTiSaR were retrospectively investigated.

Dose distributions of proton therapy plans are robust against lowering the resolution of CTs combined with increasing noise.

Background: Treatment planning in radiation therapy (RT) is performed on image sets acquired with commercial x-ray computed tomography (CT) scanners. Considering an increased frequency of verification scans for adaptive RT and the advent of alternatives to x-ray CTs, there is a need to review the requirements for image sets used in RT planning.

Purpose: This study aims to derive the required image quality (IQ) for the computation of the dose distribution in proton therapy (PT) regarding spatial resolution and the combination of spatial resolution and noise.

Proof-of-principle of 3D-printed track-end detectors for dosimetry in proton therapy.

Background: Dosimetric equipment in particle therapy (PT) is associated with high costs. There is a lack of versatile, tissue-equivalent detectors suitable for in-vivo dosimetry. Faraday-cup (FC) type detectors are sensitive to stopped protons, that is, to track-ends (TEs).

ESTRO-EANO guideline on target delineation and radiotherapy for IDH-mutant WHO CNS grade 2 and 3 diffuse glioma.

Purpose: This guideline will discuss radiotherapeutic management of IDH-mutant grade 2 and grade 3 diffuse glioma, using the latest 2021 WHO (5th) classification of brain tumours focusing on: imaging modalities, tumour volume delineation, irradiation dose and fractionation.

Methods: The ESTRO Guidelines Committee, CNS subgroup, nominated 15 European experts who identified questions for this guideline. Four working groups were established addressing specific questions concerning imaging, target volume delineation, radiation techniques and fractionation.

Distinct relapse pattern across molecular ependymoma types.

Background: Ependymoma (EPN) is not a uniform disease but represents different disease types with biological and clinical heterogeneity. However, the pattern of when and where different types of EPN relapse is not yet comprehensively described.

Methods: We assembled 269 relapsed intracranial EPN from pediatric (n = 233) and adult (n = 36) patients from European and Northern American cohorts and correlated DNA methylation patterns and copy-number alterations with clinical information.

Linear energy transfer dependent variation in viability and proliferation along the Bragg peak curve in sarcoma and normal tissue cells.

The energy deposition of photons and protons differs. It depends on the position in the proton Bragg peak (BP) and the linear energy transfer (LET) leading to a variable relative biological effectiveness (RBE). Here, we investigate LET dependent alterations on metabolic viability and proliferation of sarcoma and endothelium cell lines following proton irradiation in comparison to photon exposure.

A deep-learning-based surrogate model for Monte-Carlo simulations of the linear energy transfer in primary brain tumor patients treated with proton-beam radiotherapy.

This study explores the use of neural networks (NNs) as surrogate models for Monte-Carlo (MC) simulations in predicting the dose-averaged linear energy transfer (LET) of protons in proton-beam therapy based on the planned dose distribution and patient anatomy in the form of computed tomography (CT) images. As LETis associated with variability in the relative biological effectiveness (RBE) of protons, we also evaluate the implications of using NN predictions for normal tissue complication probability (NTCP) models within a variable-RBE context.The predictive performance of three-dimensional NN architectures was evaluated using five-fold cross-validation on a cohort of brain tumor patients (= 151).

Clinical practice in European centres treating paediatric posterior fossa tumours with pencil beam scanning proton therapy.

Background And Purpose: As no guidelines for pencil beam scanning (PBS) proton therapy (PT) of paediatric posterior fossa (PF) tumours exist to date, this study investigated planning techniques across European PT centres, with special considerations for brainstem and spinal cord sparing.

Materials And Methods: A survey and a treatment planning comparison were initiated across nineteen European PBS-PT centres treating paediatric patients. The survey assessed all aspects of the treatment chain, including but not limited to delineations, dose constraints and treatment planning.

Radiotherapy for Recurrent Medulloblastoma in Children and Adolescents: Survival after Re-Irradiation and First-Time Irradiation.

Background: Radiotherapy (RT) involving craniospinal irradiation (CSI) is important in the initial treatment of medulloblastoma. At recurrence, the re-irradiation options are limited and associated with severe side-effects.

Methods: For pre-irradiated patients, patients with re-irradiation (RT2) were matched by sex, histology, time to recurrence, disease status and treatment at recurrence to patients without RT2.