ESTRO 2025 - Abstract Book

S1631

Clinical – äediatric tumours

ESTRO 2025

Results: Median age was 8 years (range: 1 – 49 yrs; 88.4% were less than 20 yrs). The commonest histology was ERMS (64.7%) followed by ARMS (32%). Site of disease was parameningeal (69.6%), orbit (16.7%) and other non parameningeal sites (13.7%). Mean tumor size was 4.6 cm (range: 1–11 cm). Regional nodes were positive in 31.4%. Majority (87.2%) had IRS Gp III disease. Majority (72.4%) received local therapy within 9 weeks of induction chemotherapy. Definitive radiotherapy was the local treatment in 143 (80.3%). Median radiotherapy dose was 50.4Gy (range: 36 - 59.4Gy). After a median follow up of 31 mths (range: 2 –118 mths) the local control (LC), disease free survival (DFS) and overall survival (OS) at 5 yrs were 61.3%, 52.6% and 62.2% respectively. Patients with orbital disease had superior LC compared to other sites (78.9% vs 63.5%). LC was superior in pts with tumors <5cm (62.5% vs 48.8%), without intracranial extension (66.1% vs 48.4%) and Non parameningeal sites (75.3% vs 58.1%). Grade 3 acute skin and mucosal toxicities were seen in 10%. Late toxicities included cataract, xerostomia, dental caries and subcutaneous fibrosis in 14.7%, 8.8%, 7.8% and 2% respectively.

Conclusion: Tumor size >5cm, parameningeal site and intracranial extension of disease results in inferior disease control. Radiotherapy dose escalation may be considered for patients with large volume disease > 5cm.

Keywords: Rhabdomyosarcoma, Outcomes, Prognostic factors

2559

Digital Poster Optimizing the Care of Adolescents and Young Adults (AYA) in Radiotherapy: A Study at Gustave Roussy Noura Sellami 1 , valentine Martin 1 , Stéphanie Bolle 1 , Nathalie Gaspard 2 , frederic dhermain 1 1 radiation therapy, Gustave Roussy, villejuif, France. 2 pediatric oncology, Gustave Roussy, villejuif, France Purpose/Objective: The radiotherapy department at Gustave Roussy plays a pivotal role in treating Adolescents and Young Adults (AYA), a group comprising 15% of radiotherapy (RTE) patients. They are a heterogeneous population with specific needs often overlooked compared to pediatric care. Despite the existence of specialized pediatric and adult oncology units, there are significant gaps in AYA care, particularly in radiotherapy. This study, prompted by firsthand clinical experiences, aims to evaluate current practices, identify challenges, and propose actionable improvements to optimize AYA care in radiotherapy. Material/Methods: The study involved medical and paramedical staff at Gustave Roussy's radiotherapy department, including doctors, technicians, secretaries, and others. A secure, anonymous online survey with 40 questions, designed via Eval&GO, was distributed to 100 staff members. Questions addressed demographics, experience with AYA patients, barriers to treatment, and suggestions for improvement. Data analysis combined descriptive statistics and visualizations. Results: The response rate was 46%, with a 100% completion rate. Most participants had experience treating at least one AYA, though only a few (3 out of 46) had received specific AYA-related training. While 76% were aware of Gustave Roussy's AYA unit, 21.7% were unaware of its existence. Challenges highlighted included: • Communication : Tailoring discussions, addressing taboos, and utilizing appropriate tools. • Scheduling : Flexibility in appointments and accommodating school or work commitments. • Support Structures : Lack of awareness of existing specialized resources and the need for better coordination.