Comparison of H*(10) estimations, due to neutrons and γ-rays, around FANT with two 241Am/9Be sources.

FANT (Fuente Ampliada de Neutrones Térmicos; in Spanish) is a thermal neutron irradiation facility with an extended and very uniform irradiation area, which has been developed by the Neutron Measurement Laboratory of the Energy Engineering Department at Universidad Politécnica de Madrid (LMN-UPM). In FANT, an isotopic neutron source (241Am/9Be) produces the primary neutrons. The design and facility optimization were carried out by extensive Monte Carlo calculations. In addition, Monte Carlo methods were used to evaluate the facility's performance to produce a constant and uniform thermal neutron field; these results were validated through experimental methods. FANT is designed to have two neutron sources; the objective of this work is to estimate the ambient dose equivalent due to neutrons and gamma-rays by Monte Carlo methods, and to compare these values with measured experimental doses. Thus, the performance of FANT with the two 241Am/9Be sources of LMN-UPM, with regard to the ambient dose equivalent H*(10) produced by both neutrons and photons around the facility, is analyzed in this work. The results are compared with those previously obtained in the framework of the results obtained with the LB6411 device around FANT.

Colorectal cancer survival in Manizales, Colombia, 2008-2017: a population-based study.

OBJECTIVE: To determine 5-year survival in patients with colorectal cancer (CRC) according to patient and tumor characteristics. METHODS: Longitudinal study based on incident cases of invasive CRC between 2008 and 2017 captured by the Manizales Population-based Cancer Registry (n=850). Patients were followed up to August 24th, 2021. Cause-specific survival and net survival were calculated for sociodemographic and tumor characteristics, and Cox multivariate was fitted. RESULTS: Fifty-five percent of cases occurred in women. The most frequent histological type was adenocarcinoma (78.2%). The most frequent locations were rectum (32.0%), ascending colon (16.6%), and sigmoid (16.2%). Twenty-five percent of cases were diagnosed in stage IV. There were 567 deaths due to CRC. The 5-year specific survival was 45.8% (95%CI 42.4-49.3), with independent effects for age (HR=1.83; 95%CI 1.26-2.65 age >75 years vs. <50 years) and advanced clinical stage (HR=2.5 and HR 5.7 for stages III and IV vs. stage I, respectively). Lower survival was observed in patients of medium socioeconomic status compared with higher socioeconomic status (HR=1.52; 95%CI 1.08-2.14), but not in patients of low socioeconomic status. No independent effects were observed for the health insurance regime. CONCLUSIONS: In Manizales, approximately 5 out of 10 patients with invasive CRC die in the first five years after diagnosis, with a lower survival in patients older than 75 years, from medium socioeconomic level and diagnosed in advanced clinical stages.

Estimation with Monte Carlo of thermal neutrons in the FANT, using 252Cf and 241Am/9Be neutron source.

The thermal neutron irradiation device (FANT), developed at the Neutron Measurements Laboratory of the Energy Engineering Department at Universidad Politécnica de Madrid, is a high-density polyethylene regular parallelepiped, with a rather uniform neutron fluence inside its irradiation chamber. It uses a Am95241/Be49 neutron source aiming to provide thermal neutron fluence rates. Neutron spectra and neutron fluences were estimated with Monte Carlo methods in the FANT irradiation chamber when a Cf98252 neutron source is used and were compared with the results obtained with the Am95241/Be49 source. Regardless of the neutron source, the largest contribution is due to thermal neutrons, producing also epithermal and fast neutrons. Per neutron emitted by the source, the use of Cf98252 produces a larger amount of neutrons.

Benchmarking of stray neutron fields produced by synchrocyclotrons and synchrotrons in compact protontherapy centers (CPTC) using MCNP6 Monte Carlo code.

Proton therapy is an external radiotherapy using proton beams with energies between 70 and 230 MeV to treat some type of tumours with outstanding benefits, due to its energy transfer plot. There is a growing demand of facilities taking up small spaces and Compact Proton Therapy Centers (CPTC), with one or two treatment rooms, supposing the technical response of manufacturers to this request. A large amount of stray radiation is yielded in the interaction of proton beam used in therapy, neutrons mainly, hence, optimal design of shielding and verifications must be carried out in commissioning phases. Currently, almost 50 proton centers are under construction and start up in several countries, including ten in Spain. In the present work the effectiveness of shielding in two CPTC was verified with the Monte Carlo code MCNP6 by calculating the ambient dose equivalent, H*(10) due to secondary neutrons, outside the enclosures and walls of the center. The facilities modelled were the two centers currently operating in Spain, the first, since December 2019, with a superconductor synchrocyclotron, and the second, since March 2020, with a compact synchrotron. The geometry and materials are based on dimensions proposed a priori by the vendors, therefore, the paper is focused on check the suitability of the materials and thickness of the walls of the centers. Several models of the radiation sources were simulated, starting from a conservative assumptions, followed by more realistic scenarios. In all cases, the results reached for the ambient dose equivalent, H*(10), were below 1 mSv/year, which is the legal limit considered for the public in international references. Finally, considering that the recent ICRU Report 95 proposes changes in the operational quantities, the dose outside shieldingt has been evaluated in terms of the new next area surveillance quantity, H*, known as ambient dose, in the process of implementation.

Colorectal cancer survival in Manizales, Colombia, 2008-2017: a population-based study / Supervivencia al cáncer colorrectal en Manizales, Colombia, 2008-2017: un estudio de base poblacional

ABSTRACT Objective: To determine 5-year survival in patients with colorectal cancer (CRC) according to patient and tumor characteristics. Methods: Longitudinal study based on incident cases of invasive CRC between 2008 and 2017 captured by the Manizales Population-based Cancer Registry (n=850). Patients were followed up to August 24th, 2021. Cause-specific survival and net survival were calculated for sociodemographic and tumor characteristics, and Cox multivariate was fitted. Results: Fifty-five percent of cases occurred in women. The most frequent histological type was adenocarcinoma (78.2%). The most frequent locations were rectum (32.0%), ascending colon (16.6%), and sigmoid (16.2%). Twenty-five percent of cases were diagnosed in stage IV. There were 567 deaths due to CRC. The 5-year specific survival was 45.8% (95%CI 42.4-49.3), with independent effects for age (HR=1.83; 95%CI 1.26-2.65 age >75 years vs. <50 years) and advanced clinical stage (HR=2.5 and HR 5.7 for stages III and IV vs. stage I, respectively). Lower survival was observed in patients of medium socioeconomic status compared with higher socioeconomic status (HR=1.52; 95%CI 1.08-2.14), but not in patients of low socioeconomic status. No independent effects were observed for the health insurance regime. Conclusions: In Manizales, approximately 5 out of 10 patients with invasive CRC die in the first five years after diagnosis, with a lower survival in patients older than 75 years, from medium socioeconomic level and diagnosed in advanced clinical stages.

RESUMEN Objetivo: Estimar la supervivencia a 5 años en pacientes con cáncer colorrectal (CCR) según características del paciente y del tumor. Métodos: Estudio longitudinal a partir de los casos de CCR invasivo diagnosticados entre 2008 y 2017 captados por el Registro Poblacional de Cáncer de Manizales (n=850). Se realizó seguimiento hasta el 24 de agosto de 2021. Se calculó la supervivencia causa-específica y la supervivencia neta para las características sociodemográficas y del tumor, y análisis multivariado de Cox. Resultados: El 55,5% de los casos se presentaron en mujeres. El tipo histológico más frecuente (78,2%) fue el adenocarcinoma. Las localizaciones más frecuentes fueron recto (32,0%), colon ascendente (16,6%) y sigmoides (16,2%). El 25,5% de los casos fue diagnosticado en estadio IV. Ocurrieron 567 muertes por CCR. La supervivencia específica a 5 años fue del 45,8% (IC95% 42,4-49,3), con efectos independientes para la edad (HR=1,83; IC95% 1,26-2,65 edad >75 años vs. edad <50 años) y el estadio clínico avanzado (HR=2,5 y HR 5,7 para estadios III y IV vs. estadio I). Se observó una menor supervivencia en pacientes de nivel socioeconómico medio en comparación con el grupo de mayor posición socioeconómica (HR=1,52; IC95% 1,08-2,14), pero no en los pacientes de posición socioeconómica baja. No se observaron efectos independientes para el régimen de aseguramiento en salud. Conclusiones: En Manizales, aproximadamente 5 de cada 10 pacientes con CCR invasivo fallecen en los primeros cinco años del diagnóstico, con sobrevida menor en pacientes mayores de 75 años, de nivel socioeconómico medio y diagnosticados en estadio clínico avanzado.

Comparison of PHITS2.88 and MCNP6.1 for the characterization of a LUPIN-II neutron area monitor.

The use of different nuclear data libraries and physics models can be a source of discrepancies in neutron transport simulation. Different Monte Carlo simulation toolkits can be used to characterize neutron monitors, these codes usually employ by default different nuclear data libraries and physics models. This work presents, for the first time, a comparison of MCNP and PHITS for the characterization of a LUPIN-II neutron rem-meter. The most significant discrepancies between the codes have been found around 100 MeV.

Nuclear and Radiological Emergencies: Biological Effects, Countermeasures and Biodosimetry.

Atomic and radiological crises can be caused by accidents, military activities, terrorist assaults involving atomic installations, the explosion of nuclear devices, or the utilization of concealed radiation exposure devices. Direct damage is caused when radiation interacts directly with cellular components. Indirect effects are mainly caused by the generation of reactive oxygen species due to radiolysis of water molecules. Acute and persistent oxidative stress associates to radiation-induced biological damages. Biological impacts of atomic radiation exposure can be deterministic (in a period range a posteriori of the event and because of destructive tissue/organ harm) or stochastic (irregular, for example cell mutation related pathologies and heritable infections). Potential countermeasures according to a specific scenario require considering basic issues, e.g., the type of radiation, people directly affected and first responders, range of doses received and whether the exposure or contamination has affected the total body or is partial. This review focuses on available medical countermeasures (radioprotectors, radiomitigators, radionuclide scavengers), biodosimetry (biological and biophysical techniques that can be quantitatively correlated with the magnitude of the radiation dose received), and strategies to implement the response to an accidental radiation exposure. In the case of large-scale atomic or radiological events, the most ideal choice for triage, dose assessment and victim classification, is the utilization of global biodosimetry networks, in combination with the automation of strategies based on modular platforms.

Early glomerular filtration rate changes in living kidney donors and recipients: an example of renal plasticity.

Background: In living kidney transplantation there are two different individuals, a healthy donor and a renal transplant recipient. This is an excellent human model to study factors that influence kidney function in the context of reduced renal mass and the adaptation of two comparable kidneys to different metabolic demands. Methods: We analyzed the changes in measured glomerular filtration rate (GFR, iohexol) from pretransplantation to 12 months after transplantation in 30 donor-recipient pairs. Each donor was compared with his/her recipient. We defined a priori three different groups based on GFR differences at 12 months: donor > recipient (Group A; 78 ± 8 versus 57 ± 8 mL/min), donor < recipient (Group B; 65 ± 11 versus 79 ± 11 mL/min) and donor ≈ recipient (Group C; 66 ± 7 versus 67 ± 7 mL/min). Other factors like donor/recipient mismatches in body mass index (BMI), surface area and gender were evaluated. Results: In Group A donors were mostly male and recipients were female (75% each). Donors had a higher baseline weight than their recipients. During follow-up, weight remained stable in donors but increased 7% in recipients. In Group B donors were mostly female (60%) and recipients male. At baseline, donors had a lower weight than recipients. At 12 months, weight was stable in donors but increased in recipients. In Group C donors were mostly (75%) female and recipients male. At baseline, donors had a higher BMI than their recipients. At 12 months, BMI was stable in donors but increased 14% in recipients. In multivariable analysis, higher GFR at 12 months was associated with higher baseline weight and GFR in donors and with male gender and higher baseline weight in recipients. Conclusions: Kidneys from living donors are more 'plastic' than originally thought and respond to metabolic demands and weight changes of their new host. These changes should be taken into account when assessing GFR outcomes in this population.

Application of an algebraic methodology for the combination of Berthold LB6411 and WENDI-II for neutron area monitoring in D-T neutron generators and fusion facilities.

Neutron area monitors do not often have a good adjustment of their dose response functions to the ICRP74 neutron fluence-to-H*(10) conversion function between 10 and 20 MeV. The objective of this work is to establish a methodology to combine the dose response functions of Berthold LB6411 and WENDI-II, adjusting this combined function to the ICRP74 conversion function: this combination shows an almost perfect adjustment between 0.5 and 20 MeV. Thus, this article presents an easy and cheap alternative to the recalibration in D-T generators.

A novel conceptualization in the analysis and design of passive neutron area monitors based on gold foil activation.

In the detection and measurement of neutron fields, with energies between 10 and 20 MeV, current passive neutron area monitors based on gold foil sensors usually do not have a perfect fitting of their dose response functions with the neutron fluence-to-ambient dose equivalent conversion function from ICRP74. However, apart from the radiative capture in 197Au, the common channel considered in these monitors, other nuclear reactions in 197Au can be considered to improve the fit between both functions. Therefore, this work aimed to develop a mathematical combination of response functions in passive monitors with gold foils, considering the (n, γ) and (n, 2n) channels in 197Au, to extend their response up to 20 MeV, improving their performance under neutron fields with high energies. The proposed methodology avoids introducing modifications in the original device, such as the insertion of sheets with high-Z materials, and simplifies the design and manufacturing of passive monitors, while reducing costs.

Comparison of FANT results using the ENDF/B-VII.1, JEFF-3.3 and TENDL2017 nuclear data libraries.

FANT (Fuente Ampliada de Neutrones Térmicos; in Spanish) is a thermal neutron irradiation facility with an extended and very uniform irradiation area, that has been developed by the Neutron Measurements Laboratory of the Energy Engineering Department at Universidad Politecnica de Madrid (LMN-UPM). This device is a parallelepiped box made of high-density polyethylene (HDPE), moderator material, that uses an A95241m/B49e neutron source of 111 GBq nominal activity for irradiating materials. The facility design was previously optimized, and the neutron spectra were estimated by extensive calculations with the MCNP6.1 code and carrying out experimental measurements (Bedogni et al., 2017). The facility takes advantage of the scattering reactions of neutrons with the HDPE surfaces of the chamber, where the moderation process is effective, achieving relevant thermal neutron fluence rates. The main goal of this work has been to simulate and analyse the FANT system by Monte Carlo methods using the MCNP6.1 code, employing 3 different nuclear data libraries: ENDF/B-VII.1, JEFF-3.3 and TENDL 2017. The transport of thermal neutrons in HDPE, E < 1eV, has been calculated in all the cases taking into account the thermal S (α,ß) treatment. The results achieved in this work have been compared with those previously obtained in the former development of FANT, using the MCNP6.1 code with the ENDF/B-VII.1 nuclear data, and experimental measurements. These results have shown that the JEFF-3.3 nuclear data library is the nuclear data library that provides of the best matching between the MCNP computational results, and the experimental data collected at FANT. Hence, the JEFF-3.3 nuclear data library seems to be the most correct library to design and benchmark thermal neutron activation devices.

Determination of the uncertainties associated to the use of different nuclear data libraries in the analysis of extended-range rem-meters.

In proton therapy centers stray neutron radiation of up to 230-250 MeV is yielded by (p, Xn) nuclear reactions. To monitor ambient dose in such facilities, extended-range rem-meters are needed. The aim of this project was to characterize the response of two extended-range rem-meters, WENDI-II and LUPIN-II, by Monte Carlo methods, for energies ranging from 10-9 MeV up to 230 MeV. Different nuclear data libraries (ENDF/B-VII.1, TENDL2017, TENDL2019, JEFF-3.3) have been used, determining the uncertainties associated with the application of the libraries in the calculation of the response functions of both monitors. The differences found are very significant at energies around 150-200 MeV. This is an issue for predicting by Monte Carlo methods the response of these instruments at high energies. The results point to the necessity of testing experimentally the response of rem-meters at 150 MeV-200 MeV neutron beams.

Radiation protection infrastructure-challenges in developing countries.

A special session was held in the International Radiation Protection Association (IRPA15) Congress to address the particular challenges facing developing countries regarding radiation protection infrastructure. The objective was to identify and share the key challenges facing developing countries regarding the ability to introduce and establish effective radiation protection programmes. The experiences of key international organisations (International Atomic Energy Agency, Pan American Health Organisation and World Health Organisation) that have support programmes were discussed, along with a perspective from several countries with developing programmes. The key common challenges include: governmental commitment at senior levels, with provision of the necessary resources: establishment of an independent regulatory body and related infrastructure: appropriate numbers of qualified staff in all necessary fields, including their education and training: supporting physical infrastructure, such as dosimetry and measurement equipment including calibration laboratories. In addressing these challenges the importance of support from the key international organisations was emphasised. More emphasis should be given to the application of the graded approach. The establishment of support networks at a national or regional level that allow for the sharing of experiences and resources, and that support the wellbeing of isolated professionals, is also crucial. In this aspect the support from wider professional bodies such as IRPA and established national radiation protection societies can also play a key role.

Neutron dosimetry and shielding verification in commissioning of Compact Proton Therapy Centers (CPTC) using MCNP6.2 Monte Carlo code.

Proton therapy (PT) is an external radiotherapy using proton beams with energies between 70 and 230 MeV to treat some type of tumours with outstanding benefits, due to its energy transfer plot. There is a growing demand of facilities taking up small spaces and Compact Proton Therapy Centers (CPTC), with one or two treatment rooms, supposing the technical response of manufacturers to this request. A large amount of stray radiation is produced in the interaction of protons used in therapy, neutrons mainly, hence, optimal design of shielding and verifications must be carried out in commissioning stages. Currently, almost 50 CPTC are under construction and start up in many countries, including several in Spain. In the present work, the effectiveness of shielding in a CPTC was verified with the Monte Carlo code MCNP6 by calculating the ambient dose equivalent, H*(10) due to secondary neutrons, outside the enclosures and walls of the center. The facility modelled was similar to one planned to start operating in 2019 in Spain, a CPTC, made up of a superconducting synchrocyclotron and one treatment room, with a configuration standard, shielding and width of barriers based on dimensions proposed a priori by the vendor. Therefore, the paper is focused in check the suitability of the materials and thickness of the walls of the center and develop the assessment of enclosures. Several models of the radiation sources and type of concrete in walls were simulated, starting from a conservative assumptions, followed by more realistic models. In all cases, the results were below 1 mSv/year, which is the international legal limit considered for the general public. This work is part of the project Contributions to Shielding and Dosimetry of Neutrons in Compact Proton Therapy Centers (CPTC).

Experimental characterization of FANT, a new thermal neutron source.

FANT is the acronym of Enhanced Thermal Neutron Source (Fuente Ampliada de Neutrones Térmicos, in Spanish). This is a parallelepiped box of high-density polyethylene moderator and an isotopic neutron source. The moderator has a cylindrical irradiation chamber where a rather uniform thermal neutron flux is obtained. The FANT design was previously optimized and the neutron spectra were estimated by Monte Carlo calculations with the MCNP6.1 code. To check the characteristics of the FANT thermal neutron field, measurements have been performed at the reference point inside the irradiation chamber with a Bonner sphere spectrometer holding a small 6LiI(Eu) thermal neutron detector. To unfold the neutron spectrum BUNKIUT with UTA4 response matrix and NSDann Ver 4.0 codes were used. Some issues have been found and recommendations are made about the use of large BSS inside narrow spaces, and about the capacity of NSDann code to unfold these kind of spectra. However, the results confirm that the moderation process in FANT is very effective and allows obtaining useful thermal neutron fluence rates.

Clinical characteristics of thyroid cancer in Manizales, Colombia, 2008-2015. / Características clínicas del cáncer de tiroides en Manizales, Colombia, 2008-2015.

A study was conducted to describe the cases of thyroid cancer in Manizales, Colombia. This study describes the characteristics of patients; and tumors according to size, laterality, focalization, nodal involvement, contiguous invasion, metastasis and TNM staging. A total of 672 cases were analyzed, 84.8% of which were women between 40 and 64 years of age. From the population, 34.1% were cases diagnosed in early stages and 15% of the tumors were >20 mm in size. Nodal and adjacent tissue involvement was present in 33% and 3% of the cases, respectively. Distant metastasis was documented in 1% of the cases. Papillary carcinoma was present in 82% of cases. Thyroid cancer in Manizales is more frequent in adult women. Tumor size and being at the early stages are factors that suggest improvement in early detection.

Con el objetivo de describir los casos de cáncer de tiroides en Manizales, Colombia, se realizó un estudio que describe las características de los pacientes y de los tumores según el tamaño, la lateralidad, la focalización, el compromiso ganglionar, la invasión contigua, la metástatisis y la estadificación TNM. Se analizaron 672 casos, el 84,8% de ellos fueron mujeres entre 40 y 64 años. El 34,1% de los casos fueron diagnosticados en estadios tempranos y el 15% de los tumores tuvieron un tamaño <20 mm. El compromiso ganglionar y de tejidos adyacentes estuvo presente en el 33% y el 3% de los casos, respectivamente. Se registró un 1% de metástasis a distancia. El carcinoma papilar se presentó en el 82% de los casos. El cáncer de tiroides en Manizales es más frecuente en mujeres adultas; el estadio temprano y el tamaño tumoral sugieren mejora en la detección temprana.

Analysis by Monte Carlo methods of the response of an extended-range Bonner Sphere Spectrometer.

High-energy neutrons up to 230 MeV are generated as a consequence of (p,n) nuclear reactions in proton therapy facilities. The aim of this work is to evaluate the potential extension of the UPM Bonner Sphere Spectrometer (BSS) through the use of spallation materials, for its future application to determine neutron fluence spectra in such facilities. Monte Carlo methods have been used to model the response of the actual and modified spheres with the introduction of a spallation material layer, lead or copper, analyzing their response functions. An analysis is also made of the neutron fluence spectra over the 6LiI(Eu) scintillator volume and the uncertainty that can be associated to the response functions at high energies as a consequence of the different physics models that can be applied for their analysis.

Características clínicas del cáncer de tiroides en Manizales, Colombia, 2008-2015 / Clinical characteristics of thyroid cancer in Manizales, Colombia, 2008-2015

RESUMEN Con el objetivo de describir los casos de cáncer de tiroides en Manizales, Colombia, se realizó un estudio que describe las características de los pacientes y de los tumores según el tamaño, la lateralidad, la focalización, el compromiso ganglionar, la invasión contigua, la metástatisis y la estadificación TNM. Se analizaron 672 casos, el 84,8% de ellos fueron mujeres entre 40 y 64 años. El 34,1% de los casos fueron diagnosticados en estadios tempranos y el 15% de los tumores tuvieron un tamaño <20 mm. El compromiso ganglionar y de tejidos adyacentes estuvo presente en el 33% y el 3% de los casos, respectivamente. Se registró un 1% de metástasis a distancia. El carcinoma papilar se presentó en el 82% de los casos. El cáncer de tiroides en Manizales es más frecuente en mujeres adultas; el estadio temprano y el tamaño tumoral sugieren mejora en la detección temprana.

ABSTRACT A study was conducted to describe the cases of thyroid cancer in Manizales, Colombia. This study describes the characteristics of patients; and tumors according to size, laterality, focalization, nodal involvement, contiguous invasion, metastasis and TNM staging. A total of 672 cases were analyzed, 84.8% of which were women between 40 and 64 years of age. From the population, 34.1% were cases diagnosed in early stages and 15% of the tumors were >20 mm in size. Nodal and adjacent tissue involvement was present in 33% and 3% of the cases, respectively. Distant metastasis was documented in 1% of the cases. Papillary carcinoma was present in 82% of cases. Thyroid cancer in Manizales is more frequent in adult women. Tumor size and being at the early stages are factors that suggest improvement in early detection.

Stakeholder participation in nuclear and radiological emergency preparedness and recovery in Spain: benefits and challenges of working together.

Emergency preparedness and response (EP&R) to radiological or nuclear accidents depends on many different stakeholder groups: nuclear and radiological regulators and authorities; institutions and ministries concerned by health, environment and consumption; first-line responders including the police, military, firefighters and health workers; as well as local authorities and nuclear industries. Stakeholders also include the general public, such as people living near NPPs8 or affected by previous nuclear or radiological accidents and incidents. Teachers and journalists, bloggers and other social media figures would play a key role in effective dissemination of knowledge and information. NGOs9 or civil associations/societies can also be involved in radiation monitoring and protection. The present study describes the role of different research institutions (such as CIEMAT10, UPM11 and ISGlobal12) and of the Spanish Society of Radiological Protection (SEPR) in bringing together the above-listed stakeholders in Spain to discuss EP&R and identify benefits and challenges of working together. Stakeholder opinions on EP&R, collected mainly in the framework of several European-funded projects, are provided. Remaining barriers and examples of good practices in radiation protection are discussed, as well as recommendations for improving nuclear and radiological emergency preparedness in Spain. The conclusions may be useful for other countries.

Monte Carlo characterization and benchmarking of extended range REM meters for its application in shielding and radiation area monitoring in Compact Proton Therapy Centers (CPTC).

Compact Proton Therapy Centers, CPTC, have a single treatment room, and are technologically more affordable, smaller, advanced and easier to use. From a radiological protection point of view, the leading concern in CPTC are interactions of protons with components of the facility and patients that yield a broad emission of secondary particles, mainly high-energy neutrons, up to 230 MeV, and photons. Optimal design of shielding involves theoretical assumptions in the design phase and, consequently, experimental measurements with extended range neutron detectors must be carried out in the facility during the commissioning period to verify the design, assumptions and building of the enclosures. There are almost 50 CPTC under construction and planning around the world, hence the improvement of methodologies to verify the shielding and to evaluate the dose to workers and general public in CPTC is a trending issue. The aim of this work was to evaluate and compare the response of two commercial extended range REM meters, WENDI-II and LUPIN-II, for their application in shielding verification and radiation area monitoring in CPTC facilities, by estimating the ambient dose equivalent, H*(10), through the Monte Carlo code MCNP6. The results have been compared with previous works. Likewise, the performance evaluation of these devices in continuous energy neutron field have been carried out, using the AmBe/241 neutron source of the Neutronics Hall (NH) of the Neutron Measurements Laboratory of the Energy Engineering Department of Universidad Politecnica de Madrid (LMN-UPM), through Monte Carlo simulation with the MCNP6 code and experimental measurements. The work is framed into the project Contributions to Shielding and Dosimetry of Neutrons in CPTC.