Everolimus is ineffective for the treatment of progressive VS in NF2 patients. We are currently conducting a pharmacokinetic/pharmacodynamic ("phase 0") study of everolimus in presurgical VS patients to elucidate the biological basis for apparent treatment resistance to mTORC1 inhibition in these tumors.

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Rationale and Objectives: Quantifying changes in lung tumor volume is important for diagnosis, therapy planning, and evaluation of response to therapy. The aim of this study was to assess the performance of multiple algorithms on a reference data set. The study was organized by the Quantitative Imaging Biomarker Alliance (QIBA). Materials and Methods: The study was organized as a public challenge. Computed tomography scans of synthetic lung tumors in an anthropomorphic phantom were acquired by the Food and Drug Administration. Tumors varied in size, shape, and radiodensity. Participants applied their own semi-automated volume estimation algorithms that either did not allow or allowed post-segmentation correction (type 1 or 2, respectively). Statistical analysis of accuracy (percent bias) and precision (repeatability and reproducibility) was conducted across algorithms, as well as across nodule characteristics, slice thickness, and algorithm type. Results: Eighty-four percent of volume measurements of QIBA-compliant tumors were within 15% of the true volume, ranging from 66% to 93% across algorithms, compared to 61% of volume measurements for all tumors (ranging from 37% to 84%). Algorithm type did not affect bias substantially; however, it was an important factor in measurement precision. Algorithm precision was notably better as tumor size increased, worse for irregularly shaped tumors, and on the average better for type 1 algorithms. Over all nodules meeting the QIBA Profile, precision, as measured by the repeatability coefficient, was 9.0% compared to 18.4% overall. Conclusion: The results achieved in this study, using a heterogeneous set of measurement algorithms, support QIBA quantitative performance claims in terms of volume measurement repeatability for nodules meeting the QIBA Profile criteria.

INTRODUCCIÓN. La pandemia Covid-19 ha obligado a las instituciones educativas de todo el mundo a cambiar su modalidad de enseñanza, y pasar de un modelo mayormente presencial a otro donde la virtualidad presenta mayor protagonismo. OBJETIVO. Conocer la percepción de los docentes acerca de la educación a distancia durante la pandemia Covid-19 en una institución educativa estatal de Lima, Perú. MÉTODO. Estudio descriptivo transversal, con una muestra de 53 docentes en quienes se aplicó un cuestionario de 36 ítems, adaptación del Cuestionario de Educación a Distancia en tiempo de Covid-19 para docentes. RESULTADOS. Existe una experiencia media en formación a distancia (77,4%), falta de uso de plataformas educativas (67,9%) y uso masivo de WhatsApp como medio de comunicación (94,3%). El papel de las familias presentó menor calificación en comparación con el papel de la administración educativa y del centro escolar, resaltando el poco apoyo de los padres de familia y la falta de medios para desarrollar actividades virtuales. Asimismo, los docentes perciben una inadecuada formación en competencia digital. DISCUSIÓN Y CONCLUSIONES. Los docentes perciben muchas dificultades en la educación a distancia, especialmente por parte de los padres de familia y la poca formación adquirida.

Gadoxetic acid-enhanced magnetic resonance cholangiopancreatography (MRCP) was performed for evaluation of living donor liver transplantation. T2-weighted MRCP and hepatobiliary-phase postcontrast MRCP showed an aberrant right posterior bile duct, although the precise variant was uncertain. Optimized hepatobiliary-phase MRCP was obtained using 3 sequence modifications: increased flip angle to improve contrast between the biliary tree and surrounding tissues; radial k-space sampling to minimize motion artifact; and free-breathing acquisition to improve signal-to-noise ratio and, in turn, spatial resolution (resolution of 1.28 × 1.28 × 1.5 mm). The optimized sequence demonstrated that the right posterior bile duct drained into the cystic duct, consistent with type 3C biliary variant, thus modifying surgical planning.