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Janus kinases (JAK) are intracellular tyrosine kinases that transduce cytokine-mediated signals to the nucleus, promoting gene expression. Cytokines play a major role in microbial sepsis, which is often associated with uncontrolled inflammation leading to death. JAK inhibitors have been used for the treatment of several autoimmune diseases by modulating immune response, but they have never been tested against microbial sepsis. Ruxolitinib is a small-molecule inhibitor of JAK1/2 proteins, which are involved in the downstream signaling pathway of the vast majority of proinflammatory and anti-inflammatory cytokines. We therefore studied the effect of ruxolitinib in a mouse model of sepsis due to Candida albicans. When ruxolitinib therapy (50 mg/kg [of body weight]/day) was started 1 day before infection, the median survival time was reduced by 3 days, the fungal loads in all organs were higher, the inflammation was significantly less, and serum tumor necrosis factor alpha (TNF-α) and interleukin 10 (IL-10) levels and IL-10/TNF-α ratios were higher than in controls. When ruxolitinib therapy (50 to 1.5 mg/kg/day) was started 1 day after infection, an inverted-U relationship was found, with 6.25 mg/kg/day prolonging median survival time by 6 days, resulting in similar fungal loads, less inflammation, and similar cytokine levels but higher IL-10/TNF-α ratios than the controls. The optimal dose of ruxolitinib controlled infection and prolonged survival with less inflammation than in control animals. Administration of JAK inhibitors may be a promising therapeutic adjunct that needs further investigation.
Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candidemia/tratamento farmacológico , Janus Quinases/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Sepse/tratamento farmacológico , Animais , Antifúngicos/administração & dosagem , Candida albicans/isolamento & purificação , Candidemia/mortalidade , Citocinas/sangue , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Inflamação/tratamento farmacológico , Inflamação/microbiologia , Camundongos Endogâmicos , Nitrilas , Inibidores de Proteínas Quinases/administração & dosagem , Pirazóis/administração & dosagem , Pirimidinas , Sepse/mortalidadeRESUMO
In this work we investigate both experimentally and theoretically the optical properties of aligned, perpendicular to the substrate, high aspect ratio (AR), plasma etched Si nanowires (SiNWs) with controlled variability. We focus on the role of imperfections in fabrication, which manifest themselves as dimensional variability of SiNW, lattice defects or positional randomization. SiNW arrays are fabricated by e-beam lithography (perfectly ordered array) or colloidal particle self-assembly (quasi-ordered array) followed by cryogenic Si plasma etching, which offers fast etch rate (up to 3 µm min(-1)) combined with clean, smooth, and controllable sidewall profile, but induces some dimensional variability on the diameters of the SiNWs. Sub-200 nm diameter SiNWs having AR as high as 37:1 are demonstrated. The total reflectance of SiNWs is below 2% in a wide range of the optical spectrum. We experimentally demonstrate improved light absorption when moving from a perfectly ordered (after e-beam lithography) to a defective and quasi-ordered (after colloidal self-assembly) SiNW array. In addition our measured reflectivity (for both ordered and quasi-ordered SiNWs) is much lower compared to the one predicted theoretically for a perfect SiNWs array, using full-electrodynamic calculations with the layer-multiple-scattering method. To explain such low reflectivity, we model the influence of disorder using the average T-matrix approximation and show that even small dimensional variability (10-20%) leads to dramatic reduction of the reflectance (matching the experimental results) and increased light trapping inside the SiNW justifying their possible application in photovoltaic devices.
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We study, by means of full-electrodynamic calculations using the layer-multiple-scattering method, the effect of diffractive coupling on the enhancement of the local electromagnetic field in periodic arrays of nanolenses consisting of three silver spheres with progressively decreasing sizes and separations. The interaction between the hot-spot modes of an isolated nanolens with the Rayleigh-Wood anomalies of the periodic lattice leads to a further enhancement of the local field intensity, which can be controlled by an appropriate choice of the geometrical parameters involved.
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We discuss the simultaneous existence of phononic and photonic band gaps in a periodic array of holes drilled in a Si membrane. We investigate in detail both the centered square lattice and the boron nitride (BN) lattice with two atoms per unit cell which include the simple square, triangular and honeycomb lattices as particular cases. We show that complete phononic and photonic band gaps can be obtained from the honeycomb lattice as well as BN lattices close to honeycomb. Otherwise, all investigated structures present the possibility of a complete phononic gap together with a photonic band gap of a given symmetry, odd or even, depending on the geometrical parameters.
Assuntos
Acústica/instrumentação , Compostos de Boro/química , Óptica e Fotônica/instrumentação , Silício/química , Cristalização , Modelos Teóricos , FótonsRESUMO
OBJECTIVE: To determine whether the position of the tension-free vaginal tape (TVT) has an effect on postoperative flow rates and voiding function in women successfully cured of urodynamic stress incontinence. METHODS: Postoperatively 72 women who had undergone TVT surgery had a transperineal ultrasound examination to assess the position of the TVT on the urethra. The tape was categorized as proximal, mid or distal urethral. The effect on voiding was assessed using the maximum flow rate (MFR) centiles corrected for voided volume and detrusor pressure at maximum flow. RESULTS: Forty-six women had distal tapes and 26 mid-urethral tapes. A tape lying on the mid urethra was associated with a fall in MFR centile (P = 0.04) while a tape lying on the distal urethra did not cause a fall in the MFR centile (P = 0.52). There was no significant change in the detrusor pressure at maximum flow between mid and distally placed tapes. CONCLUSIONS: Distally placed tapes cause less alteration in flow rates than do mid-urethrally placed tapes. This may be beneficial in certain patient groups.
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Slings Suburetrais , Uretra/fisiopatologia , Incontinência Urinária por Estresse/fisiopatologia , Micção/fisiologia , Feminino , Humanos , Pessoa de Meia-Idade , Resultado do Tratamento , Ultrassonografia , Uretra/diagnóstico por imagem , Uretra/cirurgia , Incontinência Urinária por Estresse/diagnóstico por imagem , Incontinência Urinária por Estresse/cirurgia , UrodinâmicaRESUMO
PURPOSE: Helical tomotherapy has been in clinical use for several years. One of the issues with a helical tomotherapy unit is the failure of detection of the x-ray target. In this study, we are proposing a method to detect potential failure of the x-ray target. METHODS: Currently, on-board detector data from a helical tomotherapy unit are collected and sent to TomoTherapy Inc. for comparison with the so-called gold standard for the unit. However, this is sometimes time-consuming. Furthermore, the clinical medical physicists have no access to this comparison procedure. In this study, we developed a practical method to detect target failure based on one of the monthly quality assurance (QA) procedures. The commissioning cross-plane profiles were used as the comparison baseline. Larger EDR2 film (35×43 cm) were set at source-axis distance (SAD) (85 cm) and shot with 1.5 cm solid water as build-up material and 10 cm solid water as backscattering material. Cross-plane profiles obtained from the EDR2 film were compared with the commissioning profiles. RESULTS: When the cross-plane profiles from monthly QA have 1° degree difference from the commissioning profiles, it is time that the target be changed. CONCLUSION: This method enables the clinical medical physicists to easily evaluate the target status and to help improving the quality assurance of a helical tomotherapy unit.
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Tomografia Computadorizada Espiral/métodos , Humanos , Garantia da Qualidade dos Cuidados de Saúde , Tomografia Computadorizada Espiral/normasRESUMO
PURPOSE: In this study, an experiment was devised to establish the dependency of the impact of pulse forming network (PFN) and injection current (IC) parameters on output and energy variations of helical tomotherapy (HT) on the radiation beam output and energy. METHODS: HT has unique radiation beam characteristics due to the absence of a flattening filter. As with conventional linear accelerators, the machine output and energy should be within a + or - 2% tolerance according to published studies. However, because a dose servo is not utilized in a HT unit, these parameters may drift out of the + or - 2% tolerance due to various reasons such as high machine temperatures. With this in mind, physicists and engineers must adjust certain machine parameters to reset the output and energy to within the tolerance of the commissioned baseline. Two parameters commonly adjusted are: PFN voltage (V(PFN)) and IC voltage (V(IC)). RESULTS: Results showed that the HT unit possesses different working zones defined by the V(PFN) and V(IC) parameter settings. The working zones were classified into 5 zones: 1) low dose rate zone - radiation dose rate much lower than nominal dose rate and machine cannot run due to low dose rate fault; 2) normal dose rate zone - dose rate is within tolerance of nominal dose rate and machine can run without dose rate fault; 3) dose rate failure during treatment zone - dose rate within the tolerance of the nominal dose rate however machine interrupts during treatment due to dose rate fault; 4) high dose rate zone - dose rate is higher than nominal dose rate and machine cannot run due to high dose rate fault; and 5) inoperable dose rate zone - dose rate is much higher than the nominal dose rate and machine cannot run. CONCLUSION: The results of this study may provide a quick guide for physicists to adjust their HT unit V(PFN) and V(IC) values in order to reset the radiation beam output and energy back to within the tolerance of the commissioned baseline.
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Planejamento da Radioterapia Assistida por Computador/métodos , Desenho de Equipamento , Humanos , Imagens de Fantasmas , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/instrumentação , Radioterapia de Intensidade Modulada/métodosRESUMO
A DNA dosimeter (DNAd) was previously developed that uses double-strand breaks (DSB) to measure dose. This dosimeter has been tested to measure dose in scenarios where transient-charged particle equilibrium (TCPE) has been established. The probability of double strand break (PDSBo), which is the ratio of broken double-stranded DNA (dsDNA) to the initial unbroken dsDNA in the dosimeter, was used to quantify DSBs and related to dose. The goal of this work is to produce a new technique to process and analyze the DNAd and quantify DNA-DSBs. This technique included simultaneously processing multiple DNAds and also establishing a new form to the probability of double strand break (PDSBn), which was then used to test the DNAd in a non-TCPE condition by taking beam penumbra measurements. The technique utilized a 384-well plate, and the measurements were made at the edge of a 10 × 10 cm field and compared to film measurements. During these penumbra measurements, while observing the positional differences in the higher gradient region at 4.1 and 4.55 cm from the center of the radiation field, the distance to agreement of PDSBo to film were 0.38 cm and 0.26 cm while the distance to agreement of PDSBn to film were 0.11 cm and 0.06 cm, respectively. Finally, the developed new separation technique reduced the time needed for the analysis of 25 samples from 200 min to 30 min.
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DNA/química , Quebras de DNA de Cadeia Dupla , Dosímetros de RadiaçãoRESUMO
The purpose of this study was to commission a first-of-its-kind dual-layer micro multileaf collimator (mMLC) system by using Monte Carlo dose calculations. The mMLC is attached on a Varian 600C linac. Having a lower and an upper layer of MLC leaves, this mMLC allows for field shaping in two orthogonal directions. The commissioning of the system was performed in two steps: without and with the mMLC attached on the linac. The treatment head without and with the mMLC was modeled in the BEAMnrc Monte Carlo (MC) code. The scoring planes for the phase space files were specified below the linac's secondary collimators (jaws) and above and below the mMLC. With the mMLC attached to the linac the field size was defined by the jaws as 10 x 10 cm(2), which is also the maximum possible field size that can be shaped by the mMLC. For the commissioning of the linac, several fields of various sizes were simulated and compared against ionization chamber measurements in a water phantom. Output factors for several field sizes, as well as percent depth dose curves and dose profiles for rectangular and irregular shape fields, were calculated and compared against measurements in water. Agreement between measured and calculated data was better than 1% and less than 1.0 mm in the penumbra region for open fields. With the mMLC attached, the agreement between measurements and MC calculations is within 1.0% or 1.0 mm in the penumbra region.
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Método de Monte Carlo , Radioterapia Conformacional/instrumentação , Simulação por Computador , Dosagem Radioterapêutica , Radioterapia Conformacional/métodosRESUMO
Four-dimensional (4D) radiotherapy is considered as a feasible and ideal solution to accommodate intra-fractional respiratory motion during conformal radiation therapy. With explicit inclusion of the temporal changes in anatomy during the imaging, planning, and delivery of radiotherapy, 4D treatment planning in principle provides better dose conformity. However, the clinical benefits of developing 4D treatment plans in terms of tumor control rate and normal tissue complication probability as compared to other treatment plans based on CT images of a fixed respiratory phase remains mostly unproven. The aim of our study is to comprehensively evaluate 4D treatment planning for nine lung tumor cases with both physical and biological measures using biologically effective uniform dose (D =) together with complication-free tumor control probability, P+. Based on the examined lung cancer patients and PTV margin applied, we found similar but not identical curves of DVH, and slightly different mean doses in tumor (up to 1.5%) and normal tissue in all cases when comparing 4D, P0%, and P50% plans. When it comes to biological evaluations, we did not observe definitively PTV size dependence in P+ among these nine lung cancer patients with various sizes of PTV. Moreover, it is not necessary that 4D plans would have better target coverage or higher P+ as compared to a fixed phase IMRT plan. However, on the contrary to significant deviations in P+ (up to 14.7%) observed if delivering the IMRT plan made at end-inhalation incorrectly at end-exhalation phase, we estimated the overall P+, PB, and PI for 4D composite plans that have accounted for intra-fractional respiratory motion.
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Neoplasias Pulmonares/radioterapia , Planejamento da Radioterapia Assistida por Computador , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Movimento , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada , RespiraçãoRESUMO
PURPOSE: The purpose of this project was to develop a software platform to produce a virtual fluoroscopic image as an aid for permanent prostate seed implants. MATERIALS AND METHODS: Seed location information from a pre-plan was extracted and used as input to in-house developed software to produce a virtual fluoroscopic image. In order to account for differences in patient positioning on the day of treatment, the user was given the ability to make changes to the virtual image. RESULTS: The system has been shown to work as expected for all test cases. CONCLUSION: The system allows for quick (on average less than 10 sec) generation of a virtual fluoroscopic image of the planned seed pattern. The image can be used as a verification tool to aid the physician in evaluating how close the implant is to the planned distribution throughout the procedure and enable remedial action should a large deviation be observed.
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Braquiterapia , Fluoroscopia/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Interface Usuário-Computador , Inteligência Artificial , Humanos , Masculino , Próteses e ImplantesRESUMO
PURPOSE: To determine the feasibility of using megavoltage (MV) images and digital tomosynthesis to determine the three dimensional (3D) localization of different objects. MATERIALS AND METHODS: Different phantom geometries were imaged using an electronic portal imaging device and digital tomosynthesis was used to reconstruct tomograms. These were compared with corresponding computed tomography (CT) images. RESULTS: While in-plane resolution of the tomograms was comparable as that of the CT images, definite out-of-plane (depth) localization was restricted to 5 mm. CONCLUSION: The results confirm that it is possible to perform 3D localization of objects by using digital tomosynthesis for volumetric reconstructions from individually-acquired MV-quality portal images.
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Imageamento Tridimensional , Imagens de Fantasmas , Interpretação de Imagem Radiográfica Assistida por Computador , Radioterapia Assistida por Computador/métodos , Radioterapia de Alta Energia , Radioterapia de Intensidade Modulada , Tomografia Computadorizada de Feixe Cônico/instrumentação , Estudos de Viabilidade , Radioterapia Assistida por Computador/instrumentação , Reprodutibilidade dos Testes , SoftwareRESUMO
We developed a dosimeter that measures biological damage following delivery of therapeutic beams in the form of double-strand breaks (DSBs) to DNA. The dosimeter contains DNA strands that are labeled on one end with biotin and on the other with fluorescein and attached to magnetic microbeads. Following irradiation, a magnet is used to separate broken from unbroken DNA strands. Then, fluorescence is utilized to measure the relative amount of broken DNA and determine the probability for DSB. The long-term goal for this research is to evaluate whether this type of biologically based dosimeter holds any advantages over the conventional techniques. The purpose of this work was to optimize the dosimeter fabrication and usage to enable higher precision for the long-term research goal. More specifically, the goal was to optimize the DNA dosimeter using three metrics: the response, precision, and cost per dosimeter. Six aspects of the dosimeter fabrication and usage were varied and evaluated for their effect on the metrics: (1) the type of magnetic microbeads, (2) the microbead to DNA mass ratio at attachment, (3) the type of suspension buffer used during irradiation, (4) the concentration of the DNA dosimeter during irradiation, (5) the time waited between fabrication and irradiation of the dosimeter, and (6) the time waited between irradiation and read out of the response. In brief, the best results were achieved with the dosimeter when attaching 4.2 µg of DNA with 1 mg of MyOne T1 microbeads and by suspending the microbead-connected DNA strands with 200 µl of phosphate-buffered saline for irradiation. Also, better results were achieved when waiting a day after fabrication before irradiating the dosimeter and also waiting an hour after irradiation to measure the response. This manuscript is meant to serve as guide for others who would like to replicate this DNA dose measurement technique.
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Quebras de DNA de Cadeia Dupla/efeitos da radiação , Reparo do DNA/efeitos da radiação , DNA/análise , Dosímetros de Radiação/economia , Dosímetros de Radiação/normas , DNA/genética , DNA/efeitos da radiação , HumanosRESUMO
In single-isocenter stereotactic radiosurgery/radiotherapy (SRS/SRT) intracranial applications, multiple targets are being treated concurrently, often involving non-coplanar arcs, small photon beams and steep dose gradients. In search for more rigorous quality assurance protocols, this work presents and evaluates a novel methodology for patient-specific pre-treatment plan verification, utilizing 3D printing technology. In a patient's planning CT scan, the external contour and bone structures were segmented and 3D-printed using high-density bone-mimicking material. The resulting head phantom was filled with water while a film dosimetry insert was incorporated. Patient and phantom CT image series were fused and inspected for anatomical coherence. HUs and corresponding densities were compared in several anatomical regions within the head. Furthermore, the level of patient-to-phantom dosimetric equivalence was evaluated both computationally and experimentally. A single-isocenter multi-focal SRS treatment plan was prepared, while dose distributions were calculated on both CT image series, using identical calculation parameters. Phantom- and patient-derived dose distributions were compared in terms of isolines, DVHs, dose-volume metrics and 3D gamma index (GI) analysis. The phantom was treated as if the real patient and film measurements were compared against the patient-derived calculated dose distribution. Visual inspection of the fused CT images suggests excellent geometric similarity between phantom and patient, also confirmed using similarity indices. HUs and densities agreed within one standard deviation except for the skin (modeled as 'bone') and sinuses (water-filled). GI comparison between the calculated distributions resulted in passing rates better than 97% (1%/1 mm). DVHs and dose-volume metrics were also in satisfying agreement. In addition to serving as a feasibility proof-of-concept, experimental absolute film dosimetry verified the computational study results. GI passing rates were above 90%. Results of this work suggest that employing the presented methodology, patient-equivalent phantoms (except for the skin and sinuses areas) can be produced, enabling literally patient-specific pre-treatment plan verification in intracranial applications.
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Neoplasias Encefálicas/cirurgia , Dosimetria Fotográfica/instrumentação , Imagens de Fantasmas , Impressão Tridimensional/instrumentação , Garantia da Qualidade dos Cuidados de Saúde/normas , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Algoritmos , Humanos , Radiometria/métodos , Dosagem Radioterapêutica , Tomografia Computadorizada por Raios XRESUMO
The purpose of this study was to determine whether early postoperative voiding dysfunction can be predicted before inserting a tension-free vaginal tape (TVT). Multiple parameters including demographic data, history of previous anti-incontinence surgery, anaesthetic type, operator experience, type of surgical procedure (TVT alone or combined with other prolapse surgery) and preoperative urodynamic studies were analysed by univariate analysis and stepwise multiple logistic regression. The data from 500 women were prospectively collected. Early voiding dysfunction occurred in 5.8% of women postoperatively. Using stepwise multiple logistic regression, voiding by other than a detrusor contraction (p = 0.02), preoperative pressure flow rate <15 ml/s (p = 0.04) and general anaesthesia (p = 0.02) were the only factors that predicted early postoperative voiding dysfunction. The point estimate relative risks were 5.6, 11.6 and 4.4 and the positive predicting values were 11.4%, 11.8% and 16.1%, respectively. Despite statistically significant associations with early voiding dysfunction, the positive predictive values of the identified factors remain low, limiting the accurate prediction of early voiding dysfunction.
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Slings Suburetrais/efeitos adversos , Incontinência Urinária por Estresse/diagnóstico , Incontinência Urinária por Estresse/epidemiologia , Urodinâmica , Prolapso Uterino/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Inglaterra/epidemiologia , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Risco , Incontinência Urinária por Estresse/etiologiaRESUMO
The study aimed to assess the efficacy of retropubic urethrolysis (RU) on obstructive and overactive bladder (OAB) symptoms and to assess the effect on voiding parameters in a small series of six women. Each patient had significant obstructive or OAB symptoms, and was obstructed on urodynamics. RU was performed if conservative measures, anticholinergics and urethral dilatation failed. The mean time since colposuspension was 10 years. All patients complained of poor flow, with 5/6 complaining of OAB symptoms. Postoperatively, all the women reported improved voiding. The maximum flow rate increased from a mean of 11.2 ml/s to 16.4 ml/s, with the Pdet at a maximum flow decreasing from a mean of 43.2 cm H(2)O to 34.7 cm H(2)O. The post-void residual was less than 100 ml in all six patients postoperatively. One reported improved OAB symptoms. There are variable success rates for RU reported in the literature. Careful patient selection and counselling is necessary.
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Procedimentos Cirúrgicos em Ginecologia/efeitos adversos , Complicações Pós-Operatórias/terapia , Obstrução Uretral/cirurgia , Bexiga Urinária Hiperativa/cirurgia , Incontinência Urinária por Estresse/cirurgia , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Reoperação , Obstrução Uretral/etiologia , Bexiga Urinária Hiperativa/etiologia , UrodinâmicaRESUMO
PURPOSE: To characterize a relative sensitivity or performance factor between two commercial thermoluminescent dosimeter (TLD) readers that can be used in inter comparing the thermoluminescent (TL) signals from the readers. MATERIALS AND METHODS: The measurements were made with well-characterized TLD chips, TLD-100 (LiF: Mg; Ti). For illustrative purposes, we used the Harshaw TLD-5500 and the Victoreen 2800M TLD readers available in our department. A well-calibrated 6 MV beam linear accelerator was used as the source of radiation. RESULTS: A sensitivity factor between the two readers used in the illustration was measured as 3.40 +/- 0.13 with the Harshaw TLD-5500 reader producing the superior sensitivity. In terms of measurement repeatability, we observed 2.32% +/- 1.17% reproducibility with the Victoreen 2800M TLD reader and 1.86% +/- 0.95% reproducibility with the Harshaw TLD - 5500 reader. The linearity properties of the two readers were comparable. CONCLUSION: The sensitivity factor is to be interpreted as follows: when working with multiple TLD readers, in this case two, suppose the calibration of the TLD chip was performed with one of the readers, then we can use this calibration factor when measurements are made with the other reader provided we correct for differences in sensitivity with a relative sensitivity factor. This of course is true only if the TLD reader settings used at the time of measurement are similar to those used at the time of relative sensitivity characterization. Owing to a wide range of other factors that can affect the reader sensitivity, we recommend use of a relative sensitivity factor in protection level dosimetry only in situations where inaccuracies of up to 10% are acceptable.
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Dosimetria Termoluminescente , Humanos , Reprodutibilidade dos TestesRESUMO
PURPOSE: Intensity modulated radiotherapy (IMRT) using multileaf collimators (MLC) and helical tomotherapy (HT) have become increasingly popular over the past few years. However, their clinical efficacy and effectiveness continue to be investigated. In order to provide a more thorough evaluation and comparison of treatment plans, the utilization of the biologically effective uniform dose (D) together with the complication-free tumor control probability (P(+)) are examined. MATERIALS AND METHODS: In this study, a typical case of lung cancer was investigated by developing a 3D conformal treatment plan, a linac MLC-based step-and-shoot IMRT plan and a HT plan. The 3 different treatment plans were compared based on radiobiological measures by using the P(+) index and the D concept as the common prescription point of the plans and plotting the tissue response probabilities vs. D for a range of prescription doses. RESULTS: The applied plan evaluation method showed that in this lung cancer case the MLC-based IMRT plan was best over the clinically useful dose prescription range. The 3D-conformal, MLC-based IMRT and HT treatment plans gave a P(+) of 55.4%, 72.9% and 66.9%, for a D to the internal target volume (ITV) of 57.0 Gy, 66.9 Gy and 64.0 Gy, respectively. CONCLUSION: In comparison to 3D conformal radiotherapy, both MLC based-IMRT and HT can better encompass the often large ITV required while minimizing the volume of the organs at risk receiving high dose. Taking into account the dose-response relations of the irradiated tumors and normal tissues, a radiobiological treatment plan evaluation can be performed, which may provide a closer association of the delivered treatment with the clinical outcome.
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Neoplasias Pulmonares/radioterapia , Radioterapia Conformacional/métodos , Tomografia Computadorizada Espiral/métodos , Relação Dose-Resposta à Radiação , Humanos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por ComputadorRESUMO
The purpose of this study was to evaluate and compare the accuracy of dose calculations in second check softwares (Diamond, IMSure, MuCheck, and RadCalc) against the Phillips Pinnacle3 treatment planning system. Eighteen previously treated patients' treatment planning files consisting of a total of 204 beams were exported from the Pinnacle3 TPS to each of the four second check software. Of these beams, 145 of the beams used were IMRT plans while 59 were VMAT arcs. The values were represented as a percent difference between primary and secondary calculations and used for statistical analysis. Box plots, Pearson Correlation, and Bland-Altman analysis were performed in MedCalc. The mean percent difference in calculated dose for Diamond, IMSure, MuCheck, and RadCalc from Pinnacle3 were -0.67%, 0.31%, 1.51% and -0.36%, respectively. The corresponding variances were calculated to be 0.07%, 0.13%, 0.08%, and 0.03%; and the largest percent differences were -7.9%, 9.70%, 9.39%, and 5.45%. The dose differences of each of the second check software in this study can vary considerably and VMAT plans have larger differences than IMRT. Among the four second check softwares, RadCalc values has shown a high agreement on average with low variation, and had the smallest percent range from Pinnacle3 values. The closest in average percent difference from the Pinnacle3data was the IMSure software, but suffered from significantly larger variance and percent range. The values reported by Diamond and MuCheck had significantly high percent differences with TPS values.
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Planejamento da Radioterapia Assistida por Computador/métodos , Software , Algoritmos , Humanos , Aceleradores de Partículas , Radiometria/métodos , Planejamento da Radioterapia Assistida por Computador/instrumentação , Radioterapia de Intensidade Modulada/métodosRESUMO
This is a comparative study aiming to investigate quality of life (QoL) and depression in individuals diagnosed either with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS), or genital warts (GW) and genital herpes (GH), in two healthcare settings, in the United Kingdom (UK) or in Greece (Gr). Using a matched-pairs design, two equalized patient samples with sexually transmitted infections (STI) were recruited: from UK (n=43) and from Greece (n=43). QoL was assessed with WHOQOL-HIV BREF for HIV patients and WHOQOL-STI BREF -a newly adapted instrument- for genital warts and genital herpes patients. Depressive symptomatology was measured by the Centre for Epidemiological Studies- Depression Scale (CES-D) along with sociodemographic data. Results indicate that in both country- healthcare settings, a high percentage of individuals diagnosed with any type of STI, reported considerable depressive symptomatology: 35.7% for UK and 41.5% for Greek participants respectively. Regarding QoL, participants in the Greek healthcare settings reported significantly lower scores in the environment domain, and even lower scores were reported by the GW/GH group, in comparison to HIV. Specifically, these groups indicated significantly lower values in the following WHOQOL-BREF environment facets: (i) physical safety and security, (ii) participation in and opportunities for recreation/leisure activities, (iii) home environment, (iv) accessibility and quality in health and social care, and (v) transport facilities. Regarding correlation of QoL and depression, regression analysis provided significant evidence for depression having a differential effect on WHOQOL-BREF QoL domains. Evidence of increased depressive symptomatology in both STI patient- cohorts may shed light into unmet healthcare needs that should be addressed by healthcare providers in UK and Greece respectively. Furthermore, all types of Greek STI participants reported lower QoL, particularly the GW/GH group, indicating important unmet QoL needs in the environment domain, such as health and social care accessibility and quality, or environmental and social resources, all lowering everyday QoL. The present findings may provide guidelines for tailored mental health interventions alleviating depressive symptomatology in STI patients. Provision of targeted-interventions at healthcare and social-environmental levels will contribute to QoL/ health improvement in STI patients.