Advanced Therapy in Radiation Oncology and Molecular Imaging Characterisation (ATOMIC)

ATOMIC is a newly established research team at the Institut Curie, affiliated with the IRIS research unit led by Irène Buvat (Orsay campus; jointly affiliated with Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) and Université Paris-Saclay). The team builds upon the "Innovative Radiotherapy" research program developed between 2020 and 2023 and brings together radiation oncologists, medical physicists, and researchers from both the Curie Research Center and Hospital.
ATOMIC benefits from a state-of-the-art experimental radiotherapy platform equipped with preclinical irradiators (SAARP systems, ultra-high dose-rate FLASH electron irradiation, and proton irradiation), as well as access to next-generation clinical irradiation technologies, including proton FLASH, proton minibeam radiotherapy, and MRI-guided adaptive radiotherapy (MR-Linac).
FLASH radiotherapy was first discovered at the Institut Curie in 2014. The team has secured €34.9 million in funding through the France 2030 / ANR program to develop a prototype Very High-Energy Electron (VHEE) irradiation system. ATOMIC is also an active member of major international collaborations, including the Momentum consortium for MR-Linac research and the ESTRO Re-irradiation Working Group.

Research Mission

The project is embedded within a precision radiation oncology strategy driven by both imaging biomarkers (developed in collaboration with the ICE and RADIOME teams) and tissue biomarkers (developed with the IMPACT and ATOMIC teams). The overarching objective is to personalize radiation dose prescription and target volume definition in order to optimize the therapeutic ratio by maximizing tumor control while minimizing normal tissue toxicity.
The emergence of disruptive tissue-sparing technologies such as FLASH radiotherapy and proton minibeams requires a deeper understanding of their biological effects on both tumors and healthy tissues. ATOMIC therefore aims to characterize these effects using advanced imaging approaches and to identify predictive biomarkers of treatment response.

Strategic Research Axis 1 – Imaging-Based Prediction of Tumor and Normal Tissue Radiosensitivity

This research axis, conducted in close collaboration with the ICE team, aims to develop imaging biomarkers capable of predicting the radiosensitivity of both tumor and healthy tissues. Radiomic signatures extracted from pretreatment imaging, as well as delta-radiomic features derived from longitudinal imaging before and after treatment, are investigated to predict:
•    local tumor control, 
•    patterns of recurrence (in-field, out-of-field, local, or metastatic), 
•    radiation-induced toxicities affecting healthy tissues, such as cerebral radionecrosis. 
Ongoing projects focus on triple-negative breast cancer, esophageal cancer, prostate cancer, and head and neck cancers undergoing re-irradiation. In parallel, AI-driven pathomics, developed in collaboration with the IMPACT team, will provide complementary biomarkers for predicting tumor aggressiveness.

Strategic Research Axis 2 – Preserving Healthy Tissues and Their Function

This axis focuses on maximizing normal tissue preservation by integrating novel functional imaging approaches into radiotherapy planning.
Emerging imaging tracers, including FAPI PET, are used to improve the discrimination between metabolically active tumor tissue and post-radiation fibrosis or inflammation. These metabolic imaging data are combined with advanced beam optimization strategies to escalate the radiation dose within the tumor while sparing the most functionally important healthy tissues.
Multimodal image fusion—including SPECT/CT, 4D Cone-Beam CT (CBCT), and perfusion MRI—is co-registered with treatment planning CT scans. In collaboration with the RADIOME team, these datasets support biologically informed dose painting and functional treatment planning.

Strategic Research Axis 3 – Dosimetric Modeling of Combined External Beam Radiotherapy and Targeted Radionuclide Therapy

The third research axis aims to improve dosimetric modeling for the combination of External Beam Radiotherapy (EBRT) and Targeted Radionuclide Therapy (TRT) (Radiothérapie Interne Vectorisée, RIV), in collaboration with the ICE team.
The objective is to establish robust dosimetric equivalence models between systemic radionuclide irradiation and external beam irradiation, enabling accurate estimation of cumulative absorbed doses delivered to tumors and organs at risk.
This work represents a critical prerequisite for the clinical implementation of multimodal therapeutic strategies combining targeted radionuclide therapy with external beam radiotherapy, thereby expanding the therapeutic potential of precision radiation oncology