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1.
Ned Tijdschr Tandheelkd ; 131(5): 201-208, 2024 May.
Artigo em Holandês | MEDLINE | ID: mdl-38715532

RESUMO

Growth disturbances of the temporomandibular Joint are characterized by mandibular asymmetry, sometimes with secondary maxillar disturbances. Although the clinical symptoms are sometimes quite severe, patients usually have no pain. There are several growth disturbances, but in this article we discuss three particular causes of facial asymmetry, namely hemimandibular growth defects; overdevelopment, underdevelopment and neoplasms of the mandibular joint. Hemimandibular overdevelopment (hyperplasia) is a growth disorder characterized by progressive asymmetry of the mandibula. Hemimandibular hypoplasia, on the other hand, is a growth disorder involving underdevelopment of the condyle mandibulae due to impingement of the growth center and ankylosing. A pronounced asymmetrical face can cause aesthetic problems and always requires diagnostics, because in addition to the hyperplasia and hypoplasia mentioned above, other causes can explain the asymmetry such as, for example, an osteoarthritis or even a tumor emanating from the base of the skull, mandibula or soft tissues.


Assuntos
Assimetria Facial , Transtornos da Articulação Temporomandibular , Articulação Temporomandibular , Humanos , Transtornos da Articulação Temporomandibular/diagnóstico , Transtornos da Articulação Temporomandibular/etiologia , Transtornos da Articulação Temporomandibular/terapia , Assimetria Facial/diagnóstico , Assimetria Facial/etiologia , Assimetria Facial/terapia , Mandíbula/anormalidades , Hiperplasia/diagnóstico
2.
Ned Tijdschr Tandheelkd ; 131(5): 191-200, 2024 May.
Artigo em Holandês | MEDLINE | ID: mdl-38715531

RESUMO

An internal derangement of the temporomandibular joint is described as a deviation in the position or shape of the joint tissues. Such a change is only functionally manifest if it interferes with smooth movements of the jaw joint. There are a number of internal derangements associated with jaw movements in which popping jaw joint sounds can occur. Examples are an anteriorly or posteriorly displaced disc and hypermobility of the condylar head. Although most internal derangements are harmless and only cause minor discomfort to patients, disc displacements can in some cases develop into a clinical problem, for example when there is a limitation of mouth opening (so-called closed lock) or an inability to close the mouth (so-called open lock). Most patients with these conditions do not require any or only conservative treatment.


Assuntos
Transtornos da Articulação Temporomandibular , Humanos , Articulação Temporomandibular/fisiologia , Articulação Temporomandibular/fisiopatologia , Amplitude de Movimento Articular/fisiologia , Instabilidade Articular/diagnóstico , Luxações Articulares/etiologia , Luxações Articulares/terapia , Luxações Articulares/diagnóstico
3.
ACS Appl Nano Mater ; 6(2): 1315-1324, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-37789828

RESUMO

Extravasation of circulating tumor cells (CTCs) from the vasculature is a key step in cancer metastasis. CTCs bind to cell adhesion molecules (CAMs) expressed by endothelial cells (ECs) for flow arrest prior to extravasation. While a number of EC-expressed CAMs have been implicated in facilitating CTC binding, this work investigated the efficacy of inhibiting cancer cell binding to human lung microvascular ECs via antibody blocking of E-selectin using antibody-functionalized gold nanoshells (NS). The antibody-functionalized gold NS were synthesized using both directional and non-directional antibody conjugation techniques with variations in synthesis parameters (linker length, amount of passivating agents, and ratio of antibodies to NS) to gain a better understanding of these properties on the resultant hydrodynamic diameter, zeta potential, and antibody loading density. We quantified the ability of E-selectin antibody-functionalized NS to bind human lung microvascular endothelial cells (HMVEC-Ls) under non-inflamed and inflamed (TNF-α) conditions to inhibit binding of triple-negative MDA-MB-231s. E-selectin-targeted NS prepared using non-directional conjugation had higher antibody loading than those prepared via directional conjugation, resulting in the conjugates having similar overall binding to HMVEC-Ls at a given antibody concentration. E-selectin-targeted NS reduced MDA-MB-231 binding to HMVEC-Ls by up to 41% as determined using an in vitro binding assay. These results provide useful insights into the characteristics of antibody-functionalized NS prepared under different conditions while also demonstrating proof of concept that these conjugates hold potential to inhibit CTC binding to ECs, a critical step in extravasation during metastasis.

4.
Ned Tijdschr Tandheelkd ; 130(10): 409-414, 2023 Oct.
Artigo em Holandês | MEDLINE | ID: mdl-37814835

RESUMO

Subgingival restorations are problematic due to reduced visibility at the preparation margins, humidity (saliva, crevicular fluid and/or blood), problems with taking impressions (digital or analogue) and problems with the application of a rubber dam. Solutions, such as the use of a surgical microscope, retraction cord and Teflon tape, are available. Since modern dentistry largely relies upon adhesive techniques with hydrophobic materials, these require a clean and dry working area. One solution is to place the preparation margin supragingivally. This can be done in three ways: a local build-up using a direct composite restoration, a surgical clinical crown lengthening or an extrusion (orthodontic or surgical). Since in practice only a small part is usually located subgingivally, placing a direct composite restoration is often sufficient. The term Deep Margin Elevation is generally used in the international English-language literature for this approach. If the area located subgingivally is larger, then techniques like crown lengthening and extrusion might be better.


Assuntos
Coroas , Adaptação Marginal Dentária , Humanos , Resinas Compostas/química , Restauração Dentária Permanente/métodos
5.
Ned Tijdschr Tandheelkd ; 130(10): 423-429, 2023 Oct.
Artigo em Holandês | MEDLINE | ID: mdl-37814837

RESUMO

Unfortunately, accidents do happen. Dentoalveolar injury to the front teeth resulting from trauma can sometimes be so problematic that an (adhesive) restoration seems almost impossible to make, let alone saving the tooth. In this contribution the case of a 17-year-old patient whose upper incisor suffered severe dentoalveolar trauma in a traffic accident is presented. His upper incisor was fractured deeply subgingivally, at bone level, and at first glance, appeared to be lost. Surgical extrusion, however, in this patient represents a full alternative to a prosthetic solution, such as a dental implant.


Assuntos
Implantes Dentários , Fraturas dos Dentes , Humanos , Adolescente , Fraturas dos Dentes/cirurgia , Incisivo/lesões
6.
Phys Rev Lett ; 131(4): 043603, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37566828

RESUMO

We report the levitation of a superconducting lead-tin sphere with 100 µm diameter (corresponding to a mass of 5.6 µg) in a static magnetic trap formed by two coils in an anti-Helmholtz configuration, with adjustable resonance frequencies up to 240 Hz. The center-of-mass motion of the sphere is monitored magnetically using a dc superconducting quantum interference device as well as optically and exhibits quality factors of up to 2.6×10^{7}. We also demonstrate 3D magnetic feedback control of the motion of the sphere. The setup is housed in a dilution refrigerator operating at 15 mK. By implementing a cryogenic vibration isolation system, we can attenuate environmental vibrations at 200 Hz by approximately 7 orders of magnitude. The combination of low temperature, large mass, and high quality factor provides a promising platform for testing quantum physics in previously unexplored regimes with high mass and long coherence times.

7.
Int J Oral Maxillofac Surg ; 52(5): 595-603, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36117007

RESUMO

Arthrocentesis for arthralgia of the temporomandibular joint (TMJ) is often only indicated when conservative, non-surgical interventions have failed. However, performing arthrocentesis as initial therapy may facilitate earlier and better recuperation of the joint. The aim of this study was to assess the efficacy of this therapy with a long-term follow-up. Eighty-four patients were randomly allocated to receive either arthrocentesis as initial treatment (n = 41) or non-surgical intervention (n = 43). Pain (100-mm visual analogue scale, VAS) and mandibular function impairment questionnaire scores (MFIQ, 0-100) were recorded at 3, 12, and 26 weeks, and ≥ 5 years (median 6.2, interquartile range 5.6-7.4 years). Univariable analyses were performed and linear mixed-effect models were constructed. Patients in the arthrocentesis group experienced significantly lower TMJ arthralgia compared to those treated non-surgically (pain during movement: -10.23 mm (95% confidence interval -17.86; -2.60); pain at rest: - 8.39 mm (95% confidence interval -13.70; -3.08)), while mandibular function remained similar in the two groups (MFIQ -2.41 (95% confidence interval -8.61; 3.78)). Of the final sample, 10 patients (10/39, 26%) in the non-surgical intervention group and two patients (2/34, 6%) in the arthrocentesis group received additional treatment during follow-up. Thus, initial treatment with arthrocentesis reduced TMJ arthralgia more efficaciously than non-surgical intervention in the long term, while maintaining similar mandibular function.


Assuntos
Artrocentese , Transtornos da Articulação Temporomandibular , Humanos , Seguimentos , Transtornos da Articulação Temporomandibular/terapia , Resultado do Tratamento , Articulação Temporomandibular , Artralgia/terapia , Dor , Amplitude de Movimento Articular
8.
Sci Adv ; 7(13)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33762336

RESUMO

Behavioral responsiveness to external stimulation is shaped by context. We studied how sensory information can be contextualized, by examining light-evoked locomotor responsiveness of Drosophila relative to time of day. We found that light elicits an acute increase in locomotion (startle) that is modulated in a time-of-day-dependent manner: Startle is potentiated during the nighttime, when light is unexpected, but is suppressed during the daytime. The internal daytime-nighttime context is generated by two interconnected and functionally opposing populations of circadian neurons-LNvs generating the daytime state and DN1as generating the nighttime state. Switching between the two states requires daily remodeling of LNv and DN1a axons such that the maximum presynaptic area in one population coincides with the minimum in the other. We propose that a dynamic model of environmental light resides in the shifting connectivities of the LNv-DN1a circuit, which helps animals evaluate ongoing conditions and choose a behavioral response.

9.
Am J Health Promot ; 35(2): 202-213, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32945175

RESUMO

PURPOSE: Previous DPP translations in African American women have been suboptimal. This trial evaluated a community-based participatory research developed faith-based diabetes prevention program (DPP) to improve weight loss in African American women. DESIGN: This cluster randomized trial allocated churches to faith-based (FDPP) or standard (SDPP) DPP interventions. Setting. African American churches. Subjects. Eleven churches with 221 African American women (aged 48.8 ± 11.2 years, BMI = 36.7 ± 8.4) received the FDPP (n = 6) or SDPP (n = 5) intervention. INTERVENTION: FDPP incorporated 5 faith-based components, including pastor involvement, into the standard DPP curriculum. The SDPP used the standard DPP curriculum. Lay health leaders facilitated interventions at church sites. MEASURES: Weight and biometrics were collected by blinded staff at baseline, 4- and 10-months. ANALYSIS: A multilevel hierarchical regression model compared the FDPP and SDPP groups on outcomes. RESULTS: FDPP and SDPP churches significantly lost weight at 10-months (overall -2.6%, p < .01). Women in FDPP churches who attended at least 15 sessions lost an additional 6.1 pounds at 4-months compared to SDPP corresponding to a 5.8% reduction at 10-months (p < .05). Both groups had significant improvements in health behaviors and biometrics. CONCLUSIONS: Faith-based and standard DPP interventions led by lay health leaders successfully improved weight, health behaviors, and chronic disease risk. However, the faith-based DPP when fully implemented met the CDC's recommendation for weight loss for diabetes prevention in African American women.


Assuntos
Diabetes Mellitus Tipo 2 , Redução de Peso , Adulto , Negro ou Afro-Americano , Pesquisa Participativa Baseada na Comunidade , Feminino , Comportamentos Relacionados com a Saúde , Promoção da Saúde , Humanos , Pessoa de Meia-Idade
10.
Allergy ; 73(1): 64-76, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28771830

RESUMO

Regulatory approaches for allergen immunotherapy (AIT) products and the availability of high-quality AIT products are inherently linked to each other. While allergen products are available in many countries across the globe, their regulation is very heterogeneous. First, we describe the regulatory systems applicable for AIT products in the European Union (EU) and in the United States (US). For Europe, a depiction of the different types of relevant procedures, as well as the committees involved, is provided and the fundamental role of national agencies of the EU member states in this complex and unique network is highlighted. Furthermore, the regulatory agencies from Australia, Canada, Japan, Russia, and Switzerland provided information on the system implemented in their countries for the regulation of allergen products. While AIT products are commonly classified as biological medicinal products, they are made available by varying types of procedures, most commonly either by obtaining a marketing authorization or by being distributed as named patient products. Exemptions from marketing authorizations in exceptional cases, as well as import of allergen products from other countries, are additional tools applied by countries to ensure availability of needed AIT products. Several challenges for AIT products are apparent from this analysis and will require further consideration.


Assuntos
Alérgenos/imunologia , Dessensibilização Imunológica , Hipersensibilidade/imunologia , Hipersensibilidade/terapia , Alérgenos/administração & dosagem , Dessensibilização Imunológica/métodos , Europa (Continente) , Política de Saúde , Humanos , Hipersensibilidade/epidemiologia , Guias de Prática Clínica como Assunto , Estados Unidos
11.
Allergy ; 73(4): 816-826, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29150848

RESUMO

Adequate quality is essential for any medicinal product to be eligible for marketing. Quality includes verification of the identity, content and purity of a medicinal product in combination with a specified production process and its control. Allergen products derived from natural sources require particular considerations to ensure adequate quality. Here, we describe key aspects of the documentation on manufacturing and quality aspects for allergen immunotherapy products in the European Union and the United States. In some key parts, requirements in these areas are harmonized while other fields are regulated separately between both regions. Essential differences are found in the use of Reference Preparations, or the requirement to apply standardized assays for potency determination. As the types of products available are different in specific regions, regulatory guidance for such products may also be available in one specific region only, such as for allergoids in the European Union. Region-specific issues and priorities are a result of this. As allergen products derived from natural sources are inherently variable in their qualitative and quantitative composition, these products present special challenges to balance the variability and ensuring batch-to-batch consistency. Advancements in scientific knowledge on specific allergens and their role in allergic disease will consequentially find representation in future regulatory guidelines.


Assuntos
Dessensibilização Imunológica/normas , Guias de Prática Clínica como Assunto , Controle de Qualidade , Tecnologia Farmacêutica/normas , Alérgenos , Europa (Continente) , Humanos , Estados Unidos
12.
Contemp Clin Trials ; 62: 77-90, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28807739

RESUMO

Reducing obesity positively impacts diabetes and cardiovascular risk; however, evidence-based lifestyle programs, such as the diabetes prevention program (DPP), show reduced effectiveness in African American (AA) women. In addition to an attenuated response to lifestyle programs, AA women also demonstrate high rates of obesity, diabetes, and cardiovascular disease. To address these disparities, enhancements to evidence-based lifestyle programs for AA women need to be developed and evaluated with culturally relevant and rigorous study designs. This study describes a community-based participatory research (CBPR) approach to design a novel faith-enhancement to the DPP for AA women. A long-standing CBPR partnership designed the faith-enhancement from focus group data (N=64 AA adults) integrating five components: a brief pastor led sermon, memory verse, in class or take-home faith activity, promises to remember, and scripture and prayer integrated into participant curriculum and facilitator materials. The faith components were specifically linked to weekly DPP learning objectives to strategically emphasize behavioral skills with religious principles. Using a CBPR approach, the Better Me Within trial was able to enroll 12 churches, screen 333 AA women, and randomize 221 (Mage=48.8±11.2; MBMI=36.7±8.4; 52% technical or high school) after collection of objective eligibility measures. A prospective, randomized, nested by church, design will be used to evaluate the faith-enhanced DPP as compared to a standard DPP on weight, diabetes and cardiovascular risk, over a 16-week intervention and 10-month follow up. This study will provide essential data to guide enhancements to evidence-based lifestyle programs for AA women who are at high risk for chronic disease.


Assuntos
Negro ou Afro-Americano , Diabetes Mellitus Tipo 2/etnologia , Diabetes Mellitus Tipo 2/prevenção & controle , Organizações Religiosas/organização & administração , Comportamentos Relacionados com a Saúde/etnologia , Educação em Saúde/organização & administração , Adulto , Glicemia , Pressão Sanguínea , Doenças Cardiovasculares/etnologia , Pesquisa Participativa Baseada na Comunidade , Feminino , Hemoglobinas Glicadas , Humanos , Lipídeos/sangue , Pessoa de Meia-Idade , Estudos Prospectivos , Religião , Projetos de Pesquisa , Autoeficácia
13.
Clin Exp Allergy ; 47(12): 1661-1670, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28756650

RESUMO

BACKGROUND: German cockroach (GCr) allergen extracts are complex and heterogeneous products, and methods to better assess their potency and composition are needed for adequate studies of their safety and efficacy. OBJECTIVE AND METHODS: The objective of this study was to develop an assay based on liquid chromatography and multiple reaction monitoring mass spectrometry (LC-MRM MS) for rapid, accurate, and reproducible quantification of 5 allergens (Bla g 1, Bla g 2, Bla g 3, Bla g 4, and Bla g 5) in crude GCr allergen extracts. RESULTS: We first established a comprehensive peptide library of allergens from various commercial extracts as well as recombinant allergens. Peptide mapping was performed using high-resolution MS, and the peptide library was then used to identify prototypic and quantotypic peptides to proceed with MRM method development. Assay development included a systematic optimization of digestion conditions (buffer, digestion time, and trypsin concentration), chromatographic separation, and MS parameters. Robustness and suitability were assessed following ICH (Q2 [R1]) guidelines. The method is precise (RSD < 10%), linear over a wide range (r > 0.99, 0.01-1384 fmol/µL), and sensitive (LLOD and LLOQ <1 fmol/µL). Having established the parameters for LC-MRM MS, we quantified allergens from various commercial GCr extracts and showed considerable variability that may impact clinical efficacy. CONCLUSIONS AND CLINICAL RELEVANCE: Our data demonstrate that the LC-MRM MS method is valuable for absolute quantification of allergens in GCr extracts and likely has broader applicability to other complex allergen extracts. Definitive quantification provides a new standard for labelling of allergen extracts, which will inform patient care, enable personalized therapy, and enhance the efficacy of immunotherapy for environmental and food allergies.


Assuntos
Alérgenos/análise , Alérgenos/imunologia , Blattellidae/imunologia , Espectrometria de Massas , Animais , Cromatografia Líquida , Misturas Complexas/análise , Misturas Complexas/imunologia , Mapeamento de Epitopos , Humanos , Espectrometria de Massas/métodos , Biblioteca de Peptídeos , Peptídeos/análise , Peptídeos/imunologia , Reprodutibilidade dos Testes
14.
J Fish Dis ; 40(9): 1141-1153, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28026008

RESUMO

Carp (Cyprinus carpio L.) is a pest species in Australian waterways, and cyprinid herpesvirus 3 (CyHV-3) is being considered as a potential biological control (biocontrol) agent. An important consideration for any such agent is its target specificity. In this study, the susceptibility to CyHV-3 of a range of non-target species (NTS) was tested. The NTS were as follows: 13 native Australian, and one introduced, fish species; a lamprey species; a crustacean; two native amphibian species (tadpole and mature stages); two native reptilian species; chickens; and laboratory mice. Animals were exposed to 100-1000 times the approximate minimum amount of CyHV-3 required to cause disease in carp by intraperitoneal and/or bath challenge, and then examined clinically each day over the course of 28 days post-challenge. There were no clinical signs, mortalities or histological evidence consistent with a viral infection in a wide taxonomic range of NTS. Furthermore, there was no molecular evidence of infection with CyHV-3, and, in particular, all RT-PCRs for viral mRNA were negative. As a consequence, the results encourage further investigation of CyHV-3 as a potential biocontrol agent that is specific for carp.


Assuntos
Agentes de Controle Biológico/toxicidade , Carpas , Doenças dos Peixes/virologia , Infecções por Herpesviridae/veterinária , Controle Biológico de Vetores/métodos , Animais , Austrália , Crustáceos/virologia , Suscetibilidade a Doenças/veterinária , Relação Dose-Resposta a Droga , Peixes/virologia , Herpesviridae/fisiologia , Infecções por Herpesviridae/virologia , Injeções Intraperitoneais , Espécies Introduzidas , RNA Viral/análise , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Vertebrados/virologia
16.
Lett Appl Microbiol ; 61(1): 20-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25869996

RESUMO

UNLABELLED: In this study, a duplex qPCR assay was developed for the needs of the Irish fish industry to screen for the two major food-borne pathogens of fish, Listeria monocytogenes and Escherichia coli O157:H7. The assay can claim positive or negative results for two pathogens in one go in only 20 h including 16 h universal pre-enrichment and compared to traditional ISO approved plate culture methods the labour and the cost involved in testing of one sample is reduced to minimum. The highly specific genomic areas targeted for PCR amplification in the assay are the hly gene for listeriolysin O (LLO) of L. monocytogenes and the stx gene for Shiga-like toxin expressed by E. coli O157:H7. The detection limit of the assay is consistent with the consumer protection limits of 1 pg genomic DNA or 1 CFU 25 g(-1) fish meat (with enrichment) allowing the test to be considered as a substitute to standard plate culture methods. SIGNIFICANCE AND IMPACT OF THE STUDY: The study highlights a novel duplex qPCR for Listeria monocytogenes and Escherichia coli O157:H7 that could be used as an alternative to plate-based ISO or singleplex PCR methods while minimizing the costs. The assay uses rapid DNA extraction methods and locked nucleic acid probes. Sensitivity and specificity are 100 and 98·95% respectively. The potential for quantitative rage of the assay is 10(8) -10(1) CFU ml(-1) .


Assuntos
Toxinas Bacterianas/genética , Escherichia coli O157/isolamento & purificação , Microbiologia de Alimentos/métodos , Proteínas de Choque Térmico/genética , Proteínas Hemolisinas/genética , Listeria monocytogenes/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Toxinas Shiga/genética , Animais , DNA Bacteriano/genética , Escherichia coli O157/genética , Doenças dos Peixes/diagnóstico , Doenças dos Peixes/microbiologia , Pesqueiros , Irlanda , Limite de Detecção , Listeria monocytogenes/genética , Dados de Sequência Molecular , Sensibilidade e Especificidade
17.
Opt Express ; 22(20): 24497-506, 2014 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-25322025

RESUMO

We experimentally demonstrate a high-efficiency Bell state measurement for time-bin qubits that employs two superconducting nanowire single-photon detectors with short dead-times, allowing projections onto two Bell states, |ψ⁻〉 and |ψ⁺〉. Compared to previous implementations for time-bin qubits, this yields an increase in the efficiency of Bell state analysis by a factor of thirty.

19.
Opt Express ; 22(11): 12716-36, 2014 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-24921468

RESUMO

We present a detailed description of a widely applicable mathematical model for quantum key distribution (QKD) systems implementing the measurement-device-independent (MDI) protocol. The model is tested by comparing its predictions with data taken using a proof-of-principle, time-bin qubit-based QKD system in a secure laboratory environment (i.e. in a setting in which eavesdropping can be excluded). The good agreement between the predictions and the experimental data allows the model to be used to optimize mean photon numbers per attenuated laser pulse, which are used to encode quantum bits. This in turn allows optimization of secret key rates of existing MDI-QKD systems, identification of rate-limiting components, and projection of future performance. In addition, we also performed measurements over deployed fiber, showing that our system's performance is not affected by environment-induced perturbations.

20.
Technol Cancer Res Treat ; 13(5): 415-20, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24000987

RESUMO

Immobilization devices can impact not only the inter- and intra-fraction motion of the patient, but also the range uncertainty of the treatment beam in proton therapy. In order to limit additional range uncertainty, the water equivalent thickness (WET) of the immobilization device needs to be well known and accurately reflected in the calculations by the treatment planning system (TPS). The method presented here focusses on the use of a nozzle-mounted variable range shifter and precision-machined polystyrene blocks of known WET to evaluate commercial immobilization devices prior to clinical implementation. CT studies were also completed to evaluate the internal uniformity of the immobilization devices under study. Mul- tiple inserts of the kVue platform (Qfix Systems, Avondale, PA) were evaluated as part of this study. The results indicate that the inserts are largely interchangeable across a given design type and that the measured WET values agree with those generated by the TPS with a maxi- mum difference less than 1 mm. The WET of the devices, as determined by the TPS, was not impacted by CT beam hardening normally experienced during clinical use. The reproduc- ibility of the WET method was also determined to be better than ±0.02 mm. In conclusion, the testing of immobilization prior to implementation in proton therapy is essential in order to ascertain their impact on the proton treatment and the methodology described here can also be applied to other immobilization systems.


Assuntos
Terapia com Prótons/instrumentação , Restrição Física/instrumentação , Humanos , Neoplasias/radioterapia , Imagens de Fantasmas
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