FLASH radiotherapy: Newsflash or flash in the pan?

Ionizing radiation with ultra-high dose rates (>40 Gy/s), known as FLASH, has drawn great attention since its introduction in 2014 1 .It has been shown to markedly reduce radiation toxicity to normal healthy tissues while inhibiting tumor growth with similar efficiency as compared to conventional dose rate irradiation in pre-clinical models.Some believe that FLASH irradiation holds great promises and is perhaps the biggest finding in recent radiotherapy history.However, others remain skeptical about the replication of FLASH efficacy in cancer patients with concerns about technical complexity, lack of understanding of its molecular radiobiological underpinnings, and reliability.This is the premise debated in this month's Point/Counterpoint.