ESTRO 2025 - Abstract Book

Brachytherapy - Gastro-intestinal, paediatric brachytherapy, miscellaneous

S192

ESTRO 2025

Dammerer, D., Neugebauer, J., Braito, M., Wagner, M., Neubauer, M., Moser, L., Süß, M., Liebensteiner, M., & Putzer, D. (2023). Midterm Results of High-Dose-Rate Intraoperative Brachytherapy in the Treatment of Soft Tissue Sarcomas. Cancers , 15 (10), 2854. https://doi.org/10.3390/cancers15102854 Najafi, A., Saberi, S., Kazemian, A., Jalalpour, P., & Azarsina, S. (2022). A Comparative Study of Soft Tissue Sarcomas of the Extremities; Brachytherapy versus Radiotherapy. Journal Of Orthopedic And Spine Trauma. https://doi.org/10.18502/jost.v7i4.8859

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Digital Poster Paediatric brachytherapy: Our experience in an adult hospital

Laura Martínez Ávila 1 , Marc Juárez Lozano 1 , Dina Najjari Jamal 1 , Pablo Araguas Mora 1 , Andrea Slocker Escarpa 1 , Ruth Gracia Lucio 2 , Francisco Jose Pino Sorroche 2 , Pilar Fernández López 1 , Monica Ramos Albiac 3 , Gabriela Guillen Burrieza 4 , Cristina Gutiérrez Miguélez 1 1 Oncología Radioterápica, Institut Català Oncologia - ICO L'Hospitalet, L'Hospitalet de Llobregat, Spain. 2 Física Médica y Protección Radiológica, Institut Català Oncologia - ICO L'Hospitalet, L'Hospitalet de Llobregat, Spain. 3 Oncología Radioterápica, Hospital Universitari Vall d'Hebron, Barcelona, Spain. 4 Cirugía Pediátrica, Hospital Universitari Vall d'Hebron, Barcelona, Spain

Purpose/Objective:

Brachytherapy is an effective treatment for selected paediatric patients. Developing and sustaining expertise in paediatric brachytherapy is challenging for individual centers because of a relatively small number of cases. The aim of this study is to describe our workflow in paediatric brachytherapy and analyze our experience.

Material/Methods:

From January 2009 until November 2024, 12 children have received interstitial brachytherapy in our unit - which normally only treat adult patients. For the implantation process, the brachytherapist attended to the paediatric hospital and was helped by paediatric surgeons to place the catheters in the tumoral bed after the surgical resection was done. After 24-48 hours of recovery, the child was admitted in our department to deliver the HDR brachytherapy treatment. A retrospective analysis was conducted. We included clinical data (age, sex, location, pathology report, follow up) as well as treatment (number of catheters used, treatment volume, total dose received, fractionation and modality) and late toxicity, defined as 1 year after completing brachytherapy. Descriptive statistical methods were applied. Overall 12 patients were included in the analysis. Mean age was 6.32 years (SD 5.79). The most common location was bladder (66.7%), followed by soft-tissue sarcoma (paravertebral, glutes and mandible) and the most prevalent histology was rhabdomyosarcoma (75%). Mean total dose was 34.7 Gy and the 66.7% of patients received a scheme of 40 Gy in 10 fractions with 4 Gy per fraction twice a day. Median number of catheters used were 4.42 (IQR 3.75 5.25) with a mean treated volume of 41 cc (range 8.37-80.2). With a median follow-up of 72.5 months (IQR 11.1-152), all patients are alive. Only two patients (16.7%) presented local relapse during first year of follow-up after brachytherapy treatment; a 13 years old patient who received brachytherapy such a salvage treatment because of a previous relapse and a 16 years old patient who had a very large tumor (8.2x10x11.4cm, LLxCCxAP, 440cc) with bladder, prostate and pelvis invasion. Late toxicity G1-2 was observed in three patients and only one presented G3 proctitis. Results: