Portal Imaging System for Cancer Patients Undergoing Particle Beam Therapy

Provides the Charged Particle Beam’s View of a Patient’s Anatomy to Improve Radiation Delivery

This radiographic monitoring system tracks particle beam delivery within a patient undergoing particle therapy. The goal of radiation therapy is to maximize the treatment dosage delivered to a tumor while minimizing exposure of surrounding healthy tissue. Studies have shown that charged particle therapies such as proton therapy and heavy ion therapy significantly reduce toxicity to normal tissue while focusing radiation on a tumor. However, real-time guidance in charged particle therapy is limited by the finite range of the charged particles, which makes it difficult to determine the precise position of the tumor target within the beam aperture.

Higher energy particles during the interaction with matter can produce secondary particles such as neutrons, electrons, x-rays and gammas. Neutrons and photons, which tend to be more penetrating than the charged particles, typically give the largest contribution to the secondary dose in out-of-field organs. Researchers at the University of Florida have developed a portal imaging system for charged particle therapy based on real-time image acquisition and in situ dose monitoring. It uses the exit neutrons and photons generated within the patient during treatment to pinpoint where the beam source targets and measure the dosage applied to the region.

Application

Portal imaging system to produce radiographic images that improve particle therapy dosing at targeted regions

Advantages

• Generates radiographic images of patient anatomy, enabling users to assess dosage to anatomical structures adjacent to the target region
• Synchronizes with a video scan or camera scan, providing continuous 2D or 3D images of the patient
• Measures spatio-spectral distribution of secondary neutrons, providing additional dose information to determine risk of prompting secondary neutron-induced cancer

Technology

First-of-its-kind proton portal imaging system that provides “beam’s eye view” or portal of patient anatomy. This particle therapy portal imaging system provides radiographic images of a patient anatomy. When a charged particle beam consisting of high-energy ions lands on a target, it generates a secondary exit neutron and photon flux. The imaging system uses these neutron and photon emissions within the irradiated body to generate radiographic images of the patient. These images inform accurate assessment of dosage delivery to a tumor target and surrounding anatomical structures.