Jacobo Guiu-Souto

• PhD in Physics
• Medical Physics Resident at Complejo Hospitalario Universitario de Santiago

Purpose: To obtain individualized internal doses with a Monte Carlo method in patients undergoing diagnostic FCH-PET studies and to compare such doses with the MIRD method calculations. Methods: A patient cohort of 17 males were imaged after intravenous administration of a mean FCH activity of 244.3 MBq. The resulting PET/CT images were processed i...

Pharmacokinetic modeling of the radiopharmaceuticals used in molecular radiotherapy is an important step towards accurate radiation dosimetry of such therapies. In this paper, we present a pharmacokinetic model for CLR1404, a phospholipid ether analog that, labeled with ¹²⁴I/¹³¹I, has emerged as a promising theranostic agent. We follow a systematic...

Purpose To obtain individualized internal doses with a Monte Carlo (MC) method in patients undergoing diagnostic [18F]FCH‐PET studies and to compare such doses with the MIRD method calculations. Methods A patient cohort of 17 males were imaged after intravenous administration of a mean [18F]FCH activity of 244.3 MBq. The resulting PET/CT images we...

The linear-quadratic (LQ) model to describe the survival of irradiated cells may be the most frequently used biomathematical model in radiotherapy. There has been an intense debate on the mechanistic origin of the LQ model. An interesting approach is that of obtaining LQ-like behavior from kinetic models, systems of differential equations that mode...

Positron emission tomography (PET) is the gold standard of functional imaging, and it is widely used in oncology, neurology, and cardiology. The determination of the absorbed dose in patients undergoing PET is important from the point of view of the radiological protection of the patient (absorbed doses are associated with cancer risk induction), e...

The linear-quadratic (LQ) model to describe the survival of irradiated cells may be the most frequently used biomathematical model in radiotherapy. There has been an intense debate on the mechanistic origin of the LQ model. An interesting approach is that of obtaining LQ-like behavior from kinetic models, systems of differential equations that mode...

Purpose The purpose of this work is to calculate individualized dose distributions in patients undergoing ¹⁸F‐FDG PET/CT studies through a methodology based on full Monte Carlo (MC) simulations and PET/CT patient images, and to compare such values with those obtained by employing nonindividualized phantom‐based methods. Methods We developed a MC‐b...

h3> There is increasing evidence that high doses of radiotherapy, like those delivered in stereotactic body radiotherapy (SBRT), trigger indirect mechanisms of cell death. Such effect seems to be two-fold. High doses may trigger an immune response and may cause vascular damage, leading to cell starvation and death. Development of mathematical resp...

Nowadays therapies involving radioiodine (I-131) represents 84% of the total metabolic treatments in Europe, according to the last report of the European Association of Nuclear Medicine (EANM) in relation to treatment planning for molecular radiotherapy. Last recommendations of the European Council, i.e. 2013/59/Euroatom, mandates that metabolic tr...

Purpose: To present a novel 2041 liquid-filled ionization chamber array for high-resolution verification of radiotherapy treatments. Materials and methods: The prototype has 2041 ionization chambers of 2.5×2.5 mm2area filled with isooctane. The detection elements are arranged in a central square grid of 43×43, totally covering an area of 107.5×1...

In this study we have characterized the learning curve of percutaneous nephrolithotomy procedures over 301 cases for six years. Different surrogate parameters of clinical expertise have been used, such as dose area product, total procedure time, fluoroscopy time and personal equivalent doses. In addition, two different endourologists have been moni...

Understanding and predicting the evolution of competing languages is a topic of high interest in a world with more than 6000 languages competing in a highly connected environment. We consider a reasonable mathematical model describing a situation of competition between two languages and analyse the effect of the speakers' connectivity (i.e. social...

The last recommendations of the International Commission on Radiological Protection for eye lens dose suggest an important reduction on the radiation limits associated with early and late tissue reactions. The aim of this work is to quantify and optimize the eye lens dose associated to nurse staff during positron emission tomography (PET) procedure...

The effect of centrifugal forces is analyzed in a pattern-forming reaction-diffusion system. Numerical simulations conducted on the appropriate extension of the Oregonator model for the Belousov-Zhabotinsky reaction show a great variety of dynamical behaviors in such a system. In general, the system exhibits an anisotropy that results in new types...

Constantly acting centrifugal forces on Turing pattern forming systems have been observed to induce orientation and wavelength changes on Turing structures. Here, we will consider a periodic modulation of such centrifugal forces and their effects on pattern formation. Depending on the oscillation period the system exhibits a wide variety of station...

Self-organized patterns are sensitive to microscopic external perturbations that modify the diffusion process. We find that Turing instability formed in a compartmented medium, a Belousov–Zhabotinski–aerosol-OT micelle reaction, responds sensitively to a change in the diffusion process. In order to modify the diffusion mechanism, we apply a centrif...

Turing structures appear naturally and they are demonstrated under different spatial configurations such as stripes and spots as well as mixed states. The traditional tool to characterize these patterns is the Fourier transformation, which accounts for the spatial wavelength, but it fails to discriminate among different spatial configurations or mi...

Studies of Turing instability in a reactive fluid, known as BZ-AOT microemulsion, under external harmonic vibration, show modifications on pattern formation. The characteristics of the reactor and forcing prevent flows to occur, and therefore the transport phenomena can only be due to microscopic diffusion. In order to understand this problem, we c...

The effects of volume fraction modulations on a Belousov-Zhabotinsky reaction catalyzed by the photosensitive Ru(bpy)(3)(+2) confined in an AOT microemulsion system are analyzed. Kinetic observables such as the induction time or the initial oscillation period demonstrate two different types of correlation with the volume fraction depending on wheth...

We study, theoretically and experimentally, the dynamical response of macroscopic Turing patterns to a mechanical periodic forcing which implies a sinusoidal modulation of gravity. Theoretical predictions indicate that the extra energy, due to the forcing, modifies the diffusion coefficient at a microscopic level, producing changes in the Turing do...