Linac FRACtionated Radiosurgical THALamotomie in Tremors (FRACTHAL)


Radiosurgical thalamotomy on GammaKnife has been shown to be effective in the management of tremors. However, several teams describe a significant risk of severe neurological complications. In addition, fitting the invasive frame and the need to travel to GammKnife centers often limit access to treatment in this population of elderly patients. Linear accelerators have greatly improved their precision, now reaching that of GammaKnife. A possible alternative is therefore to treat patients on linear accelerators, without an invasive frame. The objective of the FRACTHAL study is to assess the feasibility and safety of treatment of essential and / or parkinsonian tremor by fractional radiosurgical thalamotomy on a linear accelerator. The main hypothesis of the FRACTHAL study is based on the fact that dividing the dose into 3 sessions will both protect healthy tissue around the target while maintaining therapeutic efficacy on the treatment target.

Full Title of Study: “Linac FRACtionated Radiosurgical THALamotomy in Tremors : a Phase II Study”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Treatment
    • Masking: None (Open Label)
  • Study Primary Completion Date: March 2026


  • Radiation: Radiosurgical thalamotomy on GammaKnife
    • fractional radiosurgical thalamotomy on an accelerator (3 sessions of 50 Gy at the isocenter )

Arms, Groups and Cohorts

  • Experimental: Radiosurgical thalamotomy on GammaKnife

Clinical Trial Outcome Measures

Primary Measures

  • Treatment toxicity
    • Time Frame: 12 months
    • The treatment will be considered toxic in the event of the appearance, within 12 months after treatment, of non-regressive toxicity of grade> 1 according to the NCI-CTCAE V5.0 scale (symptomatic neurological deficit interfering with daily activities), and that this deficit is related to the treatment.

Secondary Measures

  • Treatment accuracy
    • Time Frame: At 6 and 12 months
    • Measurement of the shift between the position of the treatment isocenter and the position of the hypersignal center visible on the injected MRI
  • Tremor improvement
    • Time Frame: At 3, 6 and 12 months
    • It will be measured by decrease in FTM scale score for contralateral upper limb

Participating in This Clinical Trial

Inclusion Criteria

  • patient with disabling essential tremor, dystonic and / or parkinsonian in one or more limbs superiors ; – patient contraindicated or refusing deep brain stimulation ; – patient ≥ 18 years old, – women of childbearing potential must take effective contraception ; – signature of informed consent ; p- atients who benefited from contralateral thalami c stimulation can be included in the study Exclusion Criteria:

  • brain irradiation history ; – contraindication or inability to perform injected MRI ; – life expectancy <12 months ; – claustrophobic patient who cannot stand the radiotherapy mask ; – abnormal anatomy of the thalamic region ; – treatment with a trial drug within 30 days of entering the study ; – presence of medical, psychological, social or geographic factors likely to modify the patient's compliance with the protocol under study or the monitoring or signing of the consent

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 99 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Centre Hospitalier Universitaire de Nice
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Contact(s)
    • Cécile ORTHOLAN, 00 377 97 98 84 20,

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