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1.
Eur J Surg Oncol ; 49(12): 107100, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37918318

RESUMEN

INTRODUCTION: In view of the high therapeutic value of surgical resection for intrahepatic cholangiocarcinomas (ICC), our study addresses the question of clinical management and outcome in case of borderline resectability requiring hypertrophy induction of the future liver remnant prior to resection. METHODS: Clinical data was collected of all primary ICC cases receiving major liver resection with or without prior portal vein embolization (PVE) from a single high-volume center. PVE was performed via a percutaneous transhepatic access. Propensity score matching was performed. Perioperative morbidity was assessed as well as long-term survival with a minimum follow-up of 36 months. RESULTS: No significant difference in perioperative morbidity was seen between the PVE and the control group. For the PVE group, median OS was 28 months vs. 37 months for the control group (p = 0.418), median DFS 18 and 14 months (p = 0.703). Disease progression during hypertrophy was observed in 38% of cases. Here, OS and DFS was reduced to 18 months (p = 0.479) and 6 months (p = 0.013), respectively. In case of positive N-status or multifocal tumor (MF+) OS was also reduced (18 vs. 26 months, p = 0.033; MF+: 9 vs. 36months p = 0.013). CONCLUSION: Our results suggest that the surgical therapy in case of borderline resectability offers acceptable results with non-inferior OS rates compared to cases without preoperative hypertrophy induction and comparable oncological features. In the presence of additional risk factors (multifocal tumor, lymph node metastasis, PD during hypertrophy) the OS is notably reduced.


Asunto(s)
Neoplasias de los Conductos Biliares , Colangiocarcinoma , Embolización Terapéutica , Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/cirugía , Neoplasias Hepáticas/secundario , Vena Porta/cirugía , Colangiocarcinoma/cirugía , Embolización Terapéutica/métodos , Hepatectomía/métodos , Conductos Biliares Intrahepáticos/cirugía , Neoplasias de los Conductos Biliares/cirugía , Hipertrofia/etiología , Hipertrofia/cirugía , Resultado del Tratamiento
2.
Eur J Radiol Open ; 8: 100320, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33457469

RESUMEN

PURPOSE: Besides diagnostic imaging devices, in particular computed tomography (CT) and magnetic resonance imaging (MRI), numerous reading workstations contribute to the high energy consumption of radiological departments. It was investigated whether switching off workstations after core working hours can relevantly lower energy consumption considering both ecological and economical aspects. METHODS: Besides calculating different theoretical energy consumption scenarios, we measured power consumption of 3 workstations in our department over a 6-month period under routine working conditions and another 6-month period during which users were asked to switch off workstations after work. Staff costs arising from restarting workstations manually were calculated. RESULTS: Our approach to switching off workstations after core working hours reduced energy consumption by about 5.6 %, corresponding to an extrapolated saving of 3.2 tons in carbon dioxide (CO2) emissions and 2100.70 USD/year in electricity costs for 227 workstations. Theoretical calculations indicate that consistent automatic shutdown after core working hours could result in a potential total reduction of energy consumption of 38.6 %, equaling 22.2 tons of CO2 and 14,388.28 USD/year. However, staff costs resulting from waiting times after manually restarting workstations would amount to 36,280.02 USD/year. CONCLUSIONS: Switching off workstations after core working hours can considerably reduce energy consumption and costs, but varies with user adherence. Staff costs caused by waiting time after manually starting up workstations outweigh energy savings by far. Therefore, an energy-saving plan with automated shutdown/restart besides enabling an energy-saving mode would be the most effective way of saving both energy and costs.

4.
Ecol Appl ; 30(3): e02058, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31838775

RESUMEN

Most spatial conservation planning for wide-ranging or migratory species is constrained by poor knowledge of species' spatiotemporal dynamics and is only based on static species' ranges. However, species have substantial variation in abundance across their range and migratory species have important spatiotemporal population dynamics. With growing ecological data and advancing analytics, both of these can be estimated and incorporated into spatial conservation planning. However, there is limited information on the degree to which including this information affects conservation planning. We compared the performance of systematic conservation prioritizations for different scenarios based on varying the input species' distributions by ecological metric (abundance distributions versus range maps) and temporal sampling resolution (weekly, monthly, or quarterly). We used the example of a community of 41 species of migratory shorebirds that breed in North America, and we used eBird data to produce weekly estimates of species' abundances and ranges. Abundance distributions at a monthly or weekly resolution led to prioritizations that most efficiently protected species throughout the full annual cycle. Conversely, spatial prioritizations based on species' ranges required more sites and left most species insufficiently protected for at least part of their annual cycle. Prioritizations with only quarterly species ranges were very inefficient as they needed to target 40% of species' ranges to include 10% of populations. We highlight the high value of abundance information for spatial conservation planning, which leads to more efficient and effective spatial prioritization for conservation. Overall, we provide evidence that spatial conservation planning for wide-ranging migratory species is most robust and efficient when informed by species' abundance information from the full annual cycle.


Asunto(s)
Cruzamiento , Conservación de los Recursos Naturales , América del Norte , Dinámica Poblacional
6.
Ultraschall Med ; 37(4): 393-8, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25815457

RESUMEN

PURPOSE: To evaluate the feasibility and effectiveness of US-guided sacroiliac joint injection in the treatment of sacroiliitis in children. MATERIALS AND METHODS: This study was approved by the institutional review board and informed oral and written consent was obtained from the patients and their parents. In 13 patients (7 females and 6 males), 9 - 16 years (mean +/- std 11.39 +/-1.98), 18 sacroiliac joint (SI joint) injections were performed under US guidance. All patients suffered from severe sacroiliitis. US scanning was performed using a linear-array transducer operating at 5 - 18 MHz. Rating of the patients pain using a 0 - 10 dolorimetry scale on a visual analog score (VAS) was recorded before, immediately after and 3 months after injection to monitor severity and therapeutic response. RESULTS: Injection could be performed in all patients without complication and showed good response immediately and 3 months after the injection with a decrease of the VAS (from mean +/- std 9.44 +/- 1.097 to 3.89 +/- 3.82, p < 0.001 and to 0.56 +/- 1.097, p < 0.05, respectively). CONCLUSION: US-guided SI joint injection was feasible in all children, relatively quick and easy to perform and appeared effective in the treatment of children with sacroiliitis.


Asunto(s)
Inyecciones Intraarticulares/métodos , Articulación Sacroiliaca/efectos de los fármacos , Sacroileítis/diagnóstico por imagen , Sacroileítis/tratamiento farmacológico , Ultrasonografía Intervencional , Adolescente , Niño , Estudios de Factibilidad , Femenino , Humanos , Masculino
7.
Rofo ; 188(3): 253-8, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26529265

RESUMEN

UNLABELLED: Typically both breast and prostate cancer present as tissue with decreased elasticity. Palpation is the oldest technique of tumor detection in both organs and is based on this principle. Thus an operator can grade a palpable mass as suspicious for cancer. Strain elastography as modern ultrasound technique allows the visualization of tissue elasticity in a color coded elastogram and can be understood as technical finger. The following article shows similarities and differences of ultrasound strain elastography in the diagnosis of breast and prostate cancer. KEY POINTS: • In prostata cancer elastography, in breast cancer B-mode is the primary sonographic search modality. • The diagnostic value of the search modalities change with increasing age.• A cut-off value for a strain ratio is hard to obtain in the elastography of the prostata, because there is no stabile reference tissue in the prostata.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/fisiopatología , Diagnóstico por Imagen de Elasticidad/métodos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/fisiopatología , Ultrasonografía Mamaria/métodos , Módulo de Elasticidad , Femenino , Humanos , Aumento de la Imagen/métodos , Masculino
8.
Hum Brain Mapp ; 35(8): 3819-31, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24523262

RESUMEN

Resting-state studies conducted with stroke patients are scarce. First objective was to explore whether patients with good cognitive recovery showed differences in resting-state functional patterns of brain activity when compared to patients with poor cognitive recovery. Second objective was to determine whether such patterns were correlated with cognitive performance. Third objective was to assess the existence of prognostic factors for cognitive recovery. Eighteen right-handed stroke patients and eighteen healthy controls were included in the study. Stroke patients were divided into two groups according to their cognitive improvement observed at three months after stroke. Probabilistic independent component analysis was used to identify resting-state brain activity patterns. The analysis identified six networks: frontal, fronto-temporal, default mode network, secondary visual, parietal, and basal ganglia. Stroke patients showed significant decrease in brain activity in parietal and basal ganglia networks and a widespread increase in brain activity in the remaining ones when compared with healthy controls. When analyzed separately, patients with poor cognitive recovery (n=10) showed the same pattern as the whole stroke patient group, while patients with good cognitive recovery (n=8) showed increased activity only in the default mode network and fronto-temporal network, and decreased activity in the basal ganglia. We observe negative correlations between basal ganglia network activity and performance in Semantic Fluency test and Part A of the Trail Making Test for patients with poor cognitive recovery. A reverse pattern was observed between frontal network activity and the above mentioned tests for the same group. .


Asunto(s)
Encéfalo/fisiopatología , Cognición , Imagen por Resonancia Magnética/métodos , Recuperación de la Función , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/fisiopatología , Adulto , Anciano , Encéfalo/patología , Mapeo Encefálico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vías Nerviosas/patología , Vías Nerviosas/fisiopatología , Pruebas Neuropsicológicas , Proyectos Piloto , Pronóstico , Descanso , Índice de Severidad de la Enfermedad , Procesamiento de Señales Asistido por Computador , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/psicología
9.
Laterality ; 16(5): 620-35, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21424982

RESUMEN

There are contradictory results on lateralisation and localisation of rhythm processing. Our aim was to test whether there is a hemispheric dissociation of metric and non-metric rhythm processing. We created a non-metric rhythm stimulus without a sense of metre and we measured brain activities during passive rhythm perception. A total of 11 healthy, right-handed, native female Hungarian speakers aged 21.3 ± 1.1 were investigated by functional magnetic resonance imaging (fMRI) using a 3T MR scanner. The experimental acoustic stimulus consisted of comprehensive sentences transformed to Morse code, which represent a non-metric rhythm with irregular perceptual accent structure. Activations were found in the right hemisphere, in the posterior parts of the right-sided superior and middle temporal gyri and temporal pole as well as in the orbital part of the right inferior frontal gyrus. Additional activation appeared in the left-sided superior temporal region. Our study suggests that non-metric rhythm with irregular perceptual accents structure is confined to the right hemisphere. Furthermore, a right-lateralised fronto-temporal network extracts the continuously altering temporal structure of the non-metric rhythm.


Asunto(s)
Percepción Auditiva/fisiología , Cerebro/fisiología , Dominancia Cerebral/fisiología , Lateralidad Funcional/fisiología , Periodicidad , Percepción del Tiempo/fisiología , Estimulación Acústica/métodos , Mapeo Encefálico/métodos , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Adulto Joven
10.
Phys Rev Lett ; 98(10): 107401, 2007 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-17358564

RESUMEN

A key to ultralong electron spin memory in quantum dots (QDs) at zero magnetic field is the polarization of the nuclei, such that the electron spin is stabilized along the average nuclear magnetic field. We demonstrate that spin-polarized electrons in n-doped (In,Ga)As/GaAs QDs align the nuclear field via the hyperfine interaction. A feedback onto the electrons occurs, leading to stabilization of their polarization due to formation of a nuclear spin polaron [I. A. Merkulov, Phys. Solid State 40, 930 (1998)]. Spin depolarization of both systems is consequently greatly reduced, and spin memory of the coupled electron-nuclear spin system is retained over 0.3 sec at temperature of 2 K.

12.
Radiology ; 214(2): 591-5, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10671617

RESUMEN

The authors used a frameless stereotactic navigation system, the Vogele-Bale-Hohner head holder, and a targeting device to reproducibly position brachytherapy needles for fractionated interstitial brachytherapy in 12 patients with inoperable cancers of the head and neck. In all cases, deviations of the needle relative to the planned position were within 1-15 mm depending on the location of the tumor.


Asunto(s)
Braquiterapia , Neoplasias de Cabeza y Cuello/radioterapia , Radioterapia Asistida por Computador , Técnicas Estereotáxicas , Braquiterapia/instrumentación , Carcinoma de Células Escamosas/radioterapia , Fraccionamiento de la Dosis de Radiación , Diseño de Equipo , Estudios de Seguimiento , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Protectores Bucales , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Inducción de Remisión , Técnicas Estereotáxicas/instrumentación , Tasa de Supervivencia , Tomografía Computarizada por Rayos X
14.
Strahlenther Onkol ; 174(9): 473-7, 1998 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-9765689

RESUMEN

PURPOSE: To reach an optimal treatment result and to avoid damage to critical structures a homogeneous dose distribution in the tumor volume with a rapid decreasing dose to the surrounding structures is necessary. Fractionated interstitial brachytherapy of tumors in the ENT region employing needles depends on exact localization of the target volume during all fractions. Therefore reproducibility of positioning of the needle(s) plays an important role. MATERIAL AND METHODS: We used the ISG Viewing Wand system in combination with the Vogele-Bale-Hohner (VBH) head holder and a new targeting device. Point of entrance, pathway, and target point of the needle were planned and insertion of the needle simulated in advance. To date we have treated 7 patients with inoperable tumors in the ENT region. The actual position of the needle in the control CT was compared to the planned position. RESULTS: The accuracy of positioning of the needle depended on the location of the tumor. In a patient with a recurrent retroorbital adenocarcinoma the mean accuracy was 1 mm. Due to soft tissue displacement in the neck region and the resulting necessity to readjust the targeting device the needle was placed with a mean deviation of 15 mm between the planned and the actual position. CONCLUSIONS: Computer-assisted frameless stereotactic interstitial brachytherapy allows for precise, reproducible and preplanned insertion of hollow needles into target structures closely adherent to the surrounding tissue, thus avoiding damage of neighbouring structures. This technique is of great advantage in treating deeply seated tumors which are fixed to bony structures, especially at the skull base. Inaccuracy in the neck region caused by soft tissue shift requires improvement of the immobilization in this region.


Asunto(s)
Braquiterapia/instrumentación , Radiocirugia/instrumentación , Terapia Asistida por Computador/instrumentación , Braquiterapia/métodos , Braquiterapia/tendencias , Humanos , Radiocirugia/métodos , Radiocirugia/tendencias , Terapia Asistida por Computador/métodos , Terapia Asistida por Computador/tendencias
15.
Strahlenther Onkol ; 174(7): 350-4, 1998 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-9689955

RESUMEN

PURPOSE: To fully utilize the technical capabilities of radiation diagnostics and planning, a precise and reproducible method of head fixation is a prerequisite. METHOD: We have adapted the Vogele-Bale-Hohner (VBH) head holder (Wellhöfer Dosimetrie, Schwarzenbruck, Germany), originally designed for frameless stereotactic operations, to the requirements of external beam radiotherapy. A precise and reproducible head fixation is attained by an individualized vacuum upper-dental cast which is connected over 2 hydraulic arms to an adjustable head- and rigid base-plate. Radiation field and patient alignment lasers are marked on a relocatable clear PVC localization box. RESULTS: The possibility of craniocaudal adjustment of the head plate on the base plate allows the system to adapt to the actual position of the patient on the radiotherapy couch granting tensionless repositioning. The VBH head holder has proven itself to be a precise yet practicable method of head fixation. Duration of mouthpiece production and daily repositioning is comparable to that of the thermoplastic mask. CONCLUSION: The new head holder is in routine use at our hospital and quite suitable for external beam radiation of patients with tumors of the head and neck.


Asunto(s)
Neoplasias de Cabeza y Cuello/radioterapia , Planificación de la Radioterapia Asistida por Computador/instrumentación , Restricción Física/instrumentación , Técnicas Estereotáxicas/instrumentación , Diseño de Equipo , Humanos , Protectores Bucales
16.
Int J Radiat Oncol Biol Phys ; 41(2): 475-83, 1998 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-9607367

RESUMEN

PURPOSE: To compare accuracy, clinical feasibility, and subjective patient impression between a noninvasive head holder (Vogele Bale Hohner [VBH]; Wellhoefer Dosimetry, Schwarzenbruck, Germany) developed at the University of Innsbruck and the thermoplastic mask fixation system for use in fractionated external radiotherapy. We present a case report of an actual patient fixated in the VBH head holder during radiation therapy. MATERIALS AND METHODS: The VBH head holder consists of an individualized vacuum dental cast connected to a head plate via two hydraulic arms allowing noninvasive, reproducible head fixation of even uncooperative patients. Accuracy was tested and compared with that of the thermoplastic mask using the Phillips EasyGuide navigation system on five volunteers. Specific external registration points served as landmarks and their positions were compared after each repositioning. System and operator inaccuracy were also taken into account. The times taken for production and repositioning of the respective fixation devices were compared, and subjective impressions were noted. RESULTS: Mean VBH head holder repositioning accuracy was 1.02 mm while that of the thermoplastic mask was 3.05 mm. 69% of mask repositionings showed a deviation > 2 mm and 41% > 3 mm (as opposed to 8% and 1% respectively for the VBH head holder) Those points located farthest away from the respective plane of fixation showed the largest deviations. Both production and repositioning times were similar between the systems; depending upon the patient, the VBH head holder was generally better tolerated than the mask system. CONCLUSION: Due to its significantly better repositioning accuracy compared to that of the thermoplastic mask, the VBH head holder is especially suited for external radiation requiring precise repositioning due to critical tissues in immediate surrounding of the area to be irradiated.


Asunto(s)
Carcinoma Adenoide Quístico/radioterapia , Materiales de Impresión Dental , Cabeza , Inmovilización , Neoplasias de los Senos Paranasales/radioterapia , Seno Esfenoidal , Adulto , Técnica de Impresión Dental , Fraccionamiento de la Dosis de Radiación , Diseño de Equipo , Humanos , Masculino , Protectores Bucales , Reproducibilidad de los Resultados
17.
J Eur Acad Dermatol Venereol ; 10(2): 137-42, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9553910

RESUMEN

BACKGROUND/AIMS: Topical glucocorticoids with improved benefit/risk ratio are of great interest in dermatology, but there are very few trials directly comparing the efficacy and side-effects of these new preparations. In our study the vasoconstrictor effect and side-effects of two of these new glucocorticoids were evaluated and blanching effect was determined by two-dimensional laser scanning. METHODS: In a randomised, double blind intra-individual comparative trial, 10 subjects were treated with various glucocorticoids or drug-free vehicle. The test drugs were mometasone furoate (MF), methylprednisolone aceponate (MP) and hydrocortisone (OH-C). The preparations were tested for a period of 3 weeks with occlusion on the flexor side of the forearm. Skin thickness and vasoconstriction were determined using 20 MHz ultrasound scanning, laser Doppler scanning (LDS) and chromometry. RESULTS: No adverse effects were observed during the observation period. Only partial vasoconstriction occurred in most cases during the observation period. MP and MF produced maximal blanching between days 3 and 5 of treatment, while with OH-C clinically visible blanching did not occur. Ultrasound evaluation of skin thickness showed similar behaviour for all three steroids tested: there were no signs of skin atrophy in any of the cases. LDS evidenced hypoperfusion of a test area on the perfusion image in only a few patients and there were no significant differences between the steroids tested. On evaluation of vasoconstriction caused by the steroids tested using chromometry there was a significant difference between MF and OH-C on the L*a*b* scale (P < 0.005). Only at day 3 was a blanching effect caused by MP and MF demonstrable (a-value, P < 0.05). CONCLUSION: In summary, the synthetic steroids MF and MP presented side-effects similar to those of OH-C but much greater vasoconstrictor effect; after an application period of over 5 days under occlusion a blanching effect in our model was not demonstrable by means of chromometry. Two-dimensional laser scanning offers no advantage in the evaluation of the blanching effect in comparison to one-dimensional laser fluxmetry (LDF).


Asunto(s)
Antiinflamatorios/efectos adversos , Hidrocortisona/efectos adversos , Metilprednisolona/efectos adversos , Pregnadienodioles/efectos adversos , Piel/efectos de los fármacos , Piel/patología , Vasoconstricción/efectos de los fármacos , Administración Tópica , Adolescente , Adulto , Antiinflamatorios/administración & dosificación , Atrofia/diagnóstico por imagen , Atrofia/patología , Femenino , Humanos , Hidrocortisona/administración & dosificación , Flujometría por Láser-Doppler , Masculino , Metilprednisolona/administración & dosificación , Persona de Mediana Edad , Furoato de Mometasona , Pregnadienodioles/administración & dosificación , Piel/diagnóstico por imagen , Espectrofotometría , Ultrasonografía
18.
Angiology ; 49(4): 307-14, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9555934

RESUMEN

Cyclosporin A (CyA) is intensively metabolized by the hepatic cytochrome p450 III monooxygenase A system in the human liver, the most important metabolites being M1, M17, and M21. Because CyA and its metabolites have nephrotoxic, hepatotoxic, and neurotoxic side effects, CyA dosage must be calculated to avoid the risk of organ rejection through underdosage and toxic organ damage through overdosage or accumulation of metabolites. In this study, we determined the whole-blood concentrations of cyclosporin and metabolite M17 by high-pressure liquid chromatography (HPLC) and by monoclonal specific and polyclonal nonspecific fluorescence polarization immunoassay (Abbott) in patients after immunosuppressive treatment. Patients with different resorption and metabolization rates showed high individual variations. CyA concentrations in patients with good liver function and low concentrations of CyA metabolites showed a good correlation between the HPLC and the FPIA (TDx-monoclonal assay) methods in ranges between 25 and 180 ng/mL. TDx-monoclonal was not always as precise as HPLC. In cases of metabolic disorders, we found false high CyA concentrations assayed with the immunologic method, caused by a crossreaction of the elevated metabolite concentration. We found that HPLC rendered more information about the extent of immunosuppressive activity and the metabolization rate and showed a good correlation with the concentration of metabolite M17 and total metabolites measured with the Abbott CyA polyclonal kit.


Asunto(s)
Ciclosporina/uso terapéutico , Ciclosporinas/sangre , Inmunosupresores/uso terapéutico , Anticuerpos , Anticuerpos Monoclonales , Enfermedades Autoinmunes/sangre , Enfermedades Autoinmunes/tratamiento farmacológico , Trasplante de Médula Ósea , Cromatografía Líquida de Alta Presión , Reacciones Cruzadas , Ciclosporina/administración & dosificación , Ciclosporina/efectos adversos , Ciclosporina/metabolismo , Ciclosporinas/efectos adversos , Sistema Enzimático del Citocromo P-450/metabolismo , Inmunoensayo de Polarización Fluorescente , Rechazo de Injerto/prevención & control , Trasplante de Corazón , Humanos , Terapia de Inmunosupresión , Inmunosupresores/administración & dosificación , Inmunosupresores/efectos adversos , Inmunosupresores/metabolismo , Riñón/efectos de los fármacos , Trasplante de Riñón , Hígado/efectos de los fármacos , Hígado/enzimología , Trasplante de Hígado , Tasa de Depuración Metabólica , Sistema Nervioso/efectos de los fármacos , Factores de Riesgo
19.
Strahlenther Onkol ; 174(2): 82-7, 1998 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-9487370

RESUMEN

AIM: The aim of this paper is to describe the adaption of 3D-navigation for interstitial brachytherapy. The new method leads to prospective and therefore improved planning of the therapy (position of the needle and dose distribution) and to the possibility of a virtual simulation (control if vessels or nerves are on the pathway of the needle). MATERIAL AND METHODS: The EasyGuide Neuro navigation system (Philips) was adapted in the way, that needles for interstitial brachytherapy were made connectable to the pointer and correctly displayed on the screen. To determine the positioning accuracy, several attempts were performed to hit defined targets on phantoms. Two methods were used: "free navigation", where the needle was under control of the navigation system, and the "guided navigation" where an aligned template was used additionally to lead the needle to the target. In addition a mask system was tested, whether it met the requirements of stable and reproducible positioning. The potential of applying this method in clinical practice was tested with an anatomical specimen. RESULTS: About 91% of all attempts lied within 5 mm. There were even better results on the more rigid table (94% < 4 mm). No difference could be seen between both application methods ("free navigation" and "navigation with template"), they showed the same accuracy. CONCLUSIONS: The accuracy of the phantom experiments and the confirmation by the experiment with the anatomical specimen showed that excellent results can be expected in clinical practice using rigid tables and patient supporting systems.


Asunto(s)
Braquiterapia/instrumentación , Fantasmas de Imagen , Braquiterapia/métodos , Diseño de Equipo , Humanos , Planificación de la Radioterapia Asistida por Computador , Reproducibilidad de los Resultados , Técnicas Estereotáxicas/instrumentación
20.
Ultraschall Med ; 19(6): 270-4, 1998 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-10028562

RESUMEN

PURPOSE: 20 MHz sonography of inflammatory diseases has concentrated on the evaluation of the echo-poor area in the upper dermis. With regard to higher resolution, this study focuses on the alterations of the epidermis and upper dermis skin using 100 MHz sonography. METHOD: 70 fully developed psoriasis vulgaris plaques of 20 patients were examined using our 100 MHz ultrasound equipment after application of salicylic acid in petrolatum for 24 h. After informing the patient about the aims of the study, a small knife biopsy was taken from 11 plaques. RESULTS: All psoriasis plaques exhibited, in comparison with normal skin, a significant widening of the skin entry echo (p < 0.001). Focally, this echo-rich line broke up into two thinner lines. Correlating histology exhibited in these areas an orthohyperkeratosis and focal parakeratosis. The upper dermis showed an echo-poor, band-shaped area which corresponded histologically to an acanthosis, elongation of rete ridges, and widening of the stratum papillare. The mean grey level of the echo-poor area and of the dermis beneath was significantly lower (p < 0.001) than the normal adjacent dermis. The thickness of the echo-poor area correlated with the thickness of the sum of the acanthosis and the inflammatory infiltrate in the histological sections (r = 0.94). CONCLUSION: Using 100 MHz sonography changes of the skin entry echo and the upper dermis can be visualized and quantified.


Asunto(s)
Psoriasis/diagnóstico por imagen , Adulto , Biopsia , Dermis/diagnóstico por imagen , Dermis/patología , Epidermis/diagnóstico por imagen , Epidermis/patología , Humanos , Masculino , Premedicación , Psoriasis/tratamiento farmacológico , Psoriasis/patología , Ácido Salicílico/administración & dosificación , Ultrasonografía
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