PET-CT in presurgical lymph node staging in non-small cell lung cancer: the importance of false-negative and false-positive findings. / La PET-TC en la estadificación ganglionar prequirúrgica del carcinoma de pulmón de células no pequeñas: implicación de los falsos negativos y falsos positivos.

OBJECTIVE: To assess the importance of false-negative and false-positive findings in computed tomography (CT) and 18F-FDG positron emission tomography (PET) in mediastinal lymph node staging in patients undergoing surgery for non-small cell lung cancer (NSCLC). MATERIAL AND METHODS: This retrospective study included 113 consecutive patients and 120 resected NSCLCs; 22 patients received neoadjuvant treatment. We compared the findings on preoperative 18F-FDG PET-CT studies with the postoperative pathology findings. Lymph node size and primary tumor size were measured with CT, and lymph nodes and primary tumors were evaluated qualitatively and semiquantitatively (using standardized uptake values (SUVmax)) with PET. RESULTS: Metastatic lymph nodes were found in 26 (21.7%) of the 120 tumors and in 41 (7.7%) of the 528 lymph node stations analyzed. 18F-FDG PET-CT yielded 53.8% sensitivity, 76.6% specificity, 38.9% positive predictive value, 85.7% negative predictive value, and 71.7% diagnostic accuracy. The false-negative rate was 14.2%. Multivariable analysis found that the factors associated with false-negative findings were a moderate degree of differentiation in the primary tumor (p = 0.005) and an SUVmax of the primary tumor >4 (p = 0.027). The false-positive rate was 61.1%, and the multivariable analysis found that lymph node size >1cm was associated with false-positive findings (p < 0.001). CONCLUSIONS: In mediastinal lymph node staging in patients with NSCLC, 18F-FDG PET-CT improves the specificity and negative predictive value and helps clinicians to select the patients that will benefit from surgery. Given the high rate of false positives, histological confirmation of positive cases is recommendable.

[Update on the radiological study of pulmonary tuberculosis]. / Puesta al día en el estudio radiológico de la tuberculosis pulmonary.

Tuberculosis has made a comeback in recent years. This upsurge has been attributed to factors such as increased immigration and the human immunodeficiency virus epidemic. Primary pulmonary tuberculosis manifests radiologically with parenchymal involvement, lymph node involvement, pleural effusion, and/or miliary disease. In post-primary tuberculosis, the earliest radiological sign is small nodules and branching centrilobular lesions that increase in size and coalesce to form ill-defined patchy consolidations; cavitations are very characteristic of active disease. The aim of this article is to describe the radiologic findings for pulmonary tuberculosis and its complications.

Tumor pseudopapilar sólido de páncreas, una neoplasia inusual / Solid Pseudopapillary Tumor of the Pancreas, an Unusual Neoplasm

Presentación del caso. Se trata de una mujer de 26 años que presentó dolor en epigastrio e hipocondrio izquierdo, con aumento del perímetro abdominal y pérdida de 5 kg de peso corporal. En el examen físico se detectó una masa de gran tamaño en el epigastrio, con bordes regulares, ligeramente dolorosa al tacto y no móvil. Los estudios de imagen revelaron una neoplasia mixta en el cuerpo y cola pancreática. Intervención terapéutica. Se practicó una esplenopancreatectomía corpo-caudal, con extirpación completa del tumor. Evolución clínica. La paciente recibió cuidados especializados y vigilancia estrecha posquirúrgica en la unidad de cuidados intensivos, sin presentar complicaciones relevantes. Tras el alta hospitalaria, la paciente refirió un buen estado general en los controles de seguimiento, que incluyeron una tomografía realizada a los 12 meses, donde no se evidenciaron restos o recidivas tumorales

Case presentation. A 26-year-old woman who presented with pain in the epigastrium and left hypochondrium, with increased abdominal perimeter and loss of 5 kg of body weight. Physical examination revealed a large mass in the epigastrium, with regular borders, slightly painful to the touch and non-mobile. Imaging studies revealed a mixed neoplasm in the pancreatic body and tail. Treatment. A corpo-caudal splenopancreatectomy was performed, with complete removal of the tumor. Outcome. The patient received specialized care and close postoperative surveillance in the intensive care unit, with no relevant complications. After hospital discharge, the patient reported a good general condition in the follow-up controls, which included a computed tomography scan performed after 12 months, where no tumor remnants or recurrences were evidenced

Tomografía computarizada en el posoperatorio de cirugía abdominal mayor / Computed tomography scan after major abdominal surgery

RESUMEN Antecedentes: las cirugías abdominales mayores pueden presentar complicaciones posoperatorias graves cuya detección temprana resulta importante para su tratamiento. Objetivo: determinar la utilidad del uso de la tomografía computarizada (TC) para el diagnóstico temprano de las complicaciones de cirugía abdominal mayor. Materiales y métodos: estudio retrospectivo observacional descriptivo, mediante revisión de historias clínicas de pacientes operados de cirugía abdominal mayor en un Hospital Privado. Se agruparon los pacientes según presentaban o no síntomas sospechosos de complicación posoperatoria. Los primeros se clasificaron en 3 grupos: sin TC, con TC con hallazgos positivos y con TC sin hallazgos patológicos. Resultados: se analizaron 154 pacientes, con un promedio de edad de 61,3 ± 12,5 años; 83 (54%) fueron varones. Sobre 48 pacientes (31%) con síntomas sospechosos de complicaciones, fueron reoperados 6 sin TC, pero con síntomas muy evidentes, 7 con signos tomográficos positivos y 14/41 del grupo con TC negativa. Todos tuvieron hallazgos que justificaron la intervención. Hubo 27 casos (17,5%) con complicaciones IIIb según Clavien-Dindo y 3 pacientes (2%) fallecieron. Conclusión: la tomografía computarizada tuvo valor para confirmar una complicación, pero no para descartarla. Los parámetros clínicos cobran especial importancia en los pacientes sintomáticos sin hallazgos patológicos en la TC posoperatoria.

ABSTRACT Background: Major abdominal surgeries may present serious postoperative complications that require early diagnosis. Objective: The aim of this study was to determine the usefulness of computed tomography (CT) for the early diagnosis of major abdominal surgery complications. Material and methods: We conducted a retrospective, observational and descriptive study using data obtained from the medical records of patients undergoing major abdominal surgery in a private hospital. Patients were divided into two groups according to the presence or absence of symptoms suggesting a postoperative complication. Patients with symptoms were classified into 3 groups: without CT, with CT with positive findings and with CT without abnormal findings. Results: A total of 154 patients were analyzed; mean age was 61.3 ± 12.5 years and 83 (54%) were male. Of 48 patients (31%) with symptoms suggestive of complications, 6 had very evident symptoms and were re-operated without CT, 7 had positive findings on CT and CT was negative in 14/41. All the patients had findings that supported the decision to re-operate. There were 27 cases (17.5%) with grade 3b complications of the Clavien-Dindo classification and 3 patients (2%) died. Conclusion: Computed tomography was useful to confirm a complication, but not to rule it out. Clinical parameters remain of utmost importance in patients with symptoms and absence of abnormal findings in post-operative CT.

Relaciones del origen del tronco celiaco, arterias mesentéricas y renales con la columna vertebral en individuos chilenos / Relationships between of the origin of celiac trunk, mesenteric and renal arteries with the vertebral column in chilean individuals

En la actualidad muchos procedimientos quirúrgicos invasivos, diagnósticos y terapéuticos requieren de un conocimiento preciso de la anatomía arterial del territorio abdominal. Entre estas intervenciones destaca la extracción de órganos en donantes vivos (renal y hepático) y las intervenciones oncológicas, entre otras. Tradicionalmente, el estudio de los vasos se ha hecho por medio de arteriografías que requieren de procedimientos invasivos con inyección de medio de contraste y largas exposiciones a rayos X, obteniendo imágenes bidimensionales en las cuales las relaciones entre los tejidos y órganos es difícil de analizar. El objetivo del presente trabajo fue determinar las características anatómicas del tronco celiaco, arterias mesentérica superior, renales y mesentérica inferior y la relación de origen con la columna vertebral. Se estudiaron las imágenes de 74 pacientes, 40 hombres y 34 mujeres, sometidos a una angiotomografía de la parte abdominal de la aorta, registrando las características y las relaciones de las arterias mencionadas. Las imágenes utilizadas se obtuvieron mediante tomografía computarizada helicoidal multidetectores. La división clásica del tronco celíaco en tres ramas se encontró en el 60,8 por ciento de los casos, el origen se relacionó con T12 en 50 por ciento de los hombres y en 52,9 por ciento de las mujeres, con L1 en 50 por ciento y 47,1 por ciento, respectivamente. La a. mesentérica superior se originó a nivel de T12, L1 y L2 en un 8,1 por ciento, 78,4 por ciento y 13,5 por ciento, respectivamente. Las aa. renales fueron dobles en el 18,9 por ciento de los casos. Con respecto a las descripciones clásicas encontramos diferencias que demuestran la variabilidad de la distribución vascular. El método se valida como una instancia útil de bajo riesgo para el paciente y reproducible por los investigadores y clínicos.

At present many surgical invasive, diagnostic and therapeutic procedures require a precise knowledge of the arterial anatomy of the abdominal territory. Among these interventions the extraction of organs stands out in alive donors (renal and hepatic) and the oncological interventions, among others. Traditionally, the study of the vascularization has been carried out by means of arteriographies which require invasive procedures with injection of contrast substances and long expossue to X-rays, obtaining two-dimensional images in which the relations between the tissues and organs is difficult to analyze. The aim of the present work was to determine the anatomical characteristics of the celiac trunk, superior mesenteric, renal and inferior mesenteric arteries and the relation of origin with the vertebral column. Images of 74 patients, 40 men and 34 women, submitted to an tomography of the abdominal part of the aorta, were studied as were the characteristics and the relations of the mentioned arteries. Images used were obtained by means of multidetector computed tomography. The classic division of the celiac trunk in three branches was observed in 60,8 percent of the cases, the origin related with T12 in 50 percent of the men and in 52,9 percent of the women, with L1 in 50 percent and 47,1 percent, respectively. The superior mesenteric artery originated to level of T12, L1 and L2 in 8,1 percent, 78,4 percent and 13,5 percent, respectively. The renal arteries were double in 18,9 percent of the cases. With regard to the classic descriptions we found differences that demonstrate the variability of the vascular distribution. The method is validated as a useful instance of low risk for the patient and reproducible for the researchers and clinical.