FLASH Effect Is Not Always Induced by Ultra-high Dose-rate Proton Irradiation Under Hypoxic Conditions.
Anticancer Res
; 44(7): 2973-2979, 2024 Jul.
Article
in En
| MEDLINE
| ID: mdl-38925851
ABSTRACT
BACKGROUND/AIM:
Pre-clinical studies have shown that irradiation with electrons at an ultra-high dose-rate (FLASH) spares normal tissue while maintaining tumor control. However, most in vitro experiments with protons have been conducted using a non-clinical irradiation system in normoxia alone. This study evaluated the biological response of non-tumor and tumor cells at different oxygen concentrations irradiated with ultra-high dose-rate protons using a clinical system and compared it with the conventional dose rate (CONV). MATERIALS ANDMETHODS:
Non-tumor cells (V79) and tumor cells (U-251 and A549) were irradiated with 230 MeV protons at a dose rate of >50 Gy/s or 0.1 Gy/s under normoxic or hypoxic (<2%) conditions. The surviving fraction was analyzed using a clonogenic cell survival assay.RESULTS:
No significant difference in the survival of non-tumor or tumor cells irradiated with FLASH was observed under normoxia or hypoxia compared to the CONV.CONCLUSION:
Proton irradiation at a dose rate above 40 Gy/s, the FLASH dose rate, did not induce a sparing effect on either non-tumor or tumor cells under the conditions examined. Further studies are required on the influence of various factors on cell survival after FLASH irradiation.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Protons
/
Cell Survival
/
Proton Therapy
Limits:
Animals
/
Humans
Language:
En
Journal:
Anticancer Res
/
Anticancer res
/
Anticancer research
Year:
2024
Document type:
Article
Country of publication: