Related Experiment Video
Updated: May 6, 2026
Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy
Published on: June 7, 2015
Monoenergetic Bragg peak FLASH proton therapy with universal range shifter in multi-field optimization
Qi Zhang1, Yiling Zeng2, Bo Pang3
1Department of Medical Physics, School of Physics and Technology, Wuhan University, Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan 430072, China, Wuhan, Hubei, 430072, CHINA.
A new method for proton therapy uses a universal range shifter (URS) for conformal FLASH radiotherapy (FLASH-RT). This approach achieves the FLASH effect with better normal tissue dose protection compared to transmission beam techniques.
Area of Science:
- Medical Physics
- Radiation Oncology
- Biophysics
Background:
- Proton therapy, particularly monoenergetic high-energy Bragg peak (monoBP) proton therapy, shows promise for conformal FLASH radiotherapy (FLASH-RT).
- Current methods require beam-specific proton modulation devices for dose conformity, and beam switching can disrupt ultra-high dose rate (UHDR) delivery, compromising the FLASH effect.
- A novel approach is needed to achieve conformal FLASH-RT using simpler modulation techniques.
Purpose of the Study:
- To propose and evaluate a novel methodology for monoenergetic high-energy Bragg peak (monoBP) conformal FLASH-RT using only a universal range shifter (URS).
- To compare the efficacy and safety of URS-modulated monoBP FLASH-RT with transmission beam (TB) FLASH-RT.
Main Methods:
- Developed an optimization algorithm to simultaneously optimize URS thickness and dose distribution based on multi-field optimization.
- Investigated two 218 MeV proton beam FLASH techniques: URS-modulated monoBP FLASH and transmission beam (TB) FLASH.
- Evaluated plans for 10 brain and 10 lung cancer cases under identical robust optimization constraints, analyzing delivery parameters, dose coverage, and dose rate metrics.
Main Results:
- Both URS-modulated monoBP FLASH and TB FLASH achieved comparable target dose coverage (D98% > 97.8%) meeting clinical requirements.
- monoBP FLASH plans significantly reduced the mean dose to normal tissues in both brain (6.6 Gy vs 9.7 Gy) and lung (3.3 Gy vs 4.2 Gy) cases compared to TB FLASH.
- Both modalities achieved 100% V40Gy/s for dose-averaged dose rate; however, TB FLASH showed higher V40Gy/s for averaged dose rate (61.5% brain, 61.3% lung) compared to monoBP FLASH (37.4% brain, 26.9% lung).
Conclusions:
- A novel monoenergetic high-energy Bragg peak (monoBP) conformal FLASH-RT methodology utilizing a fixed universal range shifter (URS) has been successfully proposed.
- The proposed monoBP FLASH-RT approach meets the requirements for the FLASH effect.
- This URS-based monoBP FLASH-RT demonstrates superior normal tissue dose protection compared to transmission beam (TB) FLASH-RT.
More Related Videos
08:34Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
07:57Positron Emission Tomography-based Dose Painting Radiation Therapy in a Glioblastoma Rat Model using the Small Animal Radiation Research Platform
Published on: March 24, 2022
