The Biophysics of Flash Radiotherapy: Tools for Measuring Tumor and Normal Tissues Microenvironment

Area of Science:

• Radiation Oncology
• Biophysics
• Medical Physics

Background:

• Ultra-high dose rate radiotherapy, known as Flash radiotherapy (FLASH-RT), presents a promising approach to enhance radiotherapy's therapeutic ratio.
• FLASH-RT aims to preserve normal tissue function while retaining potent tumor-killing capabilities.
• The precise biophysical mechanisms underlying the FLASH effect are still under investigation, with hypotheses including oxygen depletion, modified free-radical reactions, and distinct biological responses.

Purpose of the Study:

• To provide a comprehensive overview of experimental and computational tools for investigating the tumor and normal tissue microenvironment during FLASH-RT.
• To analyze various in vitro, ex vivo, and in vivo systems employed in FLASH response studies.
• To highlight computational and imaging technologies that could advance the understanding of FLASH-RT biophysics and facilitate clinical translation.

Main Methods:

• Review of experimental methodologies (in vitro, ex vivo, in vivo) used to study FLASH responses.
• Analysis of computational modeling and simulation techniques relevant to FLASH-RT.
• Description of advanced imaging technologies for microenvironmental assessment.

Main Results:

• Identification of diverse experimental systems for studying FLASH effects across different biological scales.
• Overview of computational tools for modeling dose deposition and biological interactions.
• Discussion of imaging modalities for probing tissue responses to FLASH-RT.

Conclusions:

• A range of experimental and computational tools are available to investigate the FLASH effect.
• Understanding the biophysical basis of FLASH-RT requires integrating data from multiple systems and techniques.
• Further development and application of these tools are crucial for the safe and effective clinical translation of FLASH-RT.