Navigating the straits: realizing the potential of proton FLASH through physics advances and further pre-clinical characterization

Autor: John D. Fenwick, Christopher Mayhew, Simon Jolly, Richard A. Amos, Maria A. Hawkins
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Frontiers in Oncology, Vol 14 (2024)
Druh dokumentu: article
ISSN: 2234-943X
DOI: 10.3389/fonc.2024.1420337
Popis: Ultra-high dose-rate ‘FLASH’ radiotherapy may be a pivotal step forward for cancer treatment, widening the therapeutic window between radiation tumour killing and damage to neighbouring normal tissues. The extent of normal tissue sparing reported in pre-clinical FLASH studies typically corresponds to an increase in isotoxic dose-levels of 5–20%, though gains are larger at higher doses. Conditions currently thought necessary for FLASH normal tissue sparing are a dose-rate ≥40 Gy s-1, dose-per-fraction ≥5–10 Gy and irradiation duration ≤0.2–0.5 s. Cyclotron proton accelerators are the first clinical systems to be adapted to irradiate deep-seated tumours at FLASH dose-rates, but even using these machines it is challenging to meet the FLASH conditions. In this review we describe the challenges for delivering FLASH proton beam therapy, the compromises that ensue if these challenges are not addressed, and resulting dosimetric losses. Some of these losses are on the same scale as the gains from FLASH found pre-clinically. We therefore conclude that for FLASH to succeed clinically the challenges must be systematically overcome rather than accommodated, and we survey physical and pre-clinical routes for achieving this.
Databáze: Directory of Open Access Journals