Exploring stereotactic radiosurgery for tremor using the Varian cone planning system

Background: Stereotactic radiosurgery (SRS) is an effective treatment for essential tremor (ET) and Parkinsonian tremor (PT). However, current treatment methods can be time-consuming and expose patients to unnecessary radiation. This study investigates the use of the Varian TrueBeam system with FFF beam modes as a potential solution for these issues.

Methods: We recreated and evaluated treatment plans using the Varian TrueBeam and Eclipse Cone Planning system for ten patients previously treated for tremor cessation using a Novalis Tx linear accelerator with Brainlab planning system prescribed a maximum dose of 160 Gy. Analyses included beam-on delivery time, total MU, dose to brain and brainstem tissues, and confirmation of SRS cone accuracy.

Results: The TrueBeam cone delivery system is highly accurate. Our results demonstrated a significant reduction in monitor units (MU) and treatment delivery time shortened to 17-26 min beam-on time for all-Varian plans compared to 39 min for non-Varian (iPlan) plans (p < 0.0001). Furthermore, the Varian plans showed improved or similar dose fall-off and radiation dose to brainstem normal tissue.

Conclusion: Our findings suggest that the Varian TrueBeam system offers a safe and effective option for SRS tremor treatment, providing similar or superior treatment parameters compared to other LINAC-based SRS treatments. The reduced treatment times and improved patient comfort offered by this system make it a promising solution for future tremor treatments.