MRgFUS Tremor Treatment - Insights for Patient Fingerprinting and Improved Treatment Protocol Derived from Advanced Machine Learning Analyses

Background: MRgFUS is a novel non-invasive and low-risk procedure for tremor treatment in essential tremor (ET) and Parkinson’s disease (PD) patients, improving patients’ lives dramatically. Treatments’ results and tremor improvement achieved are not always preserved in the long term. Since this is a relatively new treatment with evolving technology involving different mechanisms; technical, clinical and physiological, the reasons for this variability are not well known. The aim of this study is to retrospectively decipher these mechanisms and delineate the key factors with the most significant impact on sustained improved tremor outcome.

Methods: Unique Machine-Learning based data-analysis methods were applied on the most up-to-date patients database from our institution, in order to reveal critical factors related to treatment`s success. Patients` cohort included 64 patients - 36 diagnosed with ET and 28 with PD, all treated in our institution with MRgFUS between 11/2013 and 04/2018.

Results:
1. A robust tremor-evaluation metric was developed, providing physicians and researchers with a time-adaptive tool for predicting long-term treatment effect.

2. Most significant parameters collected in screening and in real-time during the treatment were detected and evaluated in importance and impact scores for treatment`s efficiency for both PD and ET patients. The parameters were divided into categories such as treatment related (e.g. energy-transfer) and radiological fingerprinting (e.g. lesion size).

3. Major differences were found between ET and PD patients concerning parameters` impact on long-term treatment success.

4. Correlations between SDR and available skull volume to the maximal sonication energy were shown to be statistically significant.

Conclusions: The results may have direct therapeutic implications on how patients are screened before treatment, and on MRgFUS treatment protocols for ET or PD patients.