ESTRO 2025 - Abstract Book

S676

Clinical - CNS

ESTRO 2025

1512

Digital Poster Novel frameless thalamotomy on CyberKnife S7 treatment delivery system in general anesthesia Ivana Alerić 1,2 , Ana Mišir Krpan 1 , Maja Karaman Ilić 3,2,4 , Mihaela Mlinarić 1 , Vanda Leipold 1,2 , Domagoj Kosmina 1 , Hrvoje Vavro 1 , Nataša Gojak 3 , Marica Keser 1 , Alen Kosmat 1 , Josip Paladino 3 , Dragan Schwarz 3 1 Radiotherapy Department, Specialty Hospital Radiochirurgia Zagreb, Sveta Nedelja, Croatia. 2 Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia. 3 Department of Surgery, Specialty Hospital Radiochirurgia Zagreb, Sveta Nedelja, Croatia. 4 Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia Purpose/Objective: Parkinson disease (PD) patients dealing with dominant tremor can be treated on CyberKnife robotic radiotherapy devices. While awake or general anesthesia treatments on the Gamma Knife are already a well-established practice, frameless stereotactic radiosurgery (SRS) provides a major advantage in patient comfort avoiding invasive frame fixation in favor of thermoplastic immobilization masks. Due to excessive tremor, one of the patients scheduled for thalamotomy (male, 87y.o.) was not able to undergo the procedure. Material/Methods: In collaboration with the anesthesiology team, neurosurgeon, radiation oncologist, medical physicists and radiotherapists, the patient was induced into general anesthesia, which reduced tremor symptoms, and simulated for SRS treatment. The laryngeal mask airway was used to secure the patient's airway during anesthesia. After treatment planning and approval, the plan was executed in the demonstration mode to verify that all nodes are feasible, ensuring that the robotic arm does not collide with the patient mask, tubes, ventilator, or other medical equipment in the room. Patient specific quality assurance of the treatment plan was performed on SRS MapCHECK® to ensure consistency in the delivered dose. Results: In October 2024, four days after the simulation, the patient was again induced into general anesthesia. Dose of 130 Gy was delivered in the ventralis intermediate nucleus (VIM) of the left thalamus. A fixed 5 mm collimator was used to deliver dose to the target volume. Detection and correction of the potential shifts were tracked in real-time with 6D Skull Tracking. The treatment lasted 47 minutes, with a 20 seconds tracking range. Three hours after the treatment, the patient was released from the hospital. First results are expected after 3 months, but in November 2024 patients reported subjective improvement in tremor symptoms. No toxicity has been reported.