Biomedical Physics in Radiation Oncology

IFIGENIA: New Linac for Nuclear Medicine and Molecular Imaging

Nuclear medicine and molecular imaging are widely used to diagnose and treat a wide range of diseases, including cancer, cardiovascular disease and brain disorders such as Alzheimer's and Parkinson's disease. However, the number of nuclear medicine procedures in Europe is significantly lower because most European countries lack the specialized equipment needed to produce the radioisotopes. Within the framework of the Horizon European Research Executive Agency (REA), funding has been received to develop a center of excellence (Excellence Hub) in South Eastern Europe (Greece, Slovenia, Bosnia and Herzegovina and Cyprus) to develop a novel accelerator dedicated to securing a production platform for a wide range of radioisotopes. A LINear ACcelerator (LINAC) provides a compact, cost-effective and environmentally friendly option that can be located in close proximity to hospitals. The tunability of LINACs allows energy levels, currents and targets to be adjusted, enabling the production of a wide range of radioisotopes. In particular, a similar facility, called NUSANO[5], is being built in West Valley City, Utah, USA, and will be operational in 2025. The novel center of excellence is called "IFIGENIA". 

FLASH Zebra: Investigation of Oxygen Depletion Hypothesis

The project focuses on achieving a scientific breakthrough in determining the role of oxygen at the FLASH effect. It is well known that irradiation with high dose rates (>40 Gy/s) causes a protective effect of healthy tissue while maintaining tumor control (FLASH effect). However, the mechanisms contributing to this effect are yet to be understood. Starting from the oxygen partial pressure (pO2), a critical parameter for the prevalence of the FLASH effect, this project aims to design in-vivo oxygen measurements during conventional and FLASH radiation treatment and thus to correlate oxygen distribution and depletion with biological endpoints in zebrafish embryos (ZFE).

PROMPT FLASH: Developing real-time dosimetry for in-vivo assessment during FLASH

FLASH radiotherapy demonstrates a striking biological sparing effect of normal tissues while keeping similar anti-tumor efficacy, termed the “FLASH effect”. The measurement of dose at ultra-high-dose-rates or FLASH rates is complex as dosimeters may be susceptible to saturation at ultra-high dose rates. An in-vivo method of verifying the delivered FLASH dose is currently not available. It is vital to guarantee the accuracy of the delivered dose during FLASH. The current proposal focuses on a new method for verifying delivered FLASH dose in-vivo using prompt gamma x-ray spectroscopic (PGXS) analysis of irradiated tissue, which uses Gadolinium-Based Contrast Agents (GBCA) to amplify gamma/X-ray emission. A graphite calorimetry methodology will be used as absolute dose reference.

gROS MC-FLASH: Developing novel Monte Carlo tool for FLASH

The application of ultra-high dose rates (>40 Gy/s) or FLASH radiotherapy (FLASH-RT) has gained significant interest during the last years, when compared to conv-RT (given at 2 Gy/min) due to more than 50% reduction in toxicity in healthy lung tissue of mice. Despite extensive development of the Monte Carlo (MC) codes to
FLASH-RT, the codes struggle to model accurately the chemical impact of the different pulse structures. The Monte Carlo codes have not been capable of explaining why the H2O2 yield is lower in FLASH beams relative to conv-RT beams in pure water. The goal of the project is to develop and customize gROS, a new MC tool capable of simulating the production and diffusion of ROS for various dose-rate and pulse structure deliveries of radiation dose. The gROS MC tool
will be validated via measurements done in water (H2O) of ROS, H2O2 and O2 consumption, for the various pulse structures and dose rates. The gROS Monte Carlo will be tested at the Marburg Ion-Beam Therapy Center (MIT) facility for various cell types (cancer and healthy) and for particles: electrons, protons and carbon ions. The key objectives are (1) To develop a gROS Monte Carlo tool capable of simulating production and diffusion of ROS and H2O2 for various low
(conv-RT) and ultra-high dose rate (FLASHRT) deliveries, for different pulse structures and at different oxygen concentrations within the medium; (2) To validate the gROS Monte Carlo tool based on measurements in H2O of O2 consumption and H2O2 (ROS) production for various pulse structures and at different oxygen concentrations within the medium; (3) To assess gROS estimate of ROS (H2O2) and O2 consumption by the radiation in an in-vitro 2D model of cancer and healthy cells irradiated with electrons, protons and carbon ions.

PrecisionXray (PXI) FLASH Shutter: Development of a table-top FLASH shutter system

A novel shutter is being developed jointly with PrecisionXray Inc, for allowing table-top FLASH conditions for Xray beams.

HELIOS: Development of Novel Particle Imaging Device for mixed He-C beam Imaging

Development of a novel range guided radiotherapy (RGRT) prototype to reduce toxicity in carbon ion therapy of non-small cell lung carcinoma (NSCLC), by invivo monitoring of the delivered dose to a moving tumor. The RGRT approach is based on a carbon beam with mixed-in helium ions, resulting in helium ions exiting the patient due to their longer range at same energy per nucleon. The exiting helium ions will allow for in-vivo and real-time monitoring of the carbon Bragg peak within the patient with 2mm accuracy, reducing the amount of healthy tissue that is irradiated. This will reduce patient toxicity and allow for improved tumor control.