Implementing ocular treatment with pencil beam scanning: the FHCC experience

Area of Science:

• Radiation Oncology
• Medical Physics
• Ophthalmology

Background:

• Fred Hutchinson Cancer Center developed an in-house method for ocular proton therapy.
• This method utilizes a modified pencil beam scanning (PBS) beamline and a commercial treatment planning system.
• The study details the workflow and initial patient experiences.

Purpose of the Study:

• To outline the novel in-house workflow for ocular proton therapy at FHCC.
• To present experiences from the first 40 patients treated with this method.
• To demonstrate the feasibility of using a general-purpose PBS beamline for ocular proton therapy.

Main Methods:

• Developed in-house treatment chair and gaze localization systems.
• Utilized CT imaging for treatment planning and a Monte Carlo algorithm for dose calculation.
• Collected data on patient characteristics, dose-volume statistics, treatment time, and travel distances.

Main Results:

• Average patient age was 63.9 years; tumor sizes varied.
• Dose to Gross Tumor Volume (GTV) met planning goals in 16 of 40 patients.
• Median doses to organs at risk (OARs) were within acceptable ranges; treatment duration averaged 25 minutes per fraction.

Conclusions:

• Ocular proton therapy can be effectively delivered using a general-purpose PBS beamline.
• This approach provides a viable solution for institutions without dedicated ocular beamlines.
• The FHCC method demonstrates successful adaptation of existing technology for specialized treatment.