RESUMEN
AIM: The study aimed to evaluate the functional and anatomical results of patients treated with intravitreal ranibizumab (IVR) for neovascular age-related macular degeneration (n-AMD) but switched to intravitreal aflibercept (IVA) treatment due to insufficient response treatment. MATERIAL AND METHODS: At least six doses of n-AMD were administered IVR to 33 patients who were switched to IVA treatment due to insufficient response and were included in the study. The patients were evaluated at the beginning of the IVR treatment during the transition to IVA treatment and at 6, 12, 18, 24, 30, 36, and 42 months of IVA treatment. RESULTS: After an average of 10.1 ± 5.04 IVR injections, the patients who were accepted as insufficient response were treated with IVA. The central macular thickness of the patients was evaluated at the beginning of the treatment, immediately before, and after the initiation of IVA treatment at 6, 12, 18, 24, 30, 36, 42 months. It was as follows: 325.21 ± 123.04, 351.42 ± 126.09, 284.81 ± 112.65, 296.68 ± 89.17, 282.61 ± 81.58, 292.27 ± 109, 92,269.75 ± 97.14, 267.50 ± 87.56, and 266.82 ± 88.35 µm. According to the best-corrected visual acuity (BCVA), it was initially 0.89 ± 0.65; 1.08 ± 0.53 during the transition to IVA; 0.91 ± 0.46 6 months after IVA; 12th 1.14 ± 0.59; 0.94 ± 0.55 at 18th; 1.07 ± 0.49 at 24th; 1.15 ± 0.57 at 30th; 1.06 ± 0.45 at 36th, and 1.13 ± 0.46 LogMAR ( Logarithm of the Minimum Angle of Resolution) at the 42nd month. CONCLUSION: In conclusion, in n-AMD patients with inadequate response to intravitreal ranibizumab or with relapse, and therefore, switched to aflibercept treatment, the anatomical improvement and sustainment were observed, however, functional recovery could not be achieved.
Asunto(s)
Degeneración Macular , Ranibizumab , Inhibidores de la Angiogénesis , Estudios de Seguimiento , Humanos , Inyecciones Intravítreas , Degeneración Macular/tratamiento farmacológico , Ranibizumab/uso terapéutico , Receptores de Factores de Crecimiento Endotelial Vascular , Proteínas Recombinantes de Fusión , Estudios Retrospectivos , Resultado del Tratamiento , Agudeza VisualRESUMEN
To probe the influence of hydrogen bonding on the electronic structure of ammonia, gas phase and aqueous NH3 have been investigated using soft X-ray absorption (XAS), resonant inelastic soft X-ray scattering (RIXS), and electronic structure calculations including dynamical effects. Strong spectral differences in the XAS scans as well as in the RIXS spectra between gas phase and aqueous NH3 are attributed to orbital mixing with the water orbitals, dipole-dipole interactions, differences in vibronic coupling, and nuclear dynamics on the time-scale of the RIXS process. All of these effects are consequences of hydrogen bonding and the impact of the associated orbitals, demonstrating the power of XAS and RIXS as unique tools to study hydrogen bonding in liquids.
RESUMEN
BACKGROUND AND PURPOSE: Often, the most appropriate treatment for superficially and extensively spreading tumors of the skin is to use electron irradiation at enlarged distances. Rotational skin electron irradiation is a proven method for the treatment of the entire skin surface. We here report modifications of this technique in the set-up of partial-skin electron irradiation and the results of dosimetric examinations with regard to optimal shielding, dose profiles and depth dose curves under various irradiation conditions. MATERIALS AND METHODS: Irradiation was performed using electron beams with nominal energies of 6 MeV from a linear accelerator. The phantom was located on a rotating platform at a source-surface distance SSD=300 cm. A horizontal slit aperture (height: 32 cm) within a 2 cm thick polymethylmethacrylate (PMMA) shielding plate near the phantom was used to define the size of the irradiated region. Influences on dose distributions due to scattering processes on the PMMA edges were investigated using a flat ionization chamber and films. Absolute dose measurements and film calibration were made with the flat chamber. The quality of bremsstrahlung radiation behind the shielding was determined with a thimble ionization chamber in the phantom. RESULTS AND CONCLUSIONS: The results of rotational partial-skin electron irradiation reveal some of the investigated shielding geometries to be optimal. Depth dose distributions and dose rates correspond to the results obtained in total skin electron rotational irradiation. It is possible to apply the dose superficially in the first millimeters of the skin; the dose maximum is located at a depth of 0-2 mm, the 80% isodose at 9 mm. The amount of bremsstrahlung contamination is 2.5%. The local amount of absorbed dose per monitor unit depends strongly on patient/phantom cross-section geometry. At our institute, rotational partial-skin electron irradiation was implemented into clinical routine in 1997.
Asunto(s)
Dosificación Radioterapéutica , Neoplasias Cutáneas/radioterapia , Piel/efectos de la radiación , Absorciometría de Fotón , Calibración , Relación Dosis-Respuesta en la Radiación , Diseño de Equipo , Humanos , Fantasmas de Imagen , Polimetil Metacrilato , Protección Radiológica/instrumentación , Radioterapia de Alta Energía , Rotación , Dispersión de Radiación , Película para Rayos XRESUMEN
The therapeutic advantages of scanned electron beams from medical linear accelerators are accompanied by difficulties in electron dosimetry. Owing to short-time dose inhomogeneities in the treatment field, implicit in the system, time-consuming point-by-point measurements of dose distributions are normally required. However, by triggering the measuring time synchronously with the slow scan frequency, the time necessary to record reliable dose distributions can be shortened considerably. The instrumentation for the computer-controlled dosimetry system developed for this task is described. The results of our measurements show that reproducibility in dose within +/- 1% is achievable in less than 6.3 s per point for scanned electron beams.