The Spanish Nuclear Safety Council (CSN) demands a Radiation Protection (RP) study for the commissioning and operating authorization of the BeamPro 250 cyclotron at Valdecilla Hospital (HUMV). In response, the Physics Institute of Cantabria (IFCA) has developed a Geant4-based simulation tool called BUNSHI. Given the machine's geometry and anticipated annual workload, this tool accurately...
Neutrons are a highly penetrating type of radiation that can contribute significantly to the total absorbed dose in the human body. As a result, the monitoring of neutron dose rates is crucial to asses the risk of harm to workers, patients, and the public. Commercial portable neutron detectors, also known as ambient neutron dosimeters, are typically used for this purpose. However, there are...
In recent years, there has been a growing interest in laser-driven ion accelerators as a potential alternative to conventional accelerators for certain applications [1], mainly because of their smaller footprint and cost-effectiveness. A particularly promising application is the production of radionuclides of interest for medical imaging and therapy, via nuclear reactions such as...
Proton therapy requires precise knowledge of the patient's anatomy to guarantee an accurate dose delivery [1]. X-ray computed tomography (CT) images are used nowadays to calculate the relative stopping power (RSP) needed for proton therapy treatment planning [2]. Recent studies indicate that tomographic imaging using protons has the potential to provide a more accurate and direct measurement...
El fraccionamiento espacial de la dosis en radioterapia utilizado desde los inicios de la práctica clínica, sobre todo como tratamiento paliativo, está ganando protagonismo en la investigación de nuevas técnicas terapéuticas. Aprovechando las instalaciones de investigación de los grandes aceleradores, se comenzó a probar una variante de microhaces de fotones, encontrando resultados muy...
This work is part of an interdisciplinary research that joins the area of electromagnetic metamaterials and the area of magnetic resonance imaging for medical imaging. Ultra-high field magnetic resonance imaging systems provide an increased signal-to-noise ratio and resolution in comparison with high field systems, and the only drawback of ultra-high field systems is the inherent inhomogeneity...
En la presentación se describirán las líneas de investigación en protonterapia seguidas en el Centro Quirónsalud desde su puesta en marcha hasta la actualidad, además de dar una visión general de la actividad investigadora presente y de las líneas futuras a desarrollar en el centro.
Hadron Therapy has advantages with respect to conventional radiotherapy because of the maximization of the dose at the Bragg peak. As a drawback, and because of different systematic uncertainty sources, a quasi-real time monitoring for ion-range verification is required to reduce safety margins and thus enhance its potential benefits. Two of the most promising methodologies for in-room...
Proton therapy is a radiation treatment that targets tumoral cancers more precisely than conventional radiotherapy. This is because most of the dose is deposited near the end of the proton range at the Bragg Peak. However, different factors such as gas regions in the body, patient movement, or short-term physiological changes can produce deviations in the dose deposition. In turn, this may...
Compton camera imaging is currently under active investigation in the field of medical physics, with researchers exploring its potential for various applications. The IRIS group at IFIC-Valencia has assembled the MACACO III Compton camera prototype, equipped with three detector planes housing LaBr3 crystals coupled to silicon photomultiplier arrays. This technology aims to accurately determine...
En las últimas décadas hemos presenciado un amplio despliegue de sistemas de imagen in vivo que buscan brindar una visión multiparamétrica del tejido que responda a la gran complejidad biológica que caracteriza a varias de sus enfermedades más complejas. Cuando se habla de imagen in vivo multimodal, una pregunta que se plantea con frecuencia es si la adquisición simultánea de información...
Total-Body Positron Emission Tomography (TB-PET) technology and designs have become very popular in recent years. The advantages of these systems are many, pinpointing the high sensitivity achieved by their long axial FOV and eventually TOF, and the capabilities to simultaneously study the kinetics of multiple organs. Most of TB-PET designs and implementations are based on LYSO crystal pixels...
Positron range (PR) is one of the most important sources of resolution degradation in Positron Emission Tomography (PET). Despite that, most PET reconstruction software do not provide a specific accurate PR correction (PRC) for radionuclides with large PR such as 68Ga (including only a PRC for 18F in water), which impacts the accuracy of the studies. We recently developed Deep-PRC, a fast and...
Radionuclides are widely applied in different medical techniques for treatment and diagnosis. The success of the treatments and imaging, as well as dose minimisation to healthy tissue depend, among other things, on the decay characteristics of the radionuclide in use. This includes the different particles and radiation emitted, the emission energies and the emission probabilities. These are...
Simulations of acquisitions in medical imaging techniques such as SPECT, PET, CT, Ultrasound, etc. is a fundamental tool in medical physics research. One of the important aspects of the simulation procedure is the use of the most realistic numerical models of the human body possible. In this regard, it is very helpful for these models to be segmentated in tissues and organs so that specific...
A fine control of DNA metabolism is needed in order to ensure genomic stability, which is compromised in cancer cells. Proton Beam Therapy (PBT) is considered the most precise and less invasive form of radiation therapy available nowadays for cancer treatment and it is particularly important for paediatric cases involving brain tumours. However, the detailed biological response triggered by...
During recent years the relevance of dose rate, in addition to total dose, has been recognized to understand the response of biological systems to ionizing radiation. Particle sources based on ultra-intense laser-plasma interactions offer unique conditions to apply instantaneous dose rates orders of magnitude larger than classical accelerators. We present an ongoing research program on...
El uso de la nanotecnología ha revolucionado el mundo de la medicina y está cambiando la forma en que se combaten y se tratan varias enfermedades. Se utilizan nano-sensores para diagnóstico, nano-partículas para administrar medicamentos o nano-dispositivos para regenerar tejido dañado. Desde hace más de una década también se estudia el uso combinado de nano-partículas y radiaciones en terapias...
To evaluate the impact of various radiation types on biological damage, the Relative Biological Effectiveness (RBE) is defined as the ratio of doses required to produce a given biological response (endpoint) between the radiation source under study and a reference radiation type, typically photons. To potentially account for this in clinical practice, phenomenological and mechanistic models...
Radiopharmaceutical therapy (RPT) is a novel modality of oncology treatments that uses radiolabeled agents affine to biomolecules overexpressed in tumor cell environments. RPT has the potential to improve outcomes for oncologic patients with distant metastases compared to external radiation therapies. This is due to its ability to target specifically cancerous cells while sparing healthy...
The efficacy of radiation therapy in oncological treatment depends on multiple interrelated physical, chemical, and biological effects. Agent-based computational models have emerged as invaluable tools for elucidating these intricate interactions, although existing models predominantly rely on absorbed dose as the sole metric for predicting tumor response. Mechanistic models that incorporate...
The IRIS group at IFIC is testing a Compton camera for the visualization of the radiopharmaceutical in the patients body in targeted radionuclide therapy (TRT) assessment.
The prototye, MACACO III, is composed of three LaBr3 monolithic scintillator crystals coupled to SiPMs arrays, and it employs the ASIC VATA64HDR16 driven by the AliVATA data acquisition board for the readout. To enhance the...
Background and purpose: Transarterial radioembolization (TARE) procedures treat liver tumors by injecting radioactive microspheres into the hepatic artery. Currently, there is a critical need to optimize TARE towards personalized dosimetry. This is crucial to transition TARE to a first-line treatment for unresectable liver tumors. To this aim, we present a novel MIcrosphere DOSimetry (MIDOS)...
Introducción: La dermatitis (DR) es una de las manifestaciones del efecto de la radiación sobre la piel. Su evaluación se realiza mediante puntuaciones subjetivas, siguiendo la escala RTOG (Radiation Therapy Oncology Group). Estas evaluaciones se ven comprometidas por variaciones intra e Interevaluador [1,2].
La termografía infrarroja (TI) y las imágenes de perfusión de láser Doppler...
A precise determination of the dose locally delivered is of interest in multiple fields. In the case of radiotherapy, the measurement of the radiation dose ensures that the prescribed dose is properly delivered to the patient at the targeted location. Radiochromic films (RCFs) are currently the gold‒standard (passive) detectors for the measurement of dose distribution in radiology and...
Around 40 % of people surviving cancer do so because of radiotherapy. For improving this statistic, treatments based on hadron radiotherapy (HT) are allowing a better protection of the organs at risk by conforming the dose around the tumor target [1]. Nevertheless, some toxicities have recently been reported, being hypothesized that they can be due to the fact that hadrons deliver higher...
Proton therapy is one of the radiotherapy options currently available, which has significant advantages over conventional photon therapy. In order to assess the beam dose delivered to the patients at the cellular level during the hadrontherapy treatments, the Instituto de Microelectrónica de Barcelona (IMB-CNM) has designed and manufactured a new generation of silicon microdosimeters. The...
Silicon Carbide (SiC) is a radiation hard wide bandgap semiconductor, which makes it an interesting alternative for radiation detection applications such as radiotherapy instrumentation. Reducing the amount of metal over the active can positively affect the accuracy of the measurement.
The first SiC diodes with epitaxial graphene contacts were produced at IMB-CNM for radiation detection....
Introduction
Geant4 is a Monte Carlo toolkit widely used in bio-medical applications. As such, validation and performance monitoring focused on physics quantities relevant to this domain are of crucial need for the community. To respond to these needs, we developed G4-Med, a fully automated benchmarking tool and regression testing suite of Geant4 for relevant use cases in the bio-medical...
Introduction
The Fortran Monte Carlo code PENELOPE is widely used in radiation therapy physics as it implements the most reliable interaction models of electron, positron and gamma currently available for general purpose radiation transport codes. The transport of charged particles is modeled with a class-II algorithm in which “hard” interactions are sampled from the relevant restricted...
The processes involved in the passage of radiation through matter is of great interest in medical radiation physics among other areas. Monte Carlo codes are widely used in research fields such as micro/nanodosimetry and computational radiobiology, which demand an accurate modelling of the interaction cross sections in liquid water and other materials of interest. In Geant4-DNA, the physical...
The use of energetic ions in radiotherapy, including protons, has several advantages when compared with conventional treatments. The great targeting precision of ion beams comes from their reduced angular scattering, as well as the fact that they deposit the main part of their energy at the end of their trajectories, giving place to the depth-dose curve known as the Bragg peak. These facts...
Magnetic Resonance Imaging (MRI) of hard tissues is challenging due to the short lifetime and low strength of their resonance signals, due to strong spin-spin couplings and proton escarcity. Thus, the impact of MRI on some dental applications continues to be minor compared to X-rays techniques [1]. However, the latter employ ionizing radiation and only detect hard tissues.
MRI pulse...
Magnetic resonance imaging (MRI) is an essential tool for the diagnosis and treatment of numerous health conditions. However, its use is limited to a small fraction of potential patients due to its high cost and lack of portability. Low-field (< 0.3 T), cheap and light MRI systems are now starting to become a valuable complement to standard MRI [1]. At the MRILab we have developed an extremity...
Los sistemas de reconocimiento de la actividad humana (HAR) suelen utilizar datos inerciales recogidos con acelerómetros para modelar actividades de locomoción sencillas (correr, andar, subir y bajar escaleras, etc.). Es decir: el objetivo de los sistemas HAR es clasificar qué tipo de movimiento ha realizado el usuario. Sin embargo, estos desplazamientos pueden ser más complejos. Tal es el...
The main challenge in radiotherapy is to deposit a high enough (curative) dose in the tumor while risk organs remain at tolerable doses. Nevertheless, delivering higher doses are limited by radiation-induced toxicities in the healthy tissues surrounding tumor. A promising approach that is facing this issue is the FLASH therapy [2], which delivers ultra-high dose-rate (UHDR) (≥40Gy/s), i.e.,...
Introduction
The practice of radiation oncology has undergone a substantial improvement in all the stages of the radiotherapy process. However, the progress in our understanding of radiobiological processes has fallen behind. Take for instance FLASH therapy, whose underlying biological mechanisms still remain unknown [1]. An improvement of the accuracy, availability, and reproducibility of...
Purpose
FLASH radiotherapy (RT) is a promising technique in radiotherapy, where ultra-high dose rates (>40 Gy/s) have demonstrated, in in-vitro and animal studies, a protective effect on healthy tissues, while maintaining isoefficacy with conventional (CONV) RT in treating tumors. We performed several biological essays with proton beams at FLASH vs CONV dose rates, using healthy lung...
Objetivo:
El descubrimiento del efecto FLASH, o el aumento potencial de la ventana terapéutica de la radioterapia de alta tasa, ha traído consigo la necesidad de desarrollar instalaciones donde poder llevar a cabo experimentos a tasas suficientemente altas (>40Gy/s). Dado que en una instalación de protonterapia clínica, como el IBA proteusOne de Quironsalud, no es posible alcanzar tasas FLASH...
Recently, the use of ultra-high dose rates (FLASH) in radiation treatments has emerged as a new promising modality, where a pulsated ultra-high dose rate (>40 Gy/s) is delivered in comparison to conventional radiation therapy (~0.05 Gy/s). FLASH radiotherapy has demonstrated an unprecedented ability to reduce healthy tissue toxicity while maintaining tumor control, as shown in several in vivo...
