Minimally Invasive Treatment for Lumbar Disc Herniation: A Matched Comparison Between Tubular Microdiscectomy and Percutaneous Endoscopic Lumbar Discectomy.

Background and objectives Discectomy for lumbar disc herniation is the most common spinal surgical procedure. Technological advances have led to the emergence of minimally invasive surgical approaches such as tubular microdiscectomy (TMD) and percutaneous endoscopic lumbar discectomy (PELD). The purpose of this study was to compare the clinical outcomes of PELD to those of TMD at one-year follow-up. Materials and methods This observational registry-based (Spine Tango) cohort study included patients with symptomatic lumbar disc herniation submitted to PELD or TMD. The inclusion criteria were patients who underwent minimally invasive lumbar discectomy (PELD or TMD), patients who attended a follow-up after a minimum of 12 months post surgery, and valid pre- and postoperative questionaries. The primary endpoint was defined as the difference between pre- and postoperative Core Outcome Measures Index (COMI) for the back. The matching was based on a 1:1 nearest neighbor matching without replacement. Results A total of 109 patients were included in this study. Propensity score matching (PSM) was performed achieving 86 patients in the matched sample. Regarding COMI improvement, we found no significant difference between the PELD and TMD groups (paired t-test: estimate, -0.23; standard error, 0.6; p=0.7), and we also did not find any significant difference between groups concerning Oswestry Disability Index (ODI) and EuroQol 5 Dimension (EQ-5D). Medication usage and return to work were similar among the matched groups. Conclusions PELD is a technique that minimizes tissue damage achieving good clinical outcomes similar to TMD. This was observed one year after surgery from patient-reported outcome measures (PROMs) that measured pain improvement, disability, and quality of life.

Medical staff monitoring in interventional cardiology: over apron dosemeter placement based on measurements and simulations.

Interventional cardiology is characterized by high radiation exposure for both the patient and the operator. Adequate shielding and monitoring of the operator are fundamental to comply with radiation protection principles. In a previous work, the effect on the dose of the dosemeter position on the chest was studied. In this paper, the investigation has been completed, employing an anthropomorphic thorax phantom, equipped with arms. Although there are differences between the Monte Carlo simulations and the measurements, similar trends are observed, showing that the reduction in dose, due to the arms, is between 20 and 60%, compared with the situation without arms. For that reason, considering a dosemeter placed on the chest, the upper position, which is the least affected by the arms, should be preferred while the extreme lateral position, near the armpit, should be avoided.

Antioxidant activity, cytotoxicity, phenolic content, and phytochemical composition of Pithecellobium Diversifolium benth: a pilot study / Atividade antioxidante, citotóxica, conteúdo fenólico e composição fitoquímica de Pithecellobium Diversifolium benth: um estudo piloto / Actividad antioxidante, citotóxica, contenido fenólico y composición fitoquímica de Pithecellobium Diversifolium benth: un estudio piloto

Species of Pithecellobium (Fabaceae) are used in traditional medicine to treat diabetes, cough, bronchitis, and inflammation. This study aims to evaluate the content and determine the antioxidant activity, phenolic compounds content, and cytotoxicity of the extract and the fractions of Pithecellobium diversifolium. This is unprecedented research with an exotic species from the Caatinga, northeastern Brazil, using High-performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (HPLC-ESI-MS). The MeOH fractions of leaves and stem barks showed a high content of flavonoids (198.1 ± 106.50 and 542.7 ± 2.52 mg EqQ/g). The CH2Cl2 fraction of peels showed a high content of total phenolic compounds (516.7 ± 3.00 mg EqAG /g). The DPPH test showed that the CH2Cl2 fraction (leaves) held an EC50 of 0.08 ± 0.02, a higher value than that observed for the standards used in the test­Butylated hydroxyanisole (BHA), Butylated hydroxytoluene (BHT), and ascorbic acid. The AcOEt and MeOH fractions of peels presented moderate cytotoxicity with values below 500 µg/mL. The MeOH fraction of leaves showed seven major compounds: myricetin, quercetin, quercetin-arabinofuranoside, apigenin-triglycosides, and apigenin-diglucoside, being the last three unpublished in studies involving the genus. The tests conducted in this study show the potential of P. diversifolium as a promising source of biomolecules with therapeutic applicability.

Espécies de Pithecellobium (Fabaceae) são usadas na medicina tradicional para tratar diabetes, tosse, bronquite e inflamação. Este estudo teve como objetivo avaliar o teor e determinar a atividade antioxidante, o teor de compostos fenólicos e a citotoxicidade do extrato e das frações de Pithecellobium diversifolium, uma pesquisa inédita com uma espécie exótica da Caatinga do Nordeste do Brasil, utilizando a instrumentação Clae-IES. As frações MeOH das folhas e cascas do caule apresentaram alto teor de flavonoides (198,1 ± 106,50 e 542,7 ± 2,52 mg EqQ/g). A fração CH2Cl2 das cascas apresentou um elevado teor de compostos fenólicos totais (516,7 ± 3,00 mg EqAG/g). O teste DPPH mostrou que a fração CH2Cl2 (folhas) apresentou um EC50 de 0,08 ± 0,02, valor superior ao observado para os padrões utilizados no teste ­ Butil hidroxianisol (BHA), Butil hidroxitolueno (BHT) e ácido ascórbico. As frações AcOEt e MeOH das cascas apresentaram citotoxicidade moderada com valores inferiores a 500 µg/mL. A fração MeOH das folhas apresentou sete compostos majoritários: miricetina, quercetina, quercetina-arabinofuranosídeo, apigenina-triglicosídeos e apigenina-diglucosídeo, sendo os três últimos inéditos em estudos envolvendo o gênero. Os testes realizados demonstram o potencial de P. diversifolium, uma promissora fonte de biomoléculas com aplicabilidade terapêutica.

Las especies de Pithecellobium (Fabaceae) se utilizan en la medicina tradicional para tratar diabetes, tos, bronquitis e inflamación. Este estudio tuvo como objetivo evaluar el contenido y determinar la actividad antioxidante, el contenido de compuestos fenólicos y la citotoxicidad del extracto y de las fracciones de Pithecellobium diversifolium, un estudio inédito con una especie exótica de la Caatinga de la región Nordeste de Brasil, que utilizó la instrumentación HPLC-ESI. Las fracciones MeOH de hojas y cortezas de tallo mostraron un alto contenido de flavonoides (198,1 ± 106,50 y 542,7 ± 2,52 mg EqQ/g). La fracción CH2Cl2 de las cortezas presentó un alto contenido de compuestos fenólicos totales (516,7 ± 3,00 mg EqAG/g). El ensayo DPPH mostró que la fracción CH2Cl2 (hojas) tenía EC50 de 0,08 ± 0,02, valor superior a lo observado para los estándares utilizados en el ensayo ­Butilhidroxianisol (BHA), butilhidroxitolueno (BHT) y ácido ascórbico. Las fracciones AcOEt y MeOH de las cortezas presentaron una citotoxicidad moderada con valores inferiores a 500 µ g/mL. La fracción MeOH de las hojas contiene siete compuestos principales: miricetina, quercetina, quercetina-arabinofuranosido, apigenina-triglucósidos y apigenina-diglucósido, de los cuales los tres últimos son inéditos en estudios sobre el género. Las pruebas realizadas demuestran el potencial de P. diversifolium, una fuente prometedora de biomoléculas con aplicabilidad terapéutica.

Acute toxicity and antitumor potential of 1,3,4-trisubstituted-1,2,3-triazole dhmtAc-loaded liposomes on a triple-negative breast cancer model.

For the first time, compounds developed from the 1,2,3-triazole scaffold were evaluated as novel drugs to treat triple-negative breast cancer (TNBC). Four organic salts were idealized as nonclassical bioisosteres of miltefosine, which is used in the topical treatment for skin metastasizing breast carcinoma. Among them, derivative dhmtAc displayed better solubility and higher cytotoxicity against the human breast adenocarcinoma cell line and mouse 4T1 cell lines, which are representatives of TNBC. In vitro assays revealed that dhmtAc interferes with cell integrity, confirmed by lactate dehydogenase leakage. Due to its human peripheral blood mononuclear cell (PBMC) toxicity, dhmtAc in vivo studies were carried out with the drug incorporated in a long-circulating and pH-sensitive liposome (SpHL-dhmtAc), and the acute toxicity in BALB/c mice was determined. Free dhmtAc displayed cardiac and pulmonary toxicity after the systemic administration of 5 mg/kg doses. On the other hand, SpHL-dhmtAc displayed no toxicity at 20 mg/kg. The in vivo antitumor effect of SpHL-dhmtAc was investigated using the 4T1 heterotopic murine model. Intravenous administration of SpHL-dhmtAc reduced the tumor volume and weight, without interfering with the body weight, compared with the control group and the dhmtAc free form. The incorporation of the triazole compound in the liposome allowed the demonstration of its anticancer potential. These findings evidenced 1,3,4-trisubstituted-1,2,3-triazole as a promising scaffold for the development of novel drugs with applicability for the treatment of patients with TNBC.

Endoscopic treatment of spondylodiscitis: systematic review.

BACKGROUND: Spondylodiscitis is a severe condition where standalone antibiotic therapy resolves most cases. In refractory infections, open surgery may aid with infection debulking. However, significant morbidity can occur. Nowadays, endoscopic approaches are emerging as an alternative. However, until now, only small-scale studies exist. Being so, we carried the first systematic review on spondylodiscitis endoscopic debridement indications, technique details, and outcomes. METHODS: Search for all English written original studies approaching the spondylodiscitis endoscopic treatment was performed using PubMed and EBSCO host. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and a pre-specified protocol was registered at PROSPERO (CRD42020183657). RESULTS: Fourteen studies involving 342 participants were included for analysis. Data overall quality was fair. Indications for the endoscopic approach were poorly defined. The most consensual indication was refractory infection to conservative treatment. Spinal instability or neurological deficits were common exclusion criteria. All authors described similar techniques, and despite the frequent severe co-morbidities, procedure morbidity was low. Re-interventions were common. Microorganism identification varied from 54.2 to 90.4%. Treatment failure among studies ranged from 0 to 33%. Pain, functional status, and neurological deficits had satisfactory improvement after procedures. CONCLUSIONS: The endoscopic debridement of spondylodiscitis seems to be an effective and safe approach for refractory spondylodiscitis. A novel approach with initial endoscopic infection debulking and antibiotic therapy could improve the success of spondylodiscitis treatment.

Case report: Rare convexity meningeal chondroma mimicking a meningioma.

BACKGROUND: Intracranial chondromas account for 0.2-0.3% of all intracranial neoplastic lesions and less than a quarter arise in the convexity or falx. Despite its benign nature, exceedingly rare malignant transformations exist. The misdiagnosis with meningiomas is frequent and may be related with chondromas' similar insidious clinical presentation and imaging features. Standalone surgery is advised and complete resection provides the definitive treatment. CASE DESCRIPTION: A 44-year-old female presents with insidious headache, visual disturbances, and papilledema. The imaging studies were compatible with frontal parasagittal meningioma. Surgery revealed a meningeal based mass, mostly avascular and with a well-demarked surgical plane from the brain parenchyma. Complete resection with meningeal margins was achieved and the histopathologic examination revealed a chondroma. The patient symptoms subsided and no surgical complications existed. CONCLUSION: Intracranial convexity chondromas constitute a rare differential diagnosis for meningiomas. The present case reinforces the current scarce data and serves as reminder for clinicians diagnosing and treating intracranial tumors.

Characterization of proteinuria in treated and untreated dogs naturally infected with Leishmania sp

ABSTRACT: In the search for an early biomarker of renal injury, this study aimed to determine the urinary protein profile of dogs with leishmaniasis without treatment and treated as determined by Brazilian legislation. The identification of proteinuria, its classification and the circumstances in which it takes place instigated this study. For this, 30 dogs from an outpatient clinic at a Veterinary Hospital in Belo Horizonte were evaluated. All animals underwent clinical and laboratory tests, which included renal biomarkers. The proteins were characterized using the SDS-page electrophoresis technique, and thus, a urinary protein profile was developed comparing patients considered clinically healthy with dogs infected with leishmaniasis that were under treatment and with untreated infected dogs. The results showed that the hematological and biochemical parameters showed similar behavior between the groups of healthy dogs and dogs with leishmaniasis treated, however a very heterogeneous pattern of urinary proteins can be observed and differed between healthy animals and animals with leishmaniasis, as well as between treated and untreated animals. The results suggest that the classification of proteinuria can be a tool that helps in the staging of animals infected with L. infantum and can differentiate them as to the severity of existing kidney injuries.

RESUMO: Na busca por um biomarcador precoce de injúria renal, este trabalho teve como objetivo determinar o perfil proteico urinário de cães infectados com leishmaniose sem tratamento e tratados conforme determina a legislação brasileira. A identificação da proteinúria, sua classificação e as circunstâncias em que ocorrem instigaram este estudo. Para tanto, foram avaliados 30 cães oriundos do atendimento clínico ambulatorial de um Hospital Veterinário em Belo Horizonte. Todos os animais passaram por exame clínico e laboratorial, que incluíram biomarcadores renais. As proteínas foram caracterizadas através da técnica de eletroforese por SDS-PAGE, e assim, foi elaborado um perfil proteico urinário comparando pacientes considerados clinicamente hígidos, com cães infectados por Leishmania (L.) infantum e que estavam sob tratamento e cães infectados não tratados. Os resultados demonstraram que os parâmetros hematológicos e bioquímicos apresentaram comportamento semelhante entre os grupos de cães hígidos e de cães infectados com L. infantum tratados, entretanto um padrão muito heterogêneo de proteínas urinárias pode ser observado e diferiu entre animais hígidos e animais com leishmaniose, assim como entre os animais tratados e não tratados. Os resultados sugerem que a classificação da proteinúria pode ser uma ferramenta que auxilia no estadiamento de animais infectados por L. infantum podendo diferenciá-los quanto à gravidade de lesões renais existentes.

Characterization of proteinuria in treated and untreated dogs naturally infected with Leishmania sp / Caracterização da proteinúria de cães tratados e não tratados, naturalmente infectados com Leishmania sp

In the search for an early biomarker of renal injury, this study aimed to determine the urinary protein profile of dogs with leishmaniasis without treatment and treated as determined by Brazilian legislation. The identification of proteinuria, its classification and the circumstances in which it takes place instigated this study. For this, 30 dogs from an outpatient clinic at a Veterinary Hospital in Belo Horizonte were evaluated. All animals underwent clinical and laboratory tests, which included renal biomarkers. The proteins were characterized using the SDS-page electrophoresis technique, and thus, a urinary protein profile was developed comparing patients considered clinically healthy with dogs infected with leishmaniasis that were under treatment and with untreated infected dogs. The results showed that the hematological and biochemical parameters showed similar behavior between the groups of healthy dogs and dogs with leishmaniasis treated, however a very heterogeneous pattern of urinary proteins can be observed and differed between healthy animals and animals with leishmaniasis, as well as between treated and untreated animals. The results suggest that the classification of proteinuria can be a tool that helps in the staging of animals infected with L. infantum and can differentiate them as to the severity of existing kidney injuries.(AU)

Na busca por um biomarcador precoce de injúria renal, este trabalho teve como objetivo determinar o perfil proteico urinário de cães infectados com leishmaniose sem tratamento e tratados conforme determina a legislação brasileira. A identificação da proteinúria, sua classificação e as circunstâncias em que ocorrem instigaram este estudo. Para tanto, foram avaliados 30 cães oriundos do atendimento clínico ambulatorial de um Hospital Veterinário em Belo Horizonte. Todos os animais passaram por exame clínico e laboratorial, que incluíram biomarcadores renais. As proteínas foram caracterizadas através da técnica de eletroforese por SDS-PAGE, e assim, foi elaborado um perfil proteico urinário comparando pacientes considerados clinicamente hígidos, com cães infectados por Leishmania (L.) infantum e que estavam sob tratamento e cães infectados não tratados. Os resultados demonstraram que os parâmetros hematológicos e bioquímicos apresentaram comportamento semelhante entre os grupos de cães hígidos e de cães infectados com L. infantum tratados, entretanto um padrão muito heterogêneo de proteínas urinárias pode ser observado e diferiu entre animais hígidos e animais com leishmaniose, assim como entre os animais tratados e não tratados. Os resultados sugerem que a classificação da proteinúria pode ser uma ferramenta que auxilia no estadiamento de animais infectados por L. infantum podendo diferenciá-los quanto à gravidade de lesões renais existentes.(AU)

Absorbed dose in the operator's brain in interventional radiology practices: evaluation through KAP value conversion factors.

In order to address the recent concerns over a possible increasing in brain tumour mortality among interventional radiologists and cardiologist, this work evaluated the exposure conditions of the operator's brain during interventional procedures using Monte Carlo simulations with anthropomorphic phantoms. The absorbed doses in several predefined segments of the operator's brain were estimated in a typical interventional radiology irradiation scenario. The doses were normalized to the KAP values simulated for ten X-ray beam qualities and four projections (PA, RAO 25°, LAO 25° and CRA 25°). For the interventional radiology scenario, because of the position of the operator, no difference was found in the exposure between the left and right regions of the brain for the first operator. However, for the second operator standing at a farer distance from the tube, the exposure of the left part of the brain is up to two times higher than that of the right part. The results are in agreement with dose measurements reported in the literature. The conversion factors, obtained as the absorbed dose per KAP, can be used to obtain a first estimate of the exposure of the brain of the operators during interventional procedures.

A spontaneous cervical epidural hematoma mimicking a stroke - A case report.

BACKGROUND: A spontaneous cervical epidural hematoma (SCEH) is a rare occurrence. It usually presents with quadriparesis, but it may present with hemiparesis or hemiplegia and can easily be misdiagnosed as stroke. We present a case of stroke mimicking SCEH with hemiparesis worsened after tissue plasminogen activator therapy (tPA) followed by emergency cervical decompression laminectomy. CASE DESCRIPTION: A 63-year-old female presented to the emergency department with sudden onset of posterior neck and left shoulder pain with the right side hemiparesis. On neurological examination, the patient had motor power of the right upper and lower limb of 2/5 Medical Research Council, and her whole left extremities were intact. Her medical history was unremarkable for trauma, hemorrhagic diathesis, or anticoagulation therapy. A head computed tomography was ordered ruling out intracranial hemorrhage. Assuming an acute ischemic stroke as the most likely diagnosis, alteplase (tPA) was administered 3 h after symptoms onset, however without any improvement in patient symptoms. A cervical magnetic resonance was performed revealing a right paramedian epidural mass-like lesion between C3-C6. The patient underwent cervical laminectomy C3-C6 with evacuation of epidural hematoma with significant clinical status improvement after surgery. CONCLUSION: tPA treatment is frequently used as first-line therapy for acute ischemic stroke. Therefore, physicians should be aware of the potential for the SCEH in patients presenting with hemiparesis, as tPA administration may increase cervical hematoma leading to clinical deterioration. With this case, we intended to warn about SCEH as a rare but possible entity, since its early recognition and prompt clinical intervention may improve neurological outcomes.

Performance Analysis of Geiger-Müller and Cadmium Zinc Telluride Sensors Envisaging Airborne Radiological Monitoring in NORM Sites.

Radiological monitoring is fundamental for compliance with radiological protection policies in the aftermath of radiological events, such as nuclear accidents, terrorism, and out-of-commission uranium mines. An effective strategy for radiation monitoring is to use radiation detectors coupled with Unmanned Aerial Vehicles (UAVs), enabling for quicker surveillance of large areas without involving the need of human presence in the target area. The main aim of this study was to formulate the parameters for a UAV flight strategy in preparation for future field measurements using Geiger-Muller Counters (GMC) and Cadmium Zinc Telluride (CZT) spectrometers. As a proof of concept, the prepared flight strategy will be used to survey out-of-commission uranium mines in northern Portugal. Procedures to assure the calibration of the CZT and verification of the GMCs were conducted, as well as a sensitivity analysis of the sensors considering different acquisition times, distance to source, and detector response time. This article reports specific parameters, such as UAV distance to ground, time of exposition, speed, and the methodology to perform the identification and calculate the activity of possible radioactive sources. An effective flight strategy is also presented, aiming to use radiation detectors coupled with UAVs to undertake extensive monitoring of areas with enhanced levels of environmental radiation, which is of prime importance due to the lasting hazardous effects of enhanced environmental radiation in the nearby ecosystem and population.

Past and present work practices of European interventional cardiologists in the context of radiation protection of the eye lens-results of the EURALOC study.

This paper investigates over five decades of work practices in interventional cardiology, with an emphasis on radiation protection. The analysis is based on data from more than 400 cardiologists from various European countries recruited for a EURALOC study and collected in the period from 2014 to 2016. Information on the types of procedures performed and their annual mean number, fluoroscopy time, access site choice, x-ray units and radiation protection means used was collected using an occupational questionnaire. Based on the specific European data, changes in each parameter have been analysed over decades, while country-specific data analysis has allowed us to determine the differences in local practices. In particular, based on the collected data, the typical workload of a European cardiologist working in a haemodynamic room and an electrophysiology room was specified for various types of procedures. The results showed that when working in a haemodynamic room, a transparent ceiling-suspended lead shield or lead glasses are necessary in order to remain below the recommended eye lens dose limit of 20 mSv. Moreover, the analysis revealed that new, more complex cardiac procedures such as chronic total occlusion, valvuloplasty and pulmonary vein isolation for atrial fibrillation ablation might contribute substantially to annual doses, although they are relatively rarely performed. The results revealed that considerable progress has been made in the use of radiation protection tools. While their use in electrophysiology procedures is not generic, the situation in haemodynamic procedures is rather encouraging, as ceiling-suspended shields are used in 90% of cases, while the combination of ceiling shield and lead glasses is noted in more than 40% of the procedures. However, we find that still 7% of haemodynamic procedures are performed without any radiation protection tools.

Monte Carlo study of the scattered radiation field near the eyes of the operator in interventional procedures.

Interventional radiology and cardiology guarantee high benefits for patients, but are known to be associated with a high level of radiation exposure of medical staff. The recently suggested decrease of the annual dose limit for the eye lens, from 150 to 20 mSv, caused a need for a reconsideration of practices ensuring sufficient protection for the lens of the eyes of medical staff. In such context the study of the scattered radiation around the operator's head could help in finding the best solutions to be adopted for the ceiling-suspended shield and lead glasses in the most common situations in interventional practices. MCNPX Monte Carlo code was employed with anthropomorphic mathematical phantoms to simulate interventional practice projections. For each projection the effect of changing selected parameters on the evaluated scattered radiation towards the operator's head has been calculated. The variety of modelled situations provides plentiful material regarding the spatial distribution of the scattered radiation, useful to improve eye lens radiation protection, such as the following:  (a) Glasses, which provide shielding from both lateral and bottom-up scattered radiation, can reduce by ten times the exposure to the most exposed eyes;  (b) The ceiling-suspended shield offers valuable protection, but such effectiveness can diminish by 90% if the shielding is not correctly positioned;  (c) The transition from femoral to radial access usually intensifies the scattered radiation toward the operator head (a factor of 1.5 for AP projection), but for RAO projections, a reduction of the order by two to three times, in the case of radial access, can be seen, due to the protection provided by the image receptor. The detailed fluence outcomes show that there is a preferential direction of the impinging scattered radiation that should be considered when radiation protection options are evaluated or when a dedicated eye lens dosemeter is used for monitoring.

Dosimetric effect of tissue heterogeneity for (125)I prostate implants.

AIM: To use Monte Carlo (MC) together with voxel phantoms to analyze the tissue heterogeneity effect in the dose distributions and equivalent uniform dose (EUD) for (125)I prostate implants. BACKGROUND: Dose distribution calculations in low dose-rate brachytherapy are based on the dose deposition around a single source in a water phantom. This formalism does not take into account tissue heterogeneities, interseed attenuation, or finite patient dimensions effects. Tissue composition is especially important due to the photoelectric effect. MATERIALS AND METHODS: The computed tomographies (CT) of two patients with prostate cancer were used to create voxel phantoms for the MC simulations. An elemental composition and density were assigned to each structure. Densities of the prostate, vesicles, rectum and bladder were determined through the CT electronic densities of 100 patients. The same simulations were performed considering the same phantom as pure water. Results were compared via dose-volume histograms and EUD for the prostate and rectum. RESULTS: The mean absorbed doses presented deviations of 3.3-4.0% for the prostate and of 2.3-4.9% for the rectum, when comparing calculations in water with calculations in the heterogeneous phantom. In the calculations in water, the prostate D 90 was overestimated by 2.8-3.9% and the rectum D 0.1cc resulted in dose differences of 6-8%. The EUD resulted in an overestimation of 3.5-3.7% for the prostate and of 7.7-8.3% for the rectum. CONCLUSIONS: The deposited dose was consistently overestimated for the simulation in water. In order to increase the accuracy in the determination of dose distributions, especially around the rectum, the introduction of the model-based algorithms is recommended.

Tissue composition and density impact on the clinical parameters for (125)I prostate implants dosimetry.

The MCNPX code was used to calculate the TG-43U1 recommended parameters in water and prostate tissue in order to quantify the dosimetric impact in 30 patients treated with (125)I prostate implants when replacing the TG-43U1 formalism parameters calculated in water by a prostate-like medium in the planning system (PS) and to evaluate the uncertainties associated with Monte Carlo (MC) calculations. The prostate density was obtained from the CT of 100 patients with prostate cancer. The deviations between our results for water and the TG-43U1 consensus dataset values were -2.6% for prostate V100, -13.0% for V150, and -5.8% for D90; -2.0% for rectum V100, and -5.1% for D0.1; -5.0% for urethra D10, and -5.1% for D30. The same differences between our water and prostate results were all under 0.3%. Uncertainties estimations were up to 2.9% for the gL(r) function, 13.4% for the F(r,θ) function and 7.0% for Λ, mainly due to seed geometry uncertainties. Uncertainties in extracting the TG-43U1 parameters in the MC simulations as well as in the literature comparison are of the same order of magnitude as the differences between dose distributions computed for water and prostate-like medium. The selection of the parameters for the PS should be done carefully, as it may considerably affect the dose distributions. The seeds internal geometry uncertainties are a major limiting factor in the MC parameters deduction.

Human exposure to indoor radon: a survey in the region of Guarda, Portugal.

Radon ((222)Rn) is a radioactive gas, abundant in granitic areas, such as the city of Guarda at the northeast of Portugal. This gas is recognised as a carcinogenic agent, being appointed by the World Health Organization as the second leading cause of lung cancer after tobacco smoke. Therefore, the knowledge of radon concentrations inside the houses (where people stay longer) is important from the point of view of radiological protection. The main goal of this study was to assess the radon concentration in an area previously identified with a potentially high level of residential radon. The radon concentration was measured using CR-39 detectors, exposed for a period of 2 months in 185 dwellings in the Guarda region. The radon concentration in studied dwellings, ranged between 75 and 7640 Bq m(-3), with a geometric mean of 640 Bq m(-3) and an arithmetic mean of 1078 Bq m(-3). Based on a local winter-summer radon concentration variation model, these values would correspond to an annual average concentration of 860 Bq m(-3). Several factors contribute to this large dispersion, the main one being the exact location of housing construction in relation to the geochemical nature of the soil and others the predominant building material and ventilation. Based on the obtained results an average annual effective dose of 15 mSv y(-1) is estimated, well above the average previously estimated for Portugal.

Estimation of the collective dose in the Portuguese population due to medical procedures in 2010.

In a wide range of medical fields, technological advancements have led to an increase in the average collective dose in national populations worldwide. Periodic estimations of the average collective population dose due to medical exposure is, therefore of utmost importance, and is now mandatory in countries within the European Union (article 12 of EURATOM directive 97/43). Presented in this work is a report on the estimation of the collective dose in the Portuguese population due to nuclear medicine diagnostic procedures and the Top 20 diagnostic radiology examinations, which represent the 20 exams that contribute the most to the total collective dose in diagnostic radiology and interventional procedures in Europe. This work involved the collaboration of a multidisciplinary taskforce comprising representatives of all major Portuguese stakeholders (universities, research institutions, public and private healthcare providers, administrative services of the National Healthcare System, scientific and professional associations and private service providers). This allowed us to gather a comprehensive amount of data necessary for a robust estimation of the collective effective dose to the Portuguese population. The methodology used for data collection and dose estimation was based on European Commission recommendations, as this work was performed in the framework of the European wide Dose Datamed II project. This is the first study estimating the collective dose for the population in Portugal, considering such a wide national coverage and range of procedures and consisting of important baseline reference data. The taskforce intends to continue developing periodic collective dose estimations in the future. The estimated annual average effective dose for the Portuguese population was of 0.080±0.017 mSv caput(-1) for nuclear medicine exams and of 0.96±0.68 mSv caput(-1) for the Top 20 diagnostic radiology exams.