ESTRO 2025 - Abstract Book

S651

Clinical - CNS

ESTRO 2025

Results: Forty-one patients (20 low-risk and 21 high-risk) were analyzed. The median age was 66 years (interquartile range [IQR]: 59-76), 66% were female, 56% had at KPS of ≥90, and 51% had a high school/equivalent or less level of education, 46% were evaluated in Spanish, and 93% had subsequent systemic therapy, without any significant differences between the cohorts (p>0.05). At the 3-month NCA evaluation, ND rates on ≥1 neurocognitive test were significantly higher for the high-risk cohort (16/21, 76%) compared to the low-risk cohort (8/20, 40%, p=0.019). For the entire cohort, learning and memory was the most affected domain (13/41, 32%), followed by attention and information processing speed (8/41, 20%), executive function (7/41, 17%), visual-motor speed (3/41, 7%), and verbal fluency (3/41, 7%). Most participants reported participating in the neurocognitive program enhanced discussions with their clinicians (71.8%), helped them feel more in control of their own care (74.4%), and 94.5% recommended the system to other similar patients. Conclusion: This novel tablet-based NCA battery effectively distinguished ND among patients undergoing subsequent courses of SRS/FSRS, indicating that disease progression in the brain and subsequent treatments are impactful to a patient’s neurocognitive function. Ultimately, such tools should be implemented in the clinic given the modest rates of ND as well as the patient-perceived importance of such metrics. Mini-Oral Planned interim analysis of PREOP-2 randomised trial (NCT05124236): low toxicity and high feasibility of preoperative SRS for brain metastases. Susanne J Rogers 1 , Oliver Blanck 2,3 , Olaf Wittenstein 2,3 , Hajrullah Ahmeti 4 , Ekin Ermis 5 , Irena Zubak 6 , Brigitta G Baumert 7 , Christian Zweifel 8 , Danijela Minasch 9 , Johannes Kerschbaumer 10 , Sonja Schwenne 1 , Miriam Weiss 11 , Lukas Andereggen 11,12 , Christian Musahl 4 , Gerrit A Schubert 11,13 , Oliver Riesterer 1 1 Radiation Oncology Centre Mittelland, Kantonsspital Aarau, Aarau, Switzerland. 2 Department of Radiation Oncology, University Medical Center Schleswig Holstein, Campus Kiel, Kiel, Germany. 3 Department of Radiosurgery, Saphir Radiosurgery Center Northern Germany, Kiel, Germany. 4 Department of Neurosurgery, University Medical Center Schleswig Holstein, Campus Kiel, Kiel, Germany. 5 Department of Radiation Oncology, Bern University Hospital, University of Bern, Bern, Switzerland. 6 Department of Neurosurgery, Bern University Hospital, University of Bern, Bern, Switzerland. 7 Department of Radiation Oncology, Kantonsspital Graubünden, Chur, Switzerland. 8 Department of Neurosurgery, Kantonsspital Graubünden, Chur, Switzerland. 9 niversity Clinic of Radiotherapy, Medical University of Innsbruck, Innsbruck, Austria. 10 University Clinic for Neurosurgery, Medical University of Innsbruck, Innsbruck, Austria. 11 Department of Neurosurgery, Kantonsspital Aarau, Aarau, Switzerland. 12 Faculty of Medicine, Medical University of Innsbruck, Innsbruck, Austria. 13 Department of Neurosurgery, RWTH Aachen University, Aachen, Germany Purpose/Objective: Preoperative single fraction stereotactic radiosurgery (SRS) for brain metastases appears to be a promising approach with high efficacy and feasibility, and low toxicity reported in retrospective [1] and prospective [2] studies. A planned interim analysis of patients randomised into the international clinical phase III trial (PREOP-2, NCT05124236) was undertaken to evaluate the toxicity and feasibility of preoperative SRS compared with conventional postoperative fractionated stereotactic radiotherapy (FSRT). Keywords: neurocognition, SRS, tablet-based assessment 345

Material/Methods: On 9 th October 2024, serious adverse event (SAE) reports and dates of preoperative SRS and postoperative FSRT