Germline analysis of an international cohort of pediatric diffuse midline glioma patients.

Background: Factors that drive the development of diffuse midline gliomas (DMG) are unknown. Our study aimed to determine the prevalence of pathogenic/likely pathogenic (P/LP) germline variants in pediatric patients with DMG.

Methods: We assembled an international cohort of 252 pediatric patients with DMG, including diffuse intrinsic pontine glioma (n=153), with germline whole genome or whole exome sequencing.

Evaluation of plan quality, safety, and toxicity of brachytherapy for locally advanced cervical cancer in an Australian setting following changes in prescription and applicator design.

Introduction: Chemoradiotherapy with MRI-guided brachytherapy boosts is the standard of care for locally advanced cervical cancer. Data from the RetroEMBRACE and EMBRACE I trials provide dose-response curves for target volumes and OAR. This study evaluated plan quality, safety and toxicity following escalation of the CTV_HR D90 prescription from 80-90 Gy to 85-95 Gy for two different applicator designs.

Quality assurance and other challenges in paediatric radiotherapy: Accurate delivery of craniospinal radiotherapy.

Introduction: Cranio-spinal radiotherapy (CSI) is used to treat central nervous system malignancies in paediatric, adolescent/young adult (AYA), and adult patients. Its delivery in the paediatric/AYA population is particularly challenging across different age groups. This study aims to assess the setup variations and dosimetric impact of CSI in paediatric and AYA patients.

Improving plan quality in cervical brachytherapy using a simple knowledge-based prediction tool for OAR dose (D2cm).

Purpose: Toxicity from cervical brachytherapy has been demonstrated to correlate with the D2cm of the bladder, rectum, and bowel. This suggests a simplified version of knowledge-based planning investigating the relationship of the overlap distance for 2cm and the D2cm from planning may be possible. This work demonstrates the feasibility of simple knowledge-based planning to predict the D2cm, detect suboptimal plans, and improve plan quality.

Quality improvement in paediatric radiation oncology through peer review.

Introduction: Around 300 children in Australia and New Zealand (ANZ) undergo a course of radiation treatment (RT) each year. A fortnightly videoconference for radiation oncologists managing children started in 2013. We conducted an audit of the videoconference to assess its influence on the care of children who receive RT in ANZ.

Changes in Brain Metastasis During Radiosurgical Planning.

Purpose: To determine whether there are any changes in brain metastases or resection cavity volumes between planning magnetic resonance imaging (MRI) and radiosurgery (RS) treatment and whether these led to a change in management or alteration in the RS plan.

Methods And Materials: Patients undergoing RS for brain metastasis or tumor resection cavities had a standardized planning MRI (MRI-1) performed and a repeat verification MRI (MRI-2) 24 hours before RS. Any change in management, including replanning based on MRI-2, was recorded.

Dosimetric comparison of volumetric modulated arc therapy and linear accelerator-based radiosurgery for the treatment of one to four brain metastases.

Introduction: The purpose of this study is to compare and evaluate volumetric modulated arc therapy (VMAT) and linear accelerator-based radiosurgery (Linac RS) for the treatment of one to four brain metastases.

Methods: Radiotherapy plans for 10 patients with 1 to 4 brain metastases that were planned and treated using conventional Linac RS were replanned using a mono-isocentric VMAT technique using two to four arcs. The same doses, target volumes and organs at risk (OAR) were used in both plans.