Diagnostic Efficacy of 18F-FDG PET/CT in Detecting Bone Marrow Infiltration in Patients with Newly Diagnosed Diffuse Large B-Cell Lymphoma / 生物医学与环境科学（英文）

OBJECTIVE@#Diffuse large B-cell lymphoma (DLBCL) is often associated with bone marrow infiltration, and 2-deoxy-2-(18F) fluorodeoxyglucose positron emission tomography/computed tomography ( 18F-FDG PET/CT) has potential diagnostic significance for bone marrow infiltration in DLBCL.@*METHODS@#A total of 102 patients diagnosed with DLBCL between September 2019 and August 2022 were included. Bone marrow biopsy and 18F-FDG PET/CT examinations were performed at the time of initial diagnosis. Kappa tests were used to evaluate the agreement of 18F-FDG PET/CT with the gold standard, and the imaging features of DLBCL bone marrow infiltration on PET/CT were described.@*RESULTS@#The total detection rate of bone marrow infiltration was not significantly different between PET/CT and primary bone marrow biopsy ( P = 0.302) or between the two bone marrow biopsies ( P = 0.826). The sensitivity, specificity, and Youden index of PET/CT for the diagnosis of DLBCL bone marrow infiltration were 0.923 (95% CI, 0.759-0.979), 0.934 (95% CI, 0.855-0.972), and 0.857, respectively.@*CONCLUSION@#18F-FDG PET/CT has a comparable efficiency in the diagnosis of DLBCL bone marrow infiltration. PET/CT-guided bone marrow biopsy can reduce the misdiagnosis of DLBCL bone marrow infiltration.

Aportes de la tomografía por emisión de positrones con 18F-fluorodesoxiglucosa/tomografía computada en el diagnóstico de compromiso extramedular por mieloma múltiple en Uruguay / 18F-fluorodesoxyglucose positron emission tomography/computed tomography in extramedullary multiple myeloma

BACKGROUND: 18F-fluorodesoxyglucose positron emission tomography/ computed tomography (PET-CT) has a high sensitivity and specificity to detect medullary and extramedullary lesions in multiple myeloma (MM). AIM: To describe the findings of PET-CT in extramedullary multiple myeloma (EMM) at diagnosis and at relapse, and correlate its results with clinical variables, response to treatment and survival. MATERIALS AND METHODS: Review of medical records and PET-CT reports of 39 patients with multiple myeloma (MM) who had at least one PET-CT study, treated between January 1, 2015, and January 1, 2019 at a clinical hospital. RESULTS: The Standard Uptake Values for each hypermetabolic lesion were not described in PET-CT reports. Fifteen patients had an EMM and in eight, without a previous clinical suspicion, PET-TC lead to the diagnosis. The mortality rate in the 39 patients with MM was 46%. Sixty seven percent of deaths occurred in patients with EMM. CONCLUSIONS: PET-TC was useful to diagnose EMM. However, a standardization in PETCT reports would be required to unify criteria. As previously reported, EMM had a greater aggressiveness and lower survival.

Viabilidade miocárdica na prática clínica / Assessing myocardial viability in clinical practice

Embora a avaliação da viabilidade miocárdica seja comum na prática do cardiologista, muitos médicos têm dúvidas a respeito dos resultados dos métodos diagnósticos. A medicina nuclear tem papel importante nos estudos de viabilidade, mas os laudos precisam ser interpretados num contexto clínico e fisiopatológico. Este artigo teve o objetivo de revisar a origem e a evolução do conceito da viabilidade miocárdica. São expostos os métodos diagnósticos com ênfase na medicina nuclear com uma explicação funcional sobre cada tipo de exame. A partir disso, são mostradas imagens como exemplos e é proposta uma maneira de atuar nesses casos baseada na clínica, na porcentagem de miocárdio acometido e na topografia das lesões coronarianas (proximais ou distais). (AU)

Although assessing myocardial viability is a common cardiology practice, many physicians question the results of diagnostic methods. Nuclear medicine plays an important role in viability studies, but the reports require interpretation in a clinical and pathophysiological context. this article was aimed at reviewing the origin and evolution of myocardial viability. Here we present diagnostic methods by emphasizing nuclear medicine and provide a functional explanation of each test type using example images. We also propose how to act in these cases based on clinic examination findings, the percentage of affected myocardium, and coronary lesion topography (proximal or distal).(AU)

Progressive massive fibrosis in pneumoconiosis is mimicking lung malignancy on (18)F-FDGPET-CT: two cases report / 中华劳动卫生职业病杂志

Occupational pneumoconiosis is one of the main occupational diseases in China. Progressive massive fibrosis in pneumoconiosis should be distinguished from lung cancer for their similar imaging features which is often identified by (18)F-FDG PET-CT in clinic. Here we reported two cases of pneumoconiosis. Both of them were suspected of carrying malignant tumors by preoperative PET-CT exam, however, nodules in these two patients were all proved to be benign by intraoperative pathology which suggested that there is false-positive possibility in the distinguishment of pneumoconiosis nodules by (18)F-FDG PET-CT.

The correlation between metabolic parameters in (18)F-FDG PET-CT and solid and micropapillary histological subtypes in lung adenocarcinoma / 中华肿瘤杂志

Objective: Solid and micropapillary pattern are highly invasive histologic subtypes in lung adenocarcinoma and are associated with poor prognosis while the biopsy sample is not enough for the accurate histological diagnosis. This study aims to assess the correlation and predictive efficacy between metabolic parameters in (18)F-fluorodeoxy glucose positron emission tomography/computed tomography ((18)F-FDG PET-CT), including the maximum SUV (SUV(max)), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and solid and micropapillary histological subtypes in lung adenocarcinoma. Methods: A total of 145 resected lung adenocarcinomas were included. The clinical data and preoperative (18)F-FDG PET-CT data were retrospectively analyzed. Mann-Whitney U test was used for the comparison of the metabolic parameters between solid and micropapillary subtype group and other subtypes group. Receiver operating characteristic (ROC) curve and areas under curve (AUC) were used for evaluating the prediction efficacy of metabolic parameters for solid or micropapillary patterns. Univariate and multivariate analyses were conducted to determine the prediction factors of the presence of solid or micropapillary subtypes. Results: Median SUV(max) and TLG in solid and papillary predominant subtypes group (15.07 and 34.98, respectively) were significantly higher than those in other subtypes predominant group (6.03 and 10.16, respectively, P<0.05). ROC curve revealed that SUV(max) and TLG had good efficacy for prediction of solid and micropapillary predominant subtypes [AUC=0.811(95% CI: 0.715~0.907) and 0.725(95% CI: 0.610~0.840), P<0.05]. Median SUV(max) and TLG in lung adenocarcinoma with the solid or micropapillary patterns (11.58 and 22.81, respectively) were significantly higher than those in tumors without solid and micropapillary patterns (4.27 and 6.33, respectively, P<0.05). ROC curve revealed that SUV(max) and TLG had good efficacy for predicting the presence of solid or micropapillary patterns [AUC=0.757(95% CI: 0.679~0.834) and 0.681(95% CI: 0.595~0.768), P<0.005]. Multivariate logistic analysis showed that the clinical stage (Stage Ⅲ-Ⅳ), SUV(max) ≥10.27 and TLG≥7.12 were the independent predictive factors of the presence of solid or micropapillary patterns (P<0.05). Conclusions: Preoperative SUV(max) and TLG of lung adenocarcinoma have good prediction efficacy for the presence of solid or micropapillary patterns, especially for the solid and micropapillary predominant subtypes and are independent factors of the presence of solid or micropapillary patterns.

Chronic hypoperfusion due to intracranial large artery stenosis is not associated with cerebral β-amyloid deposition and brain atrophy / 中华医学杂志(英文版)

BACKGROUND@#Insufficient cerebral perfusion is suggested to play a role in the development of Alzheimer disease (AD). However, there is a lack of direct evidence indicating whether hypoperfusion causes or aggravates AD pathology. We investigated the effect of chronic cerebral hypoperfusion on AD-related pathology in humans.@*METHODS@#We enrolled a group of cognitively normal patients (median age: 64 years) with unilateral chronic cerebral hypoperfusion. Regions of interest with the most pronounced hypoperfusion changes were chosen in the hypoperfused region and were then mirrored in the contralateral hemisphere to create a control region with normal perfusion. 11C-Pittsburgh compound-positron emission tomography standard uptake ratios and brain atrophy indices were calculated from the computed tomography images of each patient.@*RESULTS@#The median age of the 10 participants, consisting of 4 males and 6 females, was 64 years (47-76 years). We found that there were no differences in standard uptake ratios of the cortex (volume of interest [VOI]: P = 0.721, region of interest [ROI]: P = 0.241) and grey/white ratio (VOI: P = 0.333, ROI: P = 0.445) and brain atrophy indices (Bicaudate, Bifrontal, Evans, Cella, Cella media, and Ventricular index, P > 0.05) between the hypoperfused regions and contralateral normally perfused regions in patients with unilateral chronic cerebral hypoperfusion.@*CONCLUSION@#Our findings suggest that chronic hypoperfusion due to large vessel stenosis may not directly induce cerebral β-amyloid deposition and neurodegeneration in humans.

Proceso para la fusión de neuroimágenes de Tomografía por Emisión de Positrones y Resonancia Magnética / Process for the fusion of Positron Emission Tomography and Magnetic Resonance neuroimaging

En radiología se utilizan varias técnicas imagenológicas para el diagnóstico de enfermedades y la asistencia en intervenciones quirúrgicas con el objetivo de determinar la ubicación y dimensión exacta de un tumor cerebral. Técnicas como la Tomografía por Emisión de Positrones y la Resonancia Magnética permiten determinar la naturaleza maligna o benigna de un tumor cerebral y estudiar las estructuras del cerebro con neuroimágenes de alta resolución. Investigadores a nivel internacional han utilizado diferentes técnicas para la fusión de la Tomografía por Emisión de Positrones y Resonancia Magnética al permitir la observación de las características fisiológicas en correlación con las estructuras anatómicas. La presente investigación tiene como objetivo elaborar un proceso para la fusión de neuroimágenes de Tomografía por Emisión de Positrones y Resonancia Magnética. Para ello se definieron 5 actividades en el proceso y los algoritmos a utilizar en cada una, lo cual propició identificar los más eficientes para aumentar la calidad en el proceso de fusión. Como resultado se obtuvo un proceso de fusión de neuroimágenes basado en un esquema híbrido Wavelet y Curvelet que garantiza obtener imágenes fusionadas de alta calidad(AU)

In radiology, various imaging techniques are used for the diagnosis of diseases and assistance in surgical interventions with the aim of determining the exact location and dimension of a brain tumor. Techniques such as Positron Emission Tomography and Magnetic Resonance can determine the malignant or benign nature of a brain tumor and study brain structures with high-resolution neuroimaging. International researchers have used different techniques for the fusion of Positron Emission Tomography and Magnetic Resonance, allowing the observation of physiological characteristics in correlation with anatomical structures. The present research aims to develop a process for the fusion of neuroimaging of Positron Emission Tomography and Magnetic Resonance Imaging. Five activities were defined in the process and the algorithms to be used in each one, which led identifying the most efficient ones to increase the quality in the fusion process. As a result, a neuroimaging fusion process was obtained based on a hybrid Wavelet and Curvelet scheme that guarantees high quality merged images(AU)

Relación de las cinéticas del PSA en la detección de la recurrencia del cáncer de próstata post prostatectomía radical con la 18f-colina tomografía por emisión de positrones/tomografía computada [PET/TC colina (PETC)] / Kinetic Relation Between PSA and 18F-choline PET/ CT in the Detection of Recurrent Prostatic Cancer After Radical Prostatectomy

Resumen Objetivo: El objetivo de este estudio es evaluar la relación de las cinéticas del antígeno prostático específico (PSA por su sigla en inglés) con la positividad de la tomografía por emisión de positrones/tomografía computada [PET/TC colina (PETC)]en pacientes con una recaída de cáncer de próstata (RCP). Materiales y métodos: Se realizó un trabajo retrospectivo de 48 pacientes con RCP post prostatectomía radical (PR) evaluados con PETC. Resultados: La PETC negativa tuvo una mediana de 16,3 meses y la PETC positiva de 5,5 meses (p = < 0,001) para el tiempo de doblaje de PSA (PSADT por su sigla en inglés); la PETC fue positiva en el 96% de los pacientes con un PSADT< 12 meses. La PETC negativa tuvo una mediana de 0,03 ng/ml/año y la PETC positiva de 4,1 ng/ml/año (p = < 0,001) para la velocidad del PSA (PSAVpor su sigla en inglés); la PETC fue positiva en el 92% de los pacientes con un PSAV > 0,75 ng/ml/año. Las áreas bajo la curva ROC para PSAV fue de 0,984 con un punto de corte de mayor discriminación de 0.785 ng/ml/año, mostrando razones de verosimilitud (LR por su sigla en inglés) LR + = 25 y LR- = 0,1. Para PSADT el ROC fue de 0,992 con un punto de corte de mayor discriminación de 11 meses, mostrando LR + = 11 y LR- = 0. Discusión: El PSA es un indicador inespecífico de PETC positiva. Un estudio inicial demostró que los pacientes con una RCP con una PETC positiva tenían un menor PSADT y una mayor PSAV que los pacientes con una PETC negativa. Conclusión: La positividad de la PETC se vio influenciada por las cinéticas del PSA, observándose que a menor PSADT y que a mayor PSAV mayor fue la probabilidad de la positividad de la PETC.

Abstract Purpose: The aim of this study is to evaluate the relationship between Prostate-Specific Antigen (PSA) kinetics and the detection of Prostate Cancer Relapse (PCR) with Positron-Emission Tomography (PETC). Material and methods: A retrospective study of 48 patients with a PCR after a radical prostatectomy evaluated with PETC was performed. Results: PSA Doubling Time (PSADT), with negative PETC, had a median of 16.3 months and the positive PETC a median of 5.5 months (p = < 0.001); 96% of patients with a PSADT <12 months had positive PETC. PSA Velocity (PSAV), negative PETC, had a median of 0.03 ng/ml/year and positive PETC a median of 4.1 ng/ml/year (p = < 0.001); 92% of patients who had a PSAV > 0.75 ng/ml/year had positive PETC. The ROC for PSAV was 0.984 with a cut-off value of 0.785 ng/ml/year, Showing Likelihood Ratios (LR) LR + = 25 and LR- = 0.1. The ROC for PSADT was 0.992 with a cut off value of 11 months, showing LR + = 11 and LR- = 0. Discussion: PSA is a nonspecific indicator of positive PETC. An initial study demon-strated that patients with a PCR and positive PETC had lower PSADT and higher PSAV than patients with a negative PETC. Conclusion: The rate of detection of PCR with PETC was influenced by the kinetics of PSA, and it was observed that the lower the PSADT and the higher the PSAV, the greater the probability of the positivity of the PETC.

Análisis y selección de técnicas para la fusión de imágenes PET/CT basado en software / Analysis and selection of techniques for the fusion of PET/CT imaging based on software

Técnicas como la Tomografía por Emisión de Positrones y la Tomografía Computarizada permiten determinar la naturaleza maligna o benigna de un tumor y estudiar las estructuras anatómicas del cuerpo con imágenes de alta resolución, respectivamente. Investigadores a nivel internacional han utilizado diferentes técnicas para la fusión de la Tomografía por Emisión de Positrones y la Tomografía Computarizada porque permite observar las funciones metabólicas en correlación con las estructuras anatómicas. La presente investigación se propone realizar un análisis y selección de algoritmos que propicien la fusión de neuroimágenes, basado en la precisión de los mismos. De esta forma contribuir al desarrollo de software para la fusión sin necesidad de adquirir los costosos equipos de adquisición de imágenes de alto rendimiento, los cuales son costosos. Para el estudio se aplicaron los métodos Análisis documental, Histórico lógico e Inductivo deductivo. Se analizaron e identificaron las mejores variantes de algoritmos y técnicas para la fusión según la literatura reportada. A partir del análisis de estas técnicas se identifica como mejor variante el esquema de fusión basado en Wavelet para la fusión de las imágenes. Para el corregistro se propone la interpolación Bicúbica. Como transformada discreta de Wavelet se evidencia el uso de la de Haar. Además, la investigación propició desarrollar el esquema de fusión basado en las técnicas anteriores. A partir del análisis realizado se constataron las aplicaciones y utilidad de las técnicas de fusión como sustitución a los altos costos de adquisición de escáneres multifunción PET/CT para Cuba(AU)

Techniques such as Positron Emission Tomography and Computed Tomography allow to determine the malignant or benign nature of a tumor and to study the anatomical structures of the body with high resolution images, respectively. International researchers have used different techniques for the fusion of Positron Emission Tomography and Computed Tomography because it allows observing metabolic functions in correlation with anatomical structures. The present investigation proposes to carry out an analysis and selection of algorithms that favor the fusion of neuroimaging, based on their precision. In this way, contribute to the development of fusion software without the need to purchase expensive high-performance imaging equipment, which is expensive. For the study the documentary analysis, logical historical and deductive inductive methods were applied. The best algorithm variants and techniques for fusion were analyzed and identified according to the reported literature. From the analysis of these techniques, the Wavelet-based fusion scheme for image fusion is identified as the best variant. Bicubic interpolation is proposed for co-registration. As a discrete Wavelet transform, the use of Haar's is evidenced. In addition, the research led to the development of the fusion scheme based on the previous techniques. From the analysis carried out, the applications and usefulness of fusion techniques were verified as a substitute for the high costs of acquiring PET / CT multifunction scanners for Cuba(AU)

Schwannoma mediastínico gigante / Giant mediastinal schwannoma

El schwannoma es un tumor neurogénico que se presenta más frecuentemente en el ángulo costovertebral del mediastino posterior, pero también en otras localizaciones dentro del tórax. Habitualmente suele ser una masa única, encapsulada, bien definida, con un tamaño aproximado 2 a 10 cm. Presentamos el caso de un paciente de 66 años, derivado a nuestro hospital por una masa de 13 cm localizada en el hemitórax inferior izquierdo. Se realizó una biopsia, y la resonancia magnética corroboró el diagnóstico de un tumor mediastínico gigante de la vaina neural. Se procedió a su resección completa sin complicaciones.

Schwannomas are neurogenic tumors, commonly located in the costovertebral angle of the posterior mediastinum, but with many intrathoracic locations. They usually present as a solitary, well-circumscribed and encapsulated mass with a size between 2 and 10 cm. We report a case of a 66-year-old male, referred to our hospital for a mass located at the left lower hemithorax with 13 cm in size. A percutaneous biopsy was performed, and magnetic resonance imaging confirmed the diagnosis of a resectable giant mediastinal nerve sheath tumor. Surgery was performed without complications.

Ascitis quilosa en el posoperatorio de hepatectomía derecha / Chylous ascites after right liver resection

La ascitis quilosa posoperatoria (AQP) se debe a acumulación de líquido rico en triglicéridos en la cavidad peritoneal tras una lesión en la cisterna del quilo o en sus afluentes. Es infrecuente verla después de una hepatectomía. Se presenta el caso de un varón de 44 años con adenocarcinoma a 16 cm del margen anal T3N1, con metástasis que ocupaba casi la totalidad del lóbulo hepático derecho. Luego de quimioterapia se realizó hepatectomía derecha, observándose al cuarto día postoperatorio líquido del drenaje endotorácico de aspecto lechoso, con triglicéridos 223 mg/dL y 77 mg/dL de triglicéridos séricos. Se inició dieta sin grasas, hiperproteica, con ácidos grasos de cadena media y octreótide (100 microgramos subcutáneos cada 8 horas), con resolución del cuadro. En conclusión, la complicación quilosa puede tratarse exitosamente con un abordaje menos agresivo, sin suprimir la ingesta oral, utilizando octreótide subcutáneo, dieta exenta de grasas, suplementada con proteínas y ácidos grasos de cadena media.

Postoperative chylous ascites is an intraperitoneal collection of lymphatic fluid enriched with long-chain triglycerides that results from injury of the cisterna chyli or its main tributaries. This complication is rare after liver resections. Here, we report on the case of a 44 year-old man with a T3N1 rectal adenocarcinoma 16 cm above the anal margin, with metastatic compromise of almost the entire right liver lobe. Following chemotherapy, he underwent right liver resection. On postoperative day four, the thoracic drain evidenced milky fluid containing triglyceride 223 mg/dL with serum triglycerides 77 mg/dL. A fat-free diet was indicated with fat-free protein supplements, medium chain triglycerides and octreotide (100 μg subcutaneously every 8 hours), with complete resolution. In conclusion, postoperative chylous complications may be treated successfully by a less aggressive approach, with oral diet, subcutaneous octreotide, fat-free diet supplemented with proteins and medium chain fatty acids.

Tomografía por emisión de positrones en el diagnóstico de sarcoidosis y síndrome de Löfgren / Tomography by emission of positrons in the diagnosis of sarcoidosis and Löfgren's syndrome

La sarcoidosis es una enfermedad granulomatosa no caseificante, multisistémica, de causa desconocida, que compromete el pulmón y los ganglios linfáticos mediastinales entre el 90-95 por ciento de los casos. También puede afectar otros órganos como las glándulas salivales, piel, ojos, hígado, bazo, corazón, huesos y sistema nervioso central. El compromiso torácico representa la principal causa de morbilidad con unas 10/100 000 personas al año y mortalidad. Nuestro estudio tuvo como objetivo presentar a un paciente de 45 años de edad atendido por tener manifestaciones clínicas, paraclínicas y radiográficas que permitieron establecer, sin confirmar mediante estudio histológico, el diagnóstico de una forma aguda de sarcoidosis. Su forma clínica de expresión coincidió con el síndrome de Löfgren con ensanchamiento mediastinal bilateral por linfoadenopatía hiliar, síndrome febril, eritema nudoso y artritis aguda en miembros inferiores, que desarrollan entre un 20-30 por ciento de los pacientes con sarcoidosis. Se le realizó una tomografía por emisión de positrones, cuyos resultados ofrecieron elementos diagnósticos propios de un proceso inflamatorio pulmonar alejado de las características propias de una neoplasia maligna. Después de una profunda evaluación del riesgo-beneficio, se impuso tratamiento inmunosupresor con esteroides a dosis elevadas y seguimiento estrecho. Observamos una evolución muy positiva e inmediata desde el punto de vista clínico y radiográfico. Luego de varias semanas de tratamiento se apreciaron los cambios con marcada mejoría hasta pasados 3 meses que constatamos prácticamente una casi desaparición de las imágenes radiográficas(AU)

Sarcoidosis is a multisystemic, non-caseating granulomatous disease of unknown cause that involves the lung and the mediastinal lymph nodes in between 90 percent and 95 percent of cases. It can also affect other organs, such as the salivary glands, skin, eyes, liver, spleen, heart, bones, and central nervous system. Thoracic involvement represents the main cause of morbidity and mortality in patients with this entity, which occurs in about 10 / 100,000 people a year. Our study aimed to present a 45-year-old patient treated for presenting clinical, paraclinical and radiological manifestations that allow the diagnosis of an acute form of sarcoidosis to be established without confirming by histological study. Its clinical form of expression showed the presence of Löfgren's syndrome with bilateral mediastinal widening due to hilar lymphadenopathy, febrile syndrome, erythema nodosum, and acute arthritis in the lower limbs, which 20-30 percent of patients with sarcoidosis develop. A positron emission tomography scan was performed and its results offered us diagnostic elements typical of a pulmonary inflammatory process far from the characteristics of a malignant neoplastic process(AU)

Diagnostic accuracy of 18F-FDG-PET in abdominal sepsis in rats

Abstract Purpose The objective of this study was to investigate the accuracy of 18F-FDG-PET in the diagnosis of multibacterial abdominal sepsis by cecum ligation and puncture (CLP) in rats. Methods Adult Wistar rats ( Rattus norvegicus ), weighing 227±35g, were allocated into a sepsis group by CLP (n=10) and sham group (n=10). 18F-FDG-PET using microPET was performed on all rats after 24 hours. Results All animals survived for postoperative 24h. The abdomen/liver ratio of the standardized uptake value (SUV) percentage was significantly higher in the sepsis group than in the sham (p=0.004). The ROC curve showed an accuracy of 18F-FDG-PET to detect abdominal sepsis of 88.9% (p=0.001), sensitivity of 90% and specificity of 88.9%. When a cut-off point of 79% of the ratio between the SUV on the abdominal region and liver was established, the sensitivity was 90%, specificity of 88.9%; positive and negative predictive values of 90.0% and 88.9%, respectively. Conclusions The diagnostic accuracy of 18F-FDG-PET in rats with abdominal sepsis was significantly high. It was also demonstrated the predictive ability of the abdomen/liver SUV ratio to diagnose abdominal sepsis. These findings may have implications for the clinical setting, locating septic foci with PETscan.

Tomografía por emisión de positrones con 18F-fluordeoxiglucosa-tomografía computarizada en el diagnóstico del tumor primario de origen desconocido / Value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography ın the diagnosis of carcinoma of unknown primary origin

Introducción: La incidencia de tumores primarios de origen desconocido en pacientes oncológicos es del 0,5 al 7 por ciento en el momento del diagnóstico con una supervivencia a los 3 y 5 años de 11 y 6 por ciento, respectivamente. Objetivo: valorar la utilidad de la técnica PET/CT-FDG (Tomografía por emisión de positrones con 18F-Fluordeoxiglucosa) en el diagnóstico de tumor primario de origen desconocido (TOD). Material y método: Se analizaron retrospectivamente los estudios PET/CT-FDG realizados en pacientes con el diagnóstico de TOD para la búsqueda de tumor primario, con estudios convencionales previos negativos, entre noviembre de 2017 y junio de 2018. El diagnóstico final se estableció mediante confirmación histológica y/o seguimiento clínico/radiológico por 8 meses. Resultados: 42 pacientes fueron estudiados, en 19 estudios PET/CT se evidenciaron focos de captación sugestivos de tumor primario, de los cuales 9 se confirmaron histológicamente como verdaderos positivos y sólo 1 correspondió a un falso positivo. De los 23 pacientes con PET/CT negativos para tumor primario, todos continuaron con diagnóstico de TOD a pesar de las múltiples pruebas diagnósticas. Conclusiones: La técnica PET/CT permitió identificar el 45,2 por ciento de los tumores primarios en la muestra de pacientes, lo que la convierte en una herramienta útil para el diagnóstico en pacientes con metástasis de origen desconocido. Se considera que el PET/CT-FDG debe ser incluido de manera precoz en los algoritmos diagnósticos en Cuba, permitiendo orientar la realización de pruebas complementarias subsiguientes(AU)

Introduction: The incidence of carcinoma of unknown primary origin in oncologic patients is from 0,5 percent to 7 percent at the time of diagnosis with an overall 3-year and 5-year survival of 11 percent and 6 percent, respectively. Objective: To assess the effectiveness of 18 F-FDG-PET/CT (18F-fluorodeoxyglucose posıtron emıssıon tomography) in the diagnosis of carcinoma of unknown primary origin (CUP). Material and Methods: F-FDG-PET/CT studies were conducted in patients with CUP in the search for primary tumor with negative previous conventional studies carried out from November, 2017 to June 2018. The final diagnosis was established by histological confirmation and/or clinical/radiological follow-up during 8 months. Results: A total of 44 patients were studied. There were evidences of suggestive CUP in 19 patients; 9 of them were histologically confirmed as true-positive and only 1 was a false-positive. Of the 23 patients with negative F-FDG-PET/CT studies for primary tumor, all of them continued with the diagnosis of CUP in spite of multiples diagnostic tests. Conclusions: The FDG-PET/CT technique allowed to identify 45,2 percent of the primary tumors in this study, which demonstrates that it is very useful tool for the diagnosis of metastases of unknown origin. It is considered that F-FDG-PET/CT studies should be included earlier in the diagnostic algorithms in Cuba, which will allow to indicate subsequent complementary tests(AU)

Estado actual y perspectivas de la imagen molecular PET en México / Current status and perspectives of PET molecular imaging in Mexico

Resumen La tomografía por emisión de positrones (PET) es una técnica de diagnóstico médico mediante la cual se obtienen imágenes funcionales a partir de registrar la biodistribución espacio-temporal de radiofármacos específicos dirigidos a blancos moleculares específicos, proveyendo información bioquímica a nivel molecular. A principios de la primera década de este siglo XXI, la Facultad de Medicina de la Universidad Nacional Autónoma de México implementó esta técnica de diagnóstico en México, convirtiéndose en pionera en aplicaciones PET en el país y Latinoamérica. Casi dos décadas después, la PET se ha convertido en una herramienta esencial en la clínica médica. En este artículo se describen los antecedentes, el estado actual, las perspectivas de la imagen molecular PET en México y el impacto que ha tenido en el manejo de pacientes con enfermedades oncológicas, neurológicas y cardiológicas.

Abstract Positron-emission tomography (PET) is a medical diagnostic technique by means of which functional images are obtained by recording the spatio-temporal biodistribution of specific radiopharmaceuticals targeted at specific molecular objectives, which provides biochemical information at the molecular level. Early in the first decade of this 21st century, the Faculty of Medicine of the National Autonomous University of Mexico acquired the technology to implement this diagnostic technique in Mexico, thus becoming a pioneer in PET applications in the country and in Latin America. Almost two decades after its implementation in Mexico, PET has become an essential tool in medical clinics. This article describes the background, current state and perspectives of PET molecular imaging in Mexico, and the impact it has had on the management of patients with oncological, neurological and heart diseases.

Sarcoidosis al descubierto: Lo que deberíamos informar en las imágenes torácicas / Sarcoidosis Uncovered: What we should Report in Thoracic Image

La sarcoidosis es una enfermedad granulomatosa no caseificante, multisistémica, de causa desconocida, que compromete al pulmón y a los ganglios linfáticos mediastinales entre el 90 y el 95% de los casos. También puede afectar otros órganos, como las glándulas salivales, piel, ojos, hígado, bazo, corazón, huesos y sistema nervioso central. La sarcoidosis tiene una baja prevalencia en Latinoamérica y es subdiagnosticada debido a la alta frecuencia de otros trastornos similares, como tuberculosis, lepra y micosis profundas. El diagnóstico presuntivo se establece con hallazgos imagenológicos característicos dentro de un contexto clínico apropiado y se confirma con la evidencia histológica de granulomas no caseificantes de células epiteliales, en ausencia de otras etiologías. Los hallazgos torácicos incluyen la afectación pulmonar, ganglionar y bronquial, los cuales son detectados a través de la radiografía (Rx) y tomografía computada (TC) de tórax, siendo esa última más sensible y específica. En este artículo, resaltamos la importancia de reconocer los patrones de presentación típicos y atípicos de la sarcoidosis en Rx y TC, así como la relevancia de las imágenes torácicas como elemento clave en el algoritmo diagnóstico de esa patología. También describimos la utilidad de la resonancia magnética (RM), como método adicional para el diagnóstico en casos de afectación cardíaca y el papel de la tomografía por emisión de positrones (PET-CT) en el seguimiento terapéutico.

Sarcoidosis is a non-caseating granulomatous, multisystemic disease of unknown cause that involves the lung and mediastinal lymph nodes in 90-95% of cases. It can also affect other organs such as the salivary glands, skin, eyes, liver, spleen, heart, bones and the central nervous system. Sarcoidosis has a low prevalence in Latin America and it is underdiagnosed due to the high frequency of other similar disorders such as tuberculosis, leprosy and deep mycosis. The presumptive diagnosis is established based on characteristic imaging findings within an appropriate clinical setting and is confirmed by histological evidence of non-caseating epithelioid cell granulomas, in the absence of other etiologies. Thoracic imaging findings include pulmonary, nodal and bronchial involvement, which are detected on chest radiography (CXR) and computed tomography (CT), this last one having a higher sensitivity and specificity. In this article, we highlight the importance of recognizing the typical and atypical presentation patterns of sarcoidosis on CXR and CT, as well as the relevance of thoracic images as key elements in the diagnostic algorithm of this pathology. We also describe the usefulness of magnetic resonance (MR) imaging as an additional method for diagnosis in cases of cardiac involvement and the role of positron emission tomography (PET-CT) in therapeutic follow-up.

Topography of 11C-Pittsburgh compound B uptake in Alzheimer's disease: a voxel-based investigation of cortical and white matter regions

Objective: To compare results of positron emission tomography (PET) with carbon-11-labeled Pittsburgh compound B (11C-PIB) obtained with cerebellar or global brain uptake for voxel intensity normalization, describe the cortical sites with highest tracer uptake in subjects with mild Alzheimer's disease (AD), and explore possible group differences in 11C-PIB binding to white matter. Methods: 11C-PIB PET scans were acquired from subjects with AD (n=17) and healthy elderly controls (n=19). Voxel-based analysis was performed with statistical parametric mapping (SPM). Results: Cerebellar normalization showed higher 11C-PIB uptake in the AD group relative to controls throughout the cerebral cortex, involving the lateral temporal, orbitofrontal, and superior parietal cortices. With global uptake normalization, greatest cortical binding was detected in the orbitofrontal cortex; decreased 11C-PIB uptake in white matter was found in the posterior hippocampal region, corpus callosum, pons, and internal capsule. Conclusion: The present case-control voxelwise 11C-PIB PET comparison highlighted the regional distribution of amyloid deposition in the cerebral cortex of mildly demented AD patients. Tracer uptake was highest in the orbitofrontal cortex. Decreased 11C-PIB uptake in white-matter regions in this patient population may be a marker of white-matter damage in AD.

Qual o valor da cintilografia de perfusão e PET cardíaco na miocardiopatia hipertrófica / What is the value of perfusion scintigraphy and cardiac PET in hypertrophic cardiomyopathy

A miocardiopatia hipertrófica é a cardiopatia hereditária mais comum e acomete cerca de 1:500 indivíduos na população geral. O diagnóstico, que nem sempre é simples pela variação fenotípica e pela concomitância de outras patologias, baseia-se, inicialmente, em critérios eletrocardiográficos e ecocardiográficos, e na ausência de outras doenças que cursem com hipertrofia ventricular. Tendo como base celular o desarranjo miofibrilar e a fibrose com alterações hemodinâmicas decorrentes, a miocardiopatia hipertrófica pode revelar isquemia miocárdica (não relacionada à aterosclerose) e morte súbita. Assim, a avaliação da repercussão funcional por meio da cintilografia de perfusão miocárdica pela técnica Single Photon Emission Computed Tomography (SPECT) tem ganhado espaço, uma vez que 25% dos pacientes com miocardiopatia hipertrófica demonstram defeitos de perfusão fixos ou isquêmicos. Neste âmbito, notam-se alterações perfusionais que não estão necessariamente associadas ao tipo de miocardiopatia hipertrófica, mas conseguem predizer morbimortalidade nestes indivíduos. Outra técnica cintilográfica mais recente é a tomografia por emissão de pósitrons (PET), que se destaca na avaliação da microcirculação, na reserva de fluxo coronário e no metabolismo miocárdico. Em pacientes com miocardiopatia hipertrófica, estudos têm demonstrado resultados desfavoráveis quanto menores o fluxo sanguíneo miocárdico e a reserva de fluxo coronário. A avaliação miocárdica metabólica pela PET parece útil no entendimento fisiopatológico desta doença e na avaliação prognóstica da ablação alcoólica, procedimento realizado em formas obstrutivas graves. Assim, esta revisão aborda o papel da cardiologia nuclear pelas técnicas SPECT e PET miocárdico na avaliação diagnóstica, prognóstica e terapêutica da miocardiopatia hipertrófica