Improved clinical efficiency in CNS stereotactic radiosurgery using a flattening filter free linear accelerator

Area of Science:

• Medical Physics
• Radiation Oncology
• Neurosurgery

Background:

• Central nervous system (CNS) stereotactic radiosurgery (SRS) using linear accelerators (linacs) is time-intensive.
• Improving clinical efficiency is crucial for optimizing patient throughput and resource allocation.

Purpose of the Study:

• To evaluate the efficiency of a flattening filter free (FFF) linac for CNS SRS.
• To determine if FFF linac technology reduces treatment time and enhances clinical workflow compared to conventional linacs.

Main Methods:

• Retrospective review of 27 CNS SRS cases treated with a newly commissioned FFF linac.
• Analysis of beam on time (BOT), time in room (TIR), and clinical dose rate (CDR) as efficiency metrics.
• Regression analysis to identify factors influencing treatment time.

Main Results:

• FFF linac use more than tripled the clinical dose rate (mean 1820 MU/min).
• Mean BOT was 1:21 and mean TIR was 10:42.
• Factors like alignment images, treatment arcs, and intra-fraction imaging significantly impacted TIR.

Conclusions:

• FFF linac-based CNS SRS significantly shortens treatment duration (BOT and TIR) compared to conventional dose rates.
• Reduced treatment times may improve target localization by minimizing intrafraction motion.
• High-output FFF linacs enable efficient CNS SRS within standard clinical time slots.