ESTRO 2024 - Abstract Book

S5241

Radiobiology - Normal tissue radiobiology

ESTRO 2024

Conclusion:

Both normal-ODRT (60Gy/30F/qd) and normal-TDRT (45Gy/30F/bid) were safe for mice. Although no significantly differences in functional change of the BSCB was observed between arms, we demonstrated structural BSCB changes using TEM. Hypofractionated radiotherapy (60Gy,3F/qd as well as 45Gy/3F/bid) was fatal with the former causing more severe BSCB damage. These data can aid the future development of studies aimed at safely increasing the blood-brain barrier penetration with radiotherapy to improve penetration of systemic therapies, such as immunotherapy.

Keywords: radiotherapy, blood-spinal cord barrier, TEM

References:

1.Zeng H, Xie P, Meng X, et al: Risk factors for brain metastases after prophylactic cranial irradiation in small cell lung cancer. Sci Rep 7:42743, 2017

2.Zeng H, Li R, Hu C, et al: Association of Twice-Daily Radiotherapy With Subsequent Brain Metastases in Adults With Small Cell Lung Cancer. JAMA Netw Open 2:e190103, 2019

632

Proffered Paper

The FLASH Effect is dependent on Dose per Pulse and not Mean Dose Rate for Abdominal Irradiations