Proton Radiosurgery: Current Concepts and Limitations for CNS Radiosurgery

Area of Science:

• Neurology
• Radiation Oncology
• Medical Physics

Background:

• Stereotactic radiosurgery (SRS) is a standard treatment for CNS disorders.
• Proton therapy offers physical and dosimetric advantages over photon therapy.
• Proton SRS (PSRS) adoption is limited by facility availability, cost, and research gaps.

Purpose of the Study:

• To review the current clinical outcomes of proton SRS (PSRS) for various intracranial pathologies.
• To compare the efficacy and safety of PSRS with traditional photon-based SRS.
• To identify areas for future research to support wider adoption of PSRS.

Main Methods:

• Literature review of published clinical outcomes for PSRS across different CNS conditions.
• Analysis of data on obliteration rates, tumor control, toxicity, and eye retention.
• Synthesis of findings for conditions including AVMs, meningiomas, vestibular schwannomas, pituitary tumors, brain metastases, and uveal melanoma.

Main Results:

• PSRS demonstrates favorable obliteration rates for AVMs, particularly in deep or eloquent locations.
• Effective tumor control and manageable toxicity are observed for vestibular schwannomas and pituitary tumors.
• PSRS achieves high local control rates for brain metastases and excellent tumor control with eye retention for uveal melanoma.

Conclusions:

• Proton SRS is effective and safe for diverse intracranial pathologies.
• Limited, often retrospective, data necessitates further investigation.
• Understanding limitations and conducting comparative studies are crucial for advancing proton SRS.