Bragg Peak and Organ Protection in Particle Therapy
One of the main reasons particle therapy is reviewed in selected cancer cases is its dose distribution.
Unlike conventional X-ray radiation, proton and carbon-ion beams can release much of their radiation dose at a defined depth inside the body. This physical characteristic is known as the Bragg Peak.
After reaching the target depth, the dose can fall sharply, which may reduce unnecessary radiation exposure beyond the tumor.
This is clinically important when a tumor is located close to organs or structures that are sensitive to radiation.
These nearby structures are often called organs at risk, or OARs.
Examples include the brain, spinal cord, optic nerves, eyes, salivary glands, lungs, heart, liver, stomach, bowel, bladder, rectum, kidneys, and major blood vessels.
The goal is not simply to use a more advanced technology.
The practical purpose is to deliver an effective dose to the tumor while reducing avoidable dose to surrounding normal tissues.
This may be relevant in selected cases involving:
- Tumors located near critical organs
- Re-irradiation after previous radiation therapy
- Pediatric or young adult patients
- Recurrent tumors in previously treated areas
- Cases where conventional radiation may be limited by normal tissue tolerance
However, the Bragg Peak does not automatically make particle therapy suitable for every patient.
Hospitals must still review the cancer type, disease stage, tumor size and location, prior treatment history, prior radiation records, imaging findings, and the patient’s overall condition.
Recent imaging files, such as CT, MRI, or PET-CT in DICOM format, are often essential to assess whether particle therapy planning is technically and clinically feasible.
APIS helps coordinate communication and document submission to Korean hospitals for selected international cases.
* Final treatment decisions are determined solely by the treating hospitals and physicians.
