S954
Clinical - Non-malignant & functional radiotherapy
ESTRO 2026
Policlinico A.Gemelli, roma, Italy. 3 UOS Fisica Medica, Ospedale Isola Tiberina-Gemelli Isola, roma, Italy. 4 UOC Diagnostica per Immagini, Ospedale Isola Tiberina-Gemelli Isola, Roma, Italy. 5 UOC Diagnostica per Immagini, Fondazione Policlinico A.Gemelli, Roma, Italy. 6 UOC Neurochirurgia, Fondazione Policlinico A.Gemelli, roma, Italy. 7 Centro di Eccellenza Oncologia radioterapica medica diagnostica per Immagini, Ospedale Isola Tiberina-Gemelli Isola, Roma, Italy Purpose/Objective: Acoustic neurinoma is a benign tumor affecting the eighth cranial nerve, representing 6-10% of all intracranial tumors. Stereotactic radiosurgery ( SRS ), either single-fraction and fractionated SRS, is a consolidated alternative treatment to surgery. This study aims to analyze our preliminary experience with the robotic SRS CyberKnife® ( CK ) in a cohort of 50 consecutive treated at Gemelli Isola with the aim to evaluate compliance, feasibility, and tolerability of our SRS protocols. Material/Methods: Fifty consecutive patients with volume-enhanced acoustic neurinomas treated with CyberKnife® at Gemelli Isola Brain Suite over one year were included. Data on diagnosis, demographics, symptoms, and treatment (single 12 Gy SRS or 3 × 6 Gy fractions) were extracted from a prospective database. Patients were followed clinically at 1 and 3 months, then every 6 months or as needed Results: Median follow-up was 10 months ( 5-15 )Based on the neurinoma Koos staging and auditory function ( anacusia vs hipoacusia ) we delivered single fraction radiosurgery or 3 fractions SRS.The median volumes of GTV were 0.48 [0.16-1.20]cc and 1.93[0.48-5.82]cc respectively for patients who received single-fraction and 3-fraction-SRS. Treatment plans were prescribed at 80.90[77.70-85.20]% of maximum dose and last 37[26-45] min, prescription dose covered 99.2[98- 100]% of GTV with a CI 1.39[1.10-2.08].Circular collimation was used with 91[64-121] nodes and 140[76-233] beams.In these consecutives patients treated with CyberKnife® radiosurgery, variable volumetric responses were observed. Following single- fraction treatment at 12 Gy, tumors showed an initial mean volume increase of 45.1% (median 29.0%), followed by progressive reductions, indicating transient swelling and gradual shrinkage. In patients treated with 3 fractions SRS, 67% of tumors showed volume expansion at 3 months (33% showed reduction), while at 9 months the proportion of tumors decreasing in size increased to 53%, with 47% still showing expansion, suggesting a gradual shift from early swelling to later stabilization or shrinkage.The treatment was well tolerated, 23 patients reporting transitory side effects.The most common were
radiosurgery (SRS) might be a non-invasive method to treat this condition by blocking the electric conduction of the spasms. This prospective observational protocol (NCT06309810) aimsto evaluate the clinical activity and tolerability of SRS in patients affected by refractory spasticity, hypertonia, or spasms. Material/Methods: Patients with diffuse refractory spasticity, highly impairing spasticity, hypertonia, or spasms unresponsive to systemic therapies were treated with linac-based SRS to the spinal nerves. The treatment dose was 50 Gy/1 fx. The target was represneted by the identified spinal nerve with a PTV lateral margin of 2 mm. Patients were simulated and treated with general anesthesia or sedation to avoid spasms during treatment. Primary end-point was the reduction of the muscular resistance to passive movement measured with the Modified Ashworth Scale (MAS). Secondary end-points were toxicity, quality of life and nursing work. Results: Seven patients were treated with SRS. The median follow-up was 10 months (range 6-18 months). Target spinal nerves were identified with electromyography. Patients were treated to multiple lumbar-sacral nerves bilaterally or monolaterally in one case. Six out of 7 patients reported a MAS improvement and a spasticity reduction (4 cases) or complete resolution (2 cases). One patient with continous and persistent spasms and a minimal residual sensitivity to the left lower limb had no effect from the treatment and developed neuropatic pain treated with neuroleptics and phenol perinerval injection. No other side effects occurred at the last follow-up. Conclusion: This is the first clinical trial evaluating the use of a linac-based SRS for the treatment of spasticity. These preliminary results documented a clinical activity of SRS with no safety concerns. A longer follow-up is necessary to assess betterthe effectiveness, toxicity, and response duration. Keywords: SRS, spasticity, hypertonia Digital Poster 4647 Acoustic Neurinomas Treated with CyberKnife® SRS: Early Experience on Tolerability and Feasibility Mariavittoria Leone 1 , Federica Pavoncello 1 , Isabella Costamagna 2 , Antonella Bufacchi 3 , Leonardo Vattermoli 4 , Cesare Colosimo 5 , Tiziana Malatesta 3 , Silvia Chiesa 2 , Giuseppe Maria Della Pepa 6 , Alessandro Olivi 6 , Vincenzo Valentini 7 , Maria Antonietta Gambacorta 2 , Giuseppe Minniti 1 , Francesco Miccichè 1 1 UOC Radioterapia, Ospedale Isola Tiberina-Gemelli Isola, roma, Italy. 2 UOC Radioterapia, Fondazione
Made with FlippingBook - Share PDF online