Biological Benefits of Ultra-high Dose Rate FLASH Radiotherapy: Sleeping Beauty Awoken

Area of Science:

• Radiation oncology
• Biophysics
• Preclinical research

Background:

• Conventional radiotherapy uses lower dose rates, potentially causing significant normal tissue damage.
• FLASH radiotherapy (FLASH-RT) utilizes ultra-high dose rates for radiation delivery.
• FLASH-RT has demonstrated a unique 'FLASH effect' with differential sparing of normal tissues.

Purpose of the Study:

• To summarize the current knowledge and historical research on the FLASH effect.
• To synthesize observations from various animal models and organs.
• To propose potential mechanisms and clinical applications of FLASH-RT.

Main Methods:

• Review of 40 years of published research on FLASH-RT.
• Synthesis of data from diverse experimental animal models (mice, zebrafish, pigs, cats).
• Analysis of findings across multiple organs including lung, gut, brain, and skin.

Main Results:

• FLASH-RT consistently shows relative protection of normal tissues compared to conventional dose rate radiotherapy.
• The FLASH effect has been observed across various species and organs.
• Decades of research have established the phenomenon, with ongoing investigation into its underlying mechanisms.

Conclusions:

• FLASH radiotherapy represents a significant advancement in radiation delivery technology.
• The observed normal tissue sparing effect of FLASH-RT holds promise for improved cancer treatment.
• Further research into mechanisms and clinical translation is warranted to optimize FLASH-RT applications.