Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 205
Filtrar
Más filtros

Base de datos
Tipo del documento
Intervalo de año de publicación
1.
Radiat Oncol ; 16(1): 120, 2021 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-34183040

RESUMEN

BACKGROUND: In radiotherapy inaccuracy in organ at risk (OAR) delineation can impact treatment plan optimisation and treatment plan evaluation. Brouwer et al. showed significant interobserver variability (IOV) in OAR delineation in head and neck cancer (HNC) and published international consensus guidelines (ICG) for OAR delineation in 2015. The aim of our study was to evaluate IOV in the presence of these guidelines. METHODS: HNC radiation oncologists (RO) from each Belgian radiotherapy centre were invited to complete a survey and submit contours for 5 HNC cases. Reference contours (OARref) were obtained by a clinically validated artificial intelligence-tool trained using ICG. Dice similarity coefficients (DSC), mean surface distance (MSD) and 95% Hausdorff distances (HD95) were used for comparison. RESULTS: Fourteen of twenty-two RO (64%) completed the survey and submitted delineations. Thirteen (93%) confirmed the use of delineation guidelines, of which six (43%) used the ICG. The OARs whose delineations agreed best with the OARref were mandible [median DSC 0.9, range (0.8-0.9); median MSD 1.1 mm, range (0.8-8.3), median HD95 3.4 mm, range (1.5-38.7)], brainstem [median DSC 0.9 (0.6-0.9); median MSD 1.5 mm (1.1-4.0), median HD95 4.0 mm (2.3-15.0)], submandibular glands [median DSC 0.8 (0.5-0.9); median MSD 1.2 mm (0.9-2.5), median HD95 3.1 mm (1.8-12.2)] and parotids [median DSC 0.9 (0.6-0.9); median MSD 1.9 mm (1.2-4.2), median HD95 5.1 mm (3.1-19.2)]. Oral cavity, cochleas, PCMs, supraglottic larynx and glottic area showed more variation. RO who used the consensus guidelines showed significantly less IOV (p = 0.008). CONCLUSIONS: Although ICG for delineation of OARs in HNC exist, they are only implemented by about half of RO participating in this study, which partly explains the delineation variability. However, this study highlights that guidelines alone do not suffice to eliminate IOV and that more effort needs to be done to accomplish further treatment standardisation, for example with artificial intelligence.


Asunto(s)
Inteligencia Artificial , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/radioterapia , Variaciones Dependientes del Observador , Órganos en Riesgo/efectos de la radiación , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Humanos , Pronóstico , Dosificación Radioterapéutica
2.
Radiother Oncol ; 153: 180-188, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33065182

RESUMEN

BACKGROUND/PURPOSE: Delineation of the lymph node levels of the neck for irradiation of the elective clinical target volume in head and neck cancer (HNC) patients is time consuming and prone to interobserver variability (IOV), although international consensus guidelines exist. The aim of this study was to develop and validate a 3D convolutional neural network (CNN) for semi-automated delineation of all nodal neck levels, focussing on delineation accuracy, efficiency and consistency compared to manual delineation. MATERIAL/METHODS: The CNN was trained on a clinical dataset of 69 HNC patients. For validation, 17 lymph node levels were manually delineated in 16 new patients by two observers, independently, using international consensus guidelines. Automated delineations were generated by applying the CNN and were subsequently corrected by both observers separately as needed for clinical acceptance. Both delineations were performed two weeks apart and blinded to each other. IOV was quantified using Dice similarity coefficient (DSC), mean surface distance (MSD) and Hausdorff distance (HD). To assess automated delineation accuracy, agreement between automated and corrected delineations were evaluated using the same measures. To assess efficiency, the time taken for manual and corrected delineations were compared. In a second step, only the clinically relevant neck levels were selected and delineated, once again manually and by applying and correcting the network. RESULTS: When all lymph node levels were delineated, time taken for correcting automated delineations compared to manual delineations was significantly shorter for both observers (mean: 35 vs 52 min, p < 10-5). Based on DSC, automated delineation agreed best with corrected delineation for lymph node levels Ib, II-IVa, VIa, VIb, VIIa, VIIb (DSC >85%). Manual corrections necessary for clinical acceptance were 1.4 mm MSD on average and were especially low (<1mm) for levels II-IVa, VIa, VIIa and VIIb. IOV was significantly smaller with automated compared to manual delineations (MSD: 1.4 mm vs 2.5 mm, p < 10-11). When delineating only the clinically relevant neck levels, the correction time was also significantly shorter (mean: 8 vs 15 min, p < 10-5). Based on DSC, automated delineation agreed very well with corrected delineation (DSC > 87%). Manual corrections necessary for clinical acceptance were 1.3 mm MSD on average. IOV was significantly smaller with automated compared to manual delineations (MSD: 0.8 mm vs 2.3 mm, p < 10-3). CONCLUSION: The CNN developed for automated delineation of the elective lymph node levels in the neck in HNC was shown to be more efficient and consistent compared to manual delineation, which justifies its implementation in clinical practice.


Asunto(s)
Aprendizaje Profundo , Neoplasias de Cabeza y Cuello , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/radioterapia , Humanos , Estadificación de Neoplasias , Redes Neurales de la Computación , Variaciones Dependientes del Observador
3.
Eur Psychiatry ; 63(1): e47, 2020 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-32381136

RESUMEN

BACKGROUND: While polypharmacy is common in long-term residential psychiatric patients, prescription combinations may, from an evidence-based perspective, be irrational. Potentially, many psychiatric patients are treated on the basis of a poor diagnosis. We therefore evaluated the DITSMI model (i.e., Diagnose, Indicate, and Treat Severe Mental Illness), an intervention that involves diagnosis (or re-diagnosis) and appropriate treatment for severely mentally ill long-term residential psychiatric patients. Our main objective was to determine whether DITSMI affected changes over time regarding diagnoses, pharmacological treatment, psychosocial functioning, and bed utilization. METHODS: DITSMI was implemented in a consecutive patient sample of 94 long-term residential psychiatric patients during a longitudinal cohort study without a control group. The cohort was followed for three calendar years. Data were extracted from electronic medical charts. As well as diagnoses, medication use and current mental status, we assessed psychosocial functioning using the Health of the Nations Outcome Scale (HoNOS). Bed utilization was assessed according to length of stay (LOS). Change was analyzed by comparing proportions of these data and testing them with chi-square calculations. We compared the numbers of diagnoses and medication changes, the proportions of HoNOS scores below cut-off, and the proportions of LOS before and after provision of the protocol. RESULTS: Implementation of the DITSMI model was followed by different diagnoses in 49% of patients, different medication in 67%, some improvement in psychosocial functioning, and a 40% decrease in bed utilization. CONCLUSIONS: Our results suggest that DITSMI can be recommended as an appropriate care for all long-term residential psychiatric patients.


Asunto(s)
Benchmarking/estadística & datos numéricos , Tiempo de Internación/estadística & datos numéricos , Trastornos Mentales/tratamiento farmacológico , Adulto , Prescripciones de Medicamentos/estadística & datos numéricos , Femenino , Estudios de Seguimiento , Humanos , Cuidados a Largo Plazo/estadística & datos numéricos , Estudios Longitudinales , Masculino , Trastornos Mentales/psicología , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud
4.
Radiother Oncol ; 138: 68-74, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31146073

RESUMEN

PURPOSE/OBJECTIVE: Precise delineation of organs at risk (OARs) in head and neck cancer (HNC) is necessary for accurate radiotherapy. Although guidelines exist, significant interobserver variability (IOV) remains. The aim was to validate a 3D convolutional neural network (CNN) for semi-automated delineation of OARs with respect to delineation accuracy, efficiency and consistency compared to manual delineation. MATERIAL/METHODS: 16 OARs were manually delineated in 15 new HNC patients by two trained radiation oncologists (RO) independently, using international consensus guidelines. OARs were also automatically delineated by applying the CNN and corrected as needed by both ROs separately. Both delineations were performed two weeks apart and blinded to each other. IOV between both ROs was quantified using Dice similarity coefficient (DSC) and average symmetric surface distance (ASSD). To objectify network accuracy, differences between automated and corrected delineations were calculated using the same similarity measures. RESULTS: Average correction time of the automated delineation was 33% shorter than manual delineation (23 vs 34 minutes) (p < 10-6). IOV improved significantly with network initialisation for nearly all OARs (p < 0.05), resulting in decreased ASSD averaged over all OARs from 1.9 to 1.2 mm. The network achieved an accuracy of 90% and 84% DSC averaged over all OARs for RO1 and RO2 respectively, with an ASSD of 0.7 and 1.5 mm, which was in 93% and 73% of the cases lower than the IOV. CONCLUSION: The CNN developed for automated OAR delineation in HNC was shown to be more efficient and consistent compared to manual delineation, which justify its implementation in clinical practice.


Asunto(s)
Aprendizaje Profundo , Neoplasias de Cabeza y Cuello/radioterapia , Órganos en Riesgo , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Redes Neurales de la Computación , Variaciones Dependientes del Observador
6.
Oncoimmunology ; 7(4): e1419113, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29632737

RESUMEN

Vitiligo development in melanoma patients during immunotherapy is a favorable prognostic sign and indicates breakage of tolerance against melanocytic/melanoma antigens. We investigated a novel immunotherapeutic approach of the skin-depigmenting compound monobenzone synergizing with imiquimod in inducing antimelanoma immunity and melanoma regression. Stage III-IV melanoma patients with non-resectable cutaneous melanoma metastases were treated with monobenzone and imiquimod (MI) therapy applied locally to cutaneous metastases and adjacent skin during 12 weeks, or longer. Twenty-one of 25 enrolled patients were evaluable for clinical assessment at 12 weeks. MI therapy was well-tolerated. Partial regression of cutaneous metastases was observed in 8 patients and stable disease in 1 patient, reaching the statistical endpoint of treatment efficacy. Continued treatment induced clinical response in 11 patients, including complete responses in three patients. Seven patients developed vitiligo-like depigmentation on areas of skin that were not treated with MI therapy, indicating a systemic effect of MI therapy. Melanoma-specific antibody responses were induced in 7 of 17 patients tested and melanoma-specific CD8+T-cell responses in 11 of 15 patients tested. These systemic immune responses were significantly increased during therapy as compared to baseline in responding patients. This study shows that MI therapy induces local and systemic anti-melanoma immunity and local regression of cutaneous metastases in 38% of patients, or 52% during prolonged therapy. This study provides proof-of-concept of MI therapy, a low-cost, broadly applicable and well-tolerated treatment for cutaneous melanoma metastases, attractive for further clinical investigation.

7.
J Dermatolog Treat ; 28(1): 86-91, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27309418

RESUMEN

BACKGROUND: To date, autologous punch grafting appears to be the easiest and least expensive surgical technique for stable vitiligo and piebaldism. Punch grafting is available worldwide, with no need for specialised instruments. However, no reliable data on efficacy and safety of different punch depths and punch sizes are available. OBJECTIVE/METHODS: To compare the efficacy and safety of different punch depths and punch sizes in autologous punch grafting, a randomised controlled trial was performed in 33 patients with vitiligo or piebaldism. In each patient, four depigmented regions were allocated to: 1.5 mm deep grafts, 1.5 mm superficial grafts, 1.0 mm deep grafts, and 1.0 mm superficial grafts. Primary outcome was the total pigmented surface area. Secondary outcomes were Patients' Global Assessment (PGA) and side effects. RESULTS: Six months after grafting, 1.5 mm grafts showed a significantly larger pigmented surface area compared to 1.0-mm grafts (p < 0.001), though more side effects as well. No significant differences in the total pigmented surface between different punch depths were found. Deep grafts showed more erythema compared to superficial grafts. CONCLUSION: We recommend 1.5 mm superficial grafts in autologous punch grafting for trunk and proximal extremities in patients with stable vitiligo and piebaldism.


Asunto(s)
Piebaldismo/cirugía , Trasplante de Piel/métodos , Vitíligo/cirugía , Adolescente , Adulto , Extremidades , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Torso , Trasplante Autólogo/métodos , Resultado del Tratamiento , Adulto Joven
8.
Allergy ; 72(2): 282-290, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27392210

RESUMEN

RATIONALE: The European Position Paper on Sinusitis (EPOS) guidelines provide composite criteria to evaluate chronic rhinosinusitis (CRS) control, taking into consideration the severity of patients' symptoms, aspect of nasal mucosa and medical intake as parameters of CRS control. OBJECTIVES: To study the degree of CRS control using novel EPOS control criteria at 3-5 years after a functional endoscopic sinus surgery (FESS) and correlate these data to symptoms scores. METHODS: Adult CRS patients (n = 560) who had undergone bilateral FESS for chronic inflammatory sinonasal disease 3-5 years prior to the study were included. Patients received a postal questionnaire asking for control items according to EPOS control criteria, visual analogue scale (VAS) scores for total and individual sinonasal symptoms, sinonasal outcome test (SNOT)-22 and Short Form (SF)-36 questionnaires. MEASUREMENTS AND MAIN RESULTS: About 19.5% of CRS patients were well controlled, with 36.8% of patients being partly controlled and 43.7% uncontrolled. The levels of control corresponded to mean total VAS, SNOT-22 and SF-36 scores. Subgroup analysis revealed that female gender, aspirin intolerance and revision FESS were associated with higher prevalence of uncontrolled CRS, whereas allergy, asthma and smoking status did not alter the percentage of patients in each category of control. In 81 patients attending the outpatient clinic, nasal endoscopy changed classification in only four patients (4.9%). CONCLUSIONS: Based on the novel EPOS control criteria, at least 40% of CRS patients are uncontrolled at 3-5 years after FESS. Therefore, better treatment strategies leading to higher disease control are warranted in CRS care.


Asunto(s)
Laparoscopía/efectos adversos , Rinitis/epidemiología , Rinitis/etiología , Sinusitis/epidemiología , Sinusitis/etiología , Centros de Atención Terciaria , Adolescente , Adulto , Anciano , Bélgica/epidemiología , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Senos Paranasales/cirugía , Rinitis/prevención & control , Sinusitis/prevención & control , Encuestas y Cuestionarios , Adulto Joven
10.
Nat Genet ; 48(11): 1418-1424, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27723757

RESUMEN

Vitiligo is an autoimmune disease in which depigmented skin results from the destruction of melanocytes, with epidemiological association with other autoimmune diseases. In previous linkage and genome-wide association studies (GWAS1 and GWAS2), we identified 27 vitiligo susceptibility loci in patients of European ancestry. We carried out a third GWAS (GWAS3) in European-ancestry subjects, with augmented GWAS1 and GWAS2 controls, genome-wide imputation, and meta-analysis of all three GWAS, followed by an independent replication. The combined analyses, with 4,680 cases and 39,586 controls, identified 23 new significantly associated loci and 7 suggestive loci. Most encode immune and apoptotic regulators, with some also associated with other autoimmune diseases, as well as several melanocyte regulators. Bioinformatic analyses indicate a predominance of causal regulatory variation, some of which corresponds to expression quantitative trait loci (eQTLs) at these loci. Together, the identified genes provide a framework for the genetic architecture and pathobiology of vitiligo, highlight relationships with other autoimmune diseases and melanoma, and offer potential targets for treatment.


Asunto(s)
Enfermedades Autoinmunes/genética , Predisposición Genética a la Enfermedad , Vitíligo/genética , Femenino , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Masculino , Melanoma/genética , Sitios de Carácter Cuantitativo , Medición de Riesgo
14.
J Eur Acad Dermatol Venereol ; 29(11): 2145-51, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25868111

RESUMEN

BACKGROUND: Vitiligo is a common depigmenting skin disorder that can influence a patient's quality of life. Although patient-orientated medicine is an emerging concept, a self-assessment tool to assess the degree of depigmentation in vitiligo is not yet available. Therefore, we developed the SAVASI, a self-assessment tool that uses the same basic principles as the VASI. OBJECTIVE: To assess the validity, reliability and acceptability of the SAVASI. METHODS: To assess the validity of the SAVASI, we compared the scores assessed by the patient with the scores of the VASI assessed by the physician. To assess the intra-rater reliability, the correlation between the baseline SAVASI and the SAVASI after 2 weeks was calculated. To assess the acceptability, patients indicated the time needed to complete the SAVASI and the patient assessed the difficulty of the questionnaire on a five-point scale. The Skindex-29 was used to determine the quality of life. The overestimation of the SAVASI compared to the VASI was calculated by subtracting the VASI scores off from the SAVASI scores. RESULTS: A high correlation between the VASI and the SAVASI (ICC 0.97, 95% CI: 0.95-0.98) was found in 60 patients. The intra-rater reliability of the SAVASI (ICC 0.75, 95% CI 0.54-0.87) was adequate in 31 patients. Fifty (83%) of the patients completed the questionnaire within 10 min and only five (8%) of the patients considered the SAVASI hard. We found no correlation between overestimation of the SAVASI score and the Skindex-29 score. CONCLUSION: The SAVASI is a valid, reliable and acceptable self-assessment tool to measure the degree of depigmentation in vitiligo. With the SAVASI the degree of depigmentation can reliably be assessed by the patient themselves which can be useful in large (epidemiological) studies. Furthermore, this could contribute to the patient's disease insight and therapy loyalty.


Asunto(s)
Autoevaluación Diagnóstica , Calidad de Vida , Encuestas y Cuestionarios , Vitíligo/patología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Factores de Tiempo , Adulto Joven
15.
Br J Dermatol ; 172(2): 437-43, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25278165

RESUMEN

BACKGROUND: Vitiligo is a common skin disorder causing depigmented macules that can impair a patient's quality of life. Currently, there are no standardized outcome measures to assess the degree of depigmentation. Moreover, there is limited knowledge on the measurement properties of outcome measures in vitiligo. OBJECTIVES: To assess the reliability and responsiveness of the Vitiligo Area Scoring Index (VASI) and the Vitiligo European Task Force assessment (VETFa), two well-described clinician-reported outcomes. METHODS: We included three vitiligo patient groups. In one group of 31 patients, the interobserver reliability was assessed by three observers. In 27 patients the intraobserver reliability was assessed by two repeated measures by one of the observers. To assess the responsiveness the repigmentation was calculated after 6 months of phototherapy in 33 patients and tested against hypotheses. RESULTS: The interobserver reliability was high for VASI [intraclass correlation coefficient (ICC) 0·93] and VETFa depigmentation (ICC 0·88). The intraobserver reliability was high for VASI (ICC 0·93) and VETFa depigmentation (ICC 0·97). The smallest detectable changes (SDCs) were 7·1% and 10·4% for interobserver reliability and 4·7% and 2·9% for intraobserver reliability in VASI and VETFa depigmentation, respectively. All four responsiveness hypotheses formulated a priori were confirmed. CONCLUSIONS: VASI and VETFa are reliable and responsive instruments to assess the degree of depigmentation in vitiligo. VASI and VETFa for depigmentation are potential instruments for vitiligo research in the future. However, for use in individual patient care, caution is needed when interpreting score changes in individual patients because of the relatively large SDC.


Asunto(s)
Índice de Severidad de la Enfermedad , Vitíligo/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Sensibilidad y Especificidad , Adulto Joven
16.
J Synchrotron Radiat ; 21(Pt 5): 837-42, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25177975

RESUMEN

This article summarizes the contributions in this special issue on Diffraction-Limited Storage Rings. It analyses the progress in accelerator technology enabling a significant increase in brightness and coherent fraction of the X-ray light provided by storage rings. With MAX IV and Sirius there are two facilities under construction that already exploit these advantages. Several other projects are in the design stage and these will probably enhance the performance further. To translate the progress in light source quality into new science requires similar progress in aspects such as optics, beamline technology, detectors and data analysis. The quality of new science will be limited by the weakest component in this value chain. Breakthroughs can be expected in high-resolution imaging, microscopy and spectroscopy. These techniques are relevant for many fields of science; for example, for the fundamental understanding of the properties of correlated electron materials, the development and characterization of materials for data and energy storage, environmental applications and bio-medicine.


Asunto(s)
Diseño de Equipo/tendencias , Aumento de la Imagen/instrumentación , Óptica y Fotónica/tendencias , Sincrotrones/instrumentación , Difracción de Rayos X/instrumentación , Difracción de Rayos X/tendencias
17.
Pigment Cell Melanoma Res ; 27(6): 1086-96, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25043574

RESUMEN

Patients with melanoma may develop skin depigmentation spontaneously or following therapy, referred to as melanoma-associated leucoderma (MAL). As clinical presentation of MAL may precede primary/metastatic melanoma detection, recognition of MAL is important to prevent its misdiagnosis as vitiligo and the subsequent application of immunosuppressive treatment. To reveal the immunity involved in MAL development, we investigated the presence of antibody and T-cell immune responses directed against the melanocyte-differentiation-antigens MART-1 (Melan-A), tyrosinase and gp100 in patients with MAL, as compared to patients with vitiligo. Autoantibodies to gp100 and tyrosinase were commonly found in both diseases. Interestingly, MART-1 antibodies were only present in patients with MAL. Melanocyte antigen-specific T cells were found in all patients, with relatively more specific T cells in patients with active vitiligo. Although MAL and vitiligo may appear clinically similar, our results indicate that the humoral immune responses against MART-1 differ between these diseases, which can help to differentiate MAL from vitiligo.


Asunto(s)
Formación de Anticuerpos/inmunología , Hipopigmentación/complicaciones , Hipopigmentación/inmunología , Antígeno MART-1/inmunología , Melanoma/complicaciones , Melanoma/inmunología , Vitíligo/inmunología , Adolescente , Adulto , Anciano , Especificidad de Anticuerpos/inmunología , Linfocitos T CD8-positivos/inmunología , Demografía , Femenino , Humanos , Masculino , Melanocitos/inmunología , Melanocitos/patología , Melanoma/patología , Persona de Mediana Edad , Vitíligo/patología , Adulto Joven
18.
Opt Express ; 22(2): 1402-12, 2014 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-24515148

RESUMEN

Fresnel zone plates (FZPs) play an essential role in high spatial resolution x-ray imaging and analysis of materials in many fields. These diffractive lenses are commonly made by serial writing techniques such as electron beam or focused ion beam lithography. Here we show that pinhole diffraction holography has potential to generate FZP patterns that are free from aberrations and imperfections that may be present in alternative fabrication techniques. In this presented method, FZPs are fabricated by recording interference pattern of a spherical wave generated by diffraction through a pinhole, illuminated with coherent plane wave at extreme ultraviolet (EUV) wavelength. Fundamental and practical issues involved in formation and recording of the interference pattern are considered. It is found that resolution of the produced FZP is directly related to the diameter of the pinhole used and the pinhole size cannot be made arbitrarily small as the transmission of EUV or x-ray light through small pinholes diminishes due to poor refractive index contrast found between materials in these spectral ranges. We also find that the practical restrictions on exposure time due to the light intensity available from current sources directly imposes a limit on the number of zones that can be printed with this method. Therefore a trade-off between the resolution and the FZP diameter exists. Overall, we find that this method can be used to fabricate aberration free FZPs down to a resolution of about 10 nm.


Asunto(s)
Holografía/instrumentación , Rayos Láser , Nanoporos/ultraestructura , Refractometría/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo
19.
J Dermatolog Treat ; 25(2): 167-8, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23875611

RESUMEN

Folliculitis decalvans (FD) is a rare inflammatory scalp disorder presenting with tufted folliculitis, follicular papules and pustules, progressing to cicatricial alopecia. Current treatments mainly consist of antibiotic and immunomodulatory therapies and are often disappointing. FD has previously shown to respond to treatment with neodymium:yttrium aluminium garnet (Nd:YAG) laser in one case. We present a case of recalcitrant FD, successfully treated with a long-pulsed Nd:YAG laser.


Asunto(s)
Foliculitis/radioterapia , Láseres de Estado Sólido/uso terapéutico , Adulto , Humanos , Terapia por Láser , Masculino , Cuero Cabelludo
20.
Br J Dermatol ; 169(6): 1246-51, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23909405

RESUMEN

BACKGROUND: In widespread vitiligo, when repigmentation therapies are no longer feasible, Q-switched lasers can be used to remove the remaining disfiguring pigmentation. However, little literature is available on the long-term effects of Q-switched laser treatment in patients with vitiligo, and the variables influencing the effect of treatment are unknown. OBJECTIVE: To evaluate retrospectively the effectiveness, safety and patient satisfaction of Q-switched ruby (QSR) laser-induced depigmentation in widespread vitiligo. METHODS: We performed a retrospective study on well-documented patients with vitiligo with widespread lesions who received depigmentation therapy with the QSR laser between 2000 and 2012 in our institute. Eligible patients were asked to visit our institute for assessment of depigmentation and to fill in a questionnaire on patient satisfaction and disease variables. RESULTS: After a mean follow-up of 13 months, 48% of the 27 included patients showed > 75% depigmentation. Patients with active disease at the time of treatment had significantly better results than patients with stable disease (P < 0·05). Twenty-three (85%) patients were satisfied after treatment. Eighteen patients (67%) reported temporary side-effects after treatment. None of the patients reported adverse effects, such as scars or infections. CONCLUSION: Q-switched ruby laser therapy is effective in approximately half of patients treated; it is a safe treatment with a high patient satisfaction. Patients with active vitiligo show better results after treatment than patients with stable vitiligo. Therefore, in patients with stable vitiligo resistant to trial treatment, we advise postponing treatment until their vitiligo becomes active.


Asunto(s)
Láseres de Estado Sólido/uso terapéutico , Vitíligo/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Seguridad del Paciente , Satisfacción del Paciente , Estudios Retrospectivos , Encuestas y Cuestionarios , Resultado del Tratamiento , Vitíligo/psicología , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA