Proton arc therapy
Rotating the proton beam continuously around the patient instead of firing from a few fixed angles, to spread the entrance dose and sharpen the target dose.
Proton arc delivers many low-weight spots from a continuously rotating gantry, improving conformality and robustness to range uncertainty. Vendors have released treatment-planning implementations and first patients have been reported at a small number of centres; a September 2026 search of ClinicalTrials.gov found no randomised comparison against intensity-modulated proton therapy. Delivery time and quality assurance are the practical barriers.
How it works
Spot-scanned protons are delivered during continuous gantry rotation, with energy layers distributed across angles so each direction contributes only part of the dose.
- Better normal-tissue sparing than fixed-field proton therapy in planning studies
- More robust to setup and range error
- Runs on existing proton hardware
- No comparative clinical outcome data
- Long delivery and QA times
- Adds planning complexity for uncertain benefit
Latest papers
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