ESTRO 2025 - Abstract Book

S736

Clinical - CNS

ESTRO 2025

3873

Digital Poster Refractory SPAsticity and hypertonia or spasms treated with steReoTActic radiosurgery (SPARTA) Luca Nicosia 1 , Federico Ferrari 2 , Elena Rossato 2 , Andrea Gaetano Allegra 1 , Chiara De-Colle 1 , Niccolò Giaj-Levra 1 , Francesco Ricchetti 1 , Michele Rigo 1 , Edoardo Pastorello 1 , Fabio Marchioretto 3 , Massimo Zamperini 4 , Ruggero Ruggieri 1 , Filippo Alongi 1,5 1 Department of Advanced Radiation Oncology, IRCCS Sacro Cuore Don calabria, Negrar di Valpolicella, Italy. 2 Department of Rehabilitation, IRCCS Sacro Cuore Don calabria, Negrar di Valpolicella, Italy. 3 Neurological Unit, IRCCS Sacro Cuore Don calabria, Negrar di Valpolicella, Italy. 4 Department of Anesthesia, IRCCS Sacro Cuore Don calabria, Negrar di Valpolicella, Italy. 5 University of Brescia, University of Brescia, Brescia, Italy Purpose/Objective: Spasticity is a velocity-dependent increase in muscle stretch reflexes, associated with increased muscle tone as a component of upper motor neuron syndrome. It may occur in up to 80% of people affected by spinal cord injury, with the highest incidence in those with incomplete tetraplegia. Spasticity may affect patients’ quality of life by interfering with patients’ ability during wheelchair transfers, postures, or sleeping. Common treatments are represented by oral or i.v. medication (baclofen, diazepam, tizanidine) or surgical intervention (neurotomies, rhizotomies). However, patients can became progressively resistant to drugs and surgery requires experienced teams and is not without complications. In this context, stereotactic 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) aims to 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. 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: Four patients were treated with SRS. Target spinal nerves were identified with electromyography. One patient was treated to bilateral L4-S1 nerves and reported lower limb flaccidity 1 day after SRS that persisted 1 year after treatment (MAS 0 versus 3). One patient was treated to bilateral L4-S1 nerves and an immediate muscle flaccidity with a reduction of the abdominal discomfort (MAS 1 versus 3) that continued at 3 months of follow-up. One patient was treated to the bilateral L2-L3 nerves had a progressive spasm reduction starting few days after SRS that persisted 9 months after treatment (MAS 0 versus 2). The fourth patient was treated at the bilateral L4-L5 nerves and had a MAS reduction of 1 point (versus 2) within 6 months after SRS and at the last follow-up had a slight increase in spasm frequency. No acute treatment-related toxicities were reported. Conclusion: This is the first clinical trial on 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 better the effectiveness, toxicity, and response duration.

Keywords: Spasticity, SRS, spasms