Imma Martínez-Rovira (Spain)
Universitat Autònoma de Barcelona (UAB)
Physics Department
Dr. I. Martínez-Rovira is a researcher at the Physics Departament of the Universitat Autònoma de Barcelona (UAB). Her research is devoted to the development of innovative radiotherapy approaches, such as spatially fractionated radiotherapy (SFRT), FLASH-RT and the combined use of RT and nanoparticles. Her studies involve experimental dosimetry, Monte Carlo simulations, as well as radiobiological studies.

Moderator of 1 Session

 Online Program
FLASH Mechanisms Track

FLASH Mechanisms: Physico-Chemistry after FLASH-Irradiation and Oxygen Contribution

Session Type
FLASH Mechanisms Track
Date
30.11.2022
Session Time
16:30 - 17:00
Room
Hall 113-114
Chair(s)

Presenter of 1 Presentation

 Online Program

INFRARED MICROSPECTROSCOPY TO ELUCIDATE THE UNDERLYING BIOMOLECULAR MECHANISMS OF FLASH-RT

Session Type
FLASH Mechanisms Track
Session Name
0860 - FLASH Mechanisms: In Vivo (Part III) - (Oral presentations) (ID 70)
Date
02.12.2022
Session Time
10:40 - 11:40
Room
Hall 133-134
Presenter
Lecture Time
10:40 - 10:49

Abstract

Background and Aims

FLASH radiotherapy (FLASH-RT) is an emerging modality that uses high dose rates of radiation to enable curative doses to the tumour while preserving normal tissue. The impressive biological studies showed the potential of FLASH-RT to revolutionize radiotherapy cancer treatments. However, the complex biological basis of FLASH-RT is not fully known yet.

Within this context, our aim is to get deeper insights into the biomolecular mechanisms underlying FLASH-RT through Fourier Transform Infrared Microspectroscopy (FTRIM).

Methods

C57B6 female mice were whole brain irradiated at 10 Gy with eRT6-Oriatron (PMB-Alcen, France) as already described (Montay-Gruel, PNAS, 2019). FLASH-RT was delivered in 1 pulse of 1.8 μs and CNV at 0.1 Gy/s. Brain were sampled and prepared for analysis 24h post-RT.

FTIRM was performed at the MIRAS-BL of ALBA Synchrotron using the BRUKER 3000 Hyperion microscope coupled to a Vertex 70 spectrometer. Infrared raster scanning maps of the whole mice brain sections were collected for each sample condition with a beam spot size of 100x100 mm2. Principal Component Analysis (PCA) was performed in different ROIs of the brain sections.

Results

Preliminary PCA results evidenced a clear separation between conventional and FLASH-RT irradiations in the fingerprint region. An analysis of the loading pots revealed that most of the variance accounting for the separation between groups was associated to distinct conformational changes in the Amide I band. Also, DNA rearrangements varied as a function of the irradiation configuration. Cluster separation was also present in the lipid region, being correlated with changes in the CHx vibrational bands. Relevant biomarkers for lipid modifications (relative content of lipids, lipid chain alterations, lipid peroxidation, unsaturation) indicated distinct structural and biochemical perturbations in FLASH-RT with respect to conventional irradiations. Vibrational features were ROI-dependent.

Conclusions

This work provided new insights into the biomolecular effects involved in FLASH-RT through FTIRM.

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