ESTRO 2025 - Abstract Book

S14

Invited Speaker

ESTRO 2025

plexus—a complex network of nerves near the aorta— is associated with poor quality of life, decreased physical independence, increased rates of depression, and shortened survival. In many patients, the high doses of opiods required to overcome the pain are associated with significant side effects. Celiac Plexus Radiosurgery was developed to be a transformative, non-invasive solution, delivering a high single-dose of radiation precisely targeted at the peri-aortic region where celiac plexus is located (Jacobson et al., 2022, BMJ Open). The innovation of Celiac Plexus Radiosurgery lies in its novel adaptation of radiosurgical technology, traditionally reserved for tumor ablation, to disrupt neural pain transmission pathways. Unlike invasive procedures such as neurolytic celiac plexus blocks, which carry procedural risks and often result in inconsistent outcomes, this method leverages the pinpoint accuracy of modern radiosurgery to comprehensively and safely target the celiac plexus while sparing surrounding tissues. The single-session delivery further enhances its appeal, minimizing the treatment burden on patients and not requiring an interruption to systemic treatment regimens. Finally, a novel approach towards treatment planning, utilizing several planning target regions with prescription dose depending on the distance from organs-at-risk, allows for safe treatment delivery despite a very high, ablative dose being delivered in close proximity to small bowel. In a recently published multicenter international phase II clinical trial which included 125 treated patients (Lawrence et al., Lancet Oncology, 2024), Celiac Plexus Radiosurgery demonstrated clinical efficacy. At three weeks post treatment, over half of the evaluable patients reported pain relief, with some achieving complete resolution of symptoms. This effect led to a significant reduction in analgesics uptake at six weeks. The treatment’s safety profile proved manageable, considering the palliative advanced-disease setting, with 11 serious adverse events of grade 3 or worse recorded in total, two of which were considered to be probably associated with treatment (abdominal pain and nausea). The method’s recognition in international guidelines underscores its potential as a standard of care. We continue research in this direction, including efforts to improve and facilitate clinical implementation (Miszczyk et al., 2024, Contemp Oncol). • Jacobson G, Fluss R, Dany-BenShushan A, et al. Coeliac plexus radiosurgery for pain management in patients with advanced cancer : study protocol for a phase II clinical trial. BMJ Open. 2022;12(3):e050169. doi:10.1136/bmjopen 2021-050169 • Lawrence YR, Miszczyk M, Dawson LA, et al. Celiac plexus radiosurgery for pain management in advanced cancer: a multicentre, single-arm, phase 2 trial. Lancet Oncol. 2024;25(8):1070-1079. doi:10.1016/S1470-2045(24)00223-7 • Miszczyk M, Malec-Milewska M, Suleja A, et al. Celiac plexus radiosurgery - an introduction to the method and a practical manual. Contemp Oncol (Pozn). 2024;28(3):242-244. doi:10.5114/wo.2024.144315

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Speaker Abstracts RTT roles for single fraction SBRT: Game changer? Claudio Votta, Lorenzo Placidi, Luca Boldrini Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Rome, Italy

Abstract:

The introduction of single-fraction stereotactic body radiotherapy (SBRT) is redefining the landscape of radiotherapy (RT), bringing it closer to a surgical-like approach. This paradigm shift has significant implications for radiation therapy technologists (RTTs), requiring the development of new skills, adaptation to hybrid systems, and an optimized clinical workflow. Compared to conventional fractionated treatments, single-fraction SBRT demands an unprecedented level of precision, as any deviation from the intended treatment plan can have a direct impact on patient outcomes.