2355 - Functional Outcome Evaluation of Stereotactic Radiosurgery Treatment for Essential and Parkinsonian Tremor - A Private Institution Evaluation

Materials/Methods: 105 patients underwent radiosurgery for treatment of their tremor. 93 of which had Benign Essential Tremor and 12 with Parkinsonian Tremor. We treated using radiosurgery to the contralateral Vim thalamic nucleus at a dose ranging from 65 Gy to 130 Gy using a 4mm single isocenter. We conducted a retrospective, single institution review of 90 patient records compliant with routine follow up at a median of 6 months treated between 2005 and 2023 at our facility (Tacoma/Valley Radiation Oncology Centers, Tacoma, WA).

Results: 46 female and 59 male patients were treated with radiosurgery for tremor after conservative measures failed. A total of 82% of patients experienced clinically meaningful improvement. Essential and Parkinsonian Tremor experienced 82% and 67% improvement respectively. Long-term symptomatic side effects were seen in 8% of patients at a median of 9 months post treatment. In patients with side effects, all experienced weakness in their extremities. Additionally, 6% experienced unsteady gait, scalp numbness (1%) and visual (1%) or verbal difficulties (1%). Side effects predominately occurred in males (90%). Patient side effects were addressed utilizing steroids, hyperbaric oxygen therapy and Physical Therapy. This resulted in 90% of patients experiencing improvement of side effects over time. Pre-treatment duration of tremor was evaluated in regards to efficacy of treatment. Results showed that patients with tremor duration of <5 years had 73% improvement, 5-15 year duration 88%, 15-30 year duration 87%, 30+ year duration 91% experienced improvement.

Conclusion: Radiosurgery proved to be effective for tremors. Side effect profile was minimal and largely resolved with treatment and time. Radiosurgery should be considered in patients resistant to conservative therapies.