Single high-energy arc proton therapy with Bragg peak boost (SHARP).

Area of Science:

• Radiation Oncology
• Medical Physics
• Oncology

Background:

• Base of skull tumors necessitate steep dose gradients for effective treatment due to proximity of critical organs.
• Proton beam therapy (PBT) is advantageous but often requires compromises to spare organs at risk (OARs).
• Existing PBT techniques aim to improve beam penumbra for better dose conformity.

Purpose of the Study:

• To introduce and evaluate a novel, collimator-free PBT planning technique called SHARP.
• To assess SHARP's ability to improve target coverage and OAR sparing for base of skull tumors.
• To compare SHARP against conventional PBT techniques.

Main Methods:

• Retrospective planning of three base of skull chordoma cases using three PBT techniques: conventional intensity-modulated PBT (IMPT), high-energy proton arc therapy (HE-PAT), and the novel SHARP technique.
• Utilized the Monaco 6 treatment planning system for all treatment plans.
• SHARP combines HE-PAT with conventional Bragg peak spot placement.

Main Results:

• The SHARP technique demonstrated improved PBT penumbra in the plane perpendicular to HE-PAT beams.
• Penumbra differences were minimal in the plane parallel to HE-PAT beams.
• SHARP effectively reduced the dose-averaged linear energy transfer (LET) to surrounding organs at risk.

Conclusions:

• A novel PBT planning technique, SHARP, was successfully developed and implemented.
• Initial findings suggest SHARP has the potential to enhance PBT treatment precision for base of skull tumors.
• SHARP may offer improved OAR sparing and target coverage compared to conventional PBT methods.