S862
Clinical - Mixed sites & palliation
ESTRO 2026
cases. Forty-three lesions (20.1%) showed no response.Treatment response did not significantly correlate with primary tumor type, patient age, sex, ECOG performance status, or metastatic tumor volume.Response onset was rapid, occurring immediately in 74% of cases, within one month in 16%, and within three months in 10%.Only two fractures were reported among the 214 treated lesions, both occurring in large-volume metastases during long- term follow-up. Conclusion: Although this is a retrospective study, the results suggest that SBRT is effective and safe for managing pain associated with bone metastases, with a low fracture rate observed. References: Chow E, Zeng L, Salvo N, et al. Update on the systematic review of palliative radiotherapy trials for bone metastases. Clin Oncol R Coll Radiol G B 2012; 24:112–24. Wu JS-Y, Wong R, Johnston M, et al. Meta- analysis of dose-fractionation radiotherapy trials for the palliation of painful bone metastases. Int J Radiat Oncol Biol Phys 2003Mercier C, Billiet C, Ost P, et al. Dose-Escalated Stereotactic Versus Conventional Radiotherapy for Painful Bone Metastases (ROBOMET): a multicenter, patient-blinded randomized clinical trial. J Clin Oncol 2025; 0:JCO-24–01447. doi: 10.1200/JCO- 24-01447. Keywords: Bone metastases, pain, SBRT Radiobiological dose and treatment duration influence pain relief and sensory outcomes in CyberKnife radiosurgery for trigeminal neuralgia Evaggelos Pantelis 1,2 , Argyris Moutsatsos 2 , Anastasia Stergioula 2 , David J. Park 3 , Ahed Kattaa 4 , Cynthia Chuang 5 , Steven Chang 4 , Livia Corinna Bianchi 6 , Irene Radaelli 6 , Anna Stefania Martinotti 6 , Giancarlo Beltramo 6 , Guliz Acker 7 , Diana Sladek 7 , Carolin Senger 7 , Antonio Pontoriero 8 , Eleonora Trifiletti 8 , Alfredo Conti 9 , Pantaleo Romanelli 6,10 1 Medical Physics Lab., School of Medicine, National and Kapodistrian University of Athens, Athens, Greece. 2 CyberKnife Radiosurgery Department, Iatropolis Clinic, Athens, Greece. 3 Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, USA. 4 Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, Greece. 5 Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, USA. 6 CyberKnife Center, Centro Diagnostico Italiano (CDI), Milan, Italy. 7 Cyberknife Center, Department of Radiation Oncology and Radiotherapy, Charite, Berlin, Germany. 8 Department Digital Poster 602
of Biomedical, Dental and Morphological and Functional Image Sciences, University of Messina, Messina, Italy. 9 Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy. 10 Neurosurgery and Stereotactic Radiosurgery, The Renaissance Institute, Winter Park, USA Purpose/Objective: This study aimed to characterize the variability in treatment delivery time in CyberKnife radiosurgery (CKRS) for Trigeminal Neuralgia (TN) and investigate their relationship with clinical outcomes using time- dependent radiobiological parameters. Material/Methods: Demographic, clinical, and treatment data from
patients who underwent CKRS for TN were retrospectively extracted from the database.
Treatment delivery timeline and planning parameters were obtained from system-generated XML files. For each case, time-resolved dose and dose-rate distributions were reconstructed on a beam-by-beam basis for every voxel within the target. Biological Effective Dose (BED) distributions accounting for sublethal repair ( α / β = 2.47Gy) were calculated. Follow- up data were collected from medical records and telephone interviews. Pain intensity and facial numbness were assessed using the Barrow Neurological Institute (BNI) Pain and Numbness Scales, respectively. Recurrence was defined as a bothering and prolonged worsening of pain relative to the maximum level of response. Results: A total of 608 patients were analyzed (Table 1). Prior to CKRS, 89% of patients presented with BNI IV-V pain; 87% reported no facial numbness, 12% mild non-
bothersome numbness, and 1% bothersome numbness. Treatments were delivered using
CyberKnife systems operating at 800 or 1000 MU/min. All treatment plans utilized the 5-mm fixed collimator and prescribed a median marginal dose of 60 Gy.Table 1. Statistical analysis of the patient cohort
Made with FlippingBook - Share PDF online