An Effectiveness and Toxicity of CyberKnife Based Radiosurgery for Parkinson Disease

Basic treatment patients with Parkinson's disease (PD - Parkinson's disease) or essential tremor (ET - essential tremor) is a pharmacotherapy. In the case of lack of its effectiveness, the gold standard procedure is deep brain stimulation (DBS). Despite the proven efficacy, still remains a group of patients not eligible for this treatment. in such cases, ablation within the deep structures of the brain (thalamotomy, subthalamotomy, pallidotomy) can be considered. Thermoablation and radiosurgery (SRS - Stereotactic radiosurgery) are used: SRS is prefered for patients who are not candidates for invasive procedures. 27 patients will be enrolled in this study. All patients will be immobilized in thermoplastic masks and planned (RT) on the base of CT/MRI fusion. The initial total dose in the target volume (thalamic nuclei complex - VoP and VoA ) will be 70 Gy given in one fraction. The dose will be escalated every 5 Gy and the treatment effect and possible side effects will be evaluated. Dose escalation will be finished at a dose at which the effect of treatment will be satisfactory, or if side effects are unacceptable. The highest dose tested dose will be 110 Gy. Three patients will be irradiated with particular doses and observed at least 3 moths; then study will be continued. Patients will be controlled 3, 6, 9, 12, 18 months after treatment completion and, next every each 6 months. Neurologic and neuropsychologic status, local effect (MRI ) and eventual toxicity will be checked during follow-up (FU).