Absolute dosimetry for FLASH proton pencil beam scanning radiotherapy

Area of Science:

• Medical Physics
• Oncology
• Radiation Therapy

Background:

• A paradigm shift in clinical oncology is driven by ultra-high dose rate (UHDR) radiation, termed FLASH radiotherapy.
• FLASH radiotherapy shows potential for reduced side effects and improved cancer treatment efficacy compared to conventional dose rates.
• Accurate dosimetry for UHDR is a significant challenge for clinical implementation.

Purpose of the Study:

• To establish accurate dosimetry for FLASH proton beam radiotherapy.
• To develop a primary standard for measuring dose at UHDR.
• To ensure the safe and effective clinical application of FLASH radiotherapy.

Main Methods:

• Measurements using a primary-standard proton calorimeter.
• Derivation of necessary correction factors for absolute dose determination.
• Validation of dosimetry methods for UHDR proton beams.

Main Results:

• Achieved an absolute dose uncertainty of 0.9% (1 sigma) for FLASH proton beam radiotherapy.
• Established a primary standard for FLASH proton radiotherapy dosimetry.
• Demonstrated dosimetry accuracy comparable to conventional radiotherapy treatments.

Conclusions:

• The established primary standard enables accurate and consistent dose delivery for FLASH radiotherapy.
• This dosimetry advancement is crucial for the safe progression of clinical trials involving FLASH radiotherapy.
• Improved dosimetry will facilitate the broader clinical adoption of this innovative cancer treatment modality.