Marianna Alunni-Fabbroni (Germany)

University Hospital, LMU Munich Department of Radiology

Author Of 1 Presentation

A MULTISCALE AND MULTI-TECHNIQUE APPROACH FOR THE CHARACTERIZATION OF THE EFFECTS OF SPATIALLY FRACTIONATED X-RAY FLASH IRRADIATION IN LUNGS AND BRAINS

Session Type
Spacial Fractionation
Date
Fri, 03.12.2021
Session Time
10:50 - 11:50
Room
Room 2.31
Lecture Time
11:40 - 11:50

Abstract

Background and Aims

Accurate methods for monitoring the efficacy of treatments are key in radiooncology, where the quest for imaging techniques providing in three-dimensions (3D) both high spatial and contrast resolutions is incessant. X-ray Phase Contrast-Computed Tomography (XPCI-CT) is here proposed as a label-free, full-organ, multi-scale and 3D approach to study irradiated tissues with high sensitivity.

The aim is to visualize and characterize the effects of FLASH irradiations using broad beam (BB) and spatially-fractionated microbeams (MRT) with ex-vivo XPCI-CT for virtual 3D histology.

Methods

We delivered X-ray BB and MRT on healthy lungs or on healthy and glioblastoma-bearing brains of Fisher rats; irradiations were performed at the ID17 station of the European Synchrotron Radiation Facility using a dose rate of ~14000 Gy/s. After sacrificing the animals, target organs were removed, fixed and imaged by XPCI-CT using voxel sizes down to 0.73 µm3. Afterwards samples were analysed by histology, X-ray wide-angle scattering and fluorescence.

Results

XPCI-CT allowed the depiction of brain and lungs anatomical details down to the cellular level, the identification of tumour tissue, necrosis, calcifications and micrometric MRT-transections within brains and of radiation induced fibrosis in lungs. BB irradiations produced the largest amount of fibrotic tissue while MRT caused isolated scars with small iron accumulations and calcium deposits in damaged blood vessels. A complementary structural/chemical characterization of the detected structures was also achieved.

Conclusions

The proposed approach provides a supportive technique for 3D imaging-based virtual histology and for an accurate description of post-treatment conditions of biological tissues supplementing the capabilities of standard lab-based techniques.

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