Aumento de la confianza en la interpretación del PET con 18F-Florbetaben: “machine learning” basado en la aproximación cuantitativa / Increasing the confidence of 18F-florbetaben PET interpretations: Machine learning quantitative approximation

Objetivo: Determinar el valor a-adido de los parámetros semicuantitativos en el análisis visual y estudiar los patrones del depósito cerebral de 18F-Florbetaben. Material y métodos: Análisis retrospectivo de pacientes con deterioro cognitivo leve o demencia de origen incierto procedentes de un estudio multicentrico. Los PET con 18F-Florbetaben fueron interpretados de forma visual por dos observadores independientes, analizando las regiones “diana” con la finalidad de calcular el acuerdo interobservador. Se realizó análisis semicuantitativo de todas las regiones corticales con respecto a tres regiones de referencia para obtener índices de captación (SUVRs). Se analizó la capacidad de los SUVRs para predecir el resultado de la interpretación visual, la posibilidad de depósito preferencial del radiotrazador en algunas regiones “diana” así como las diferencias interhemisféricas. Resultados: Se evaluaron 135 pacientes. En la valoración visual, 72 estudios se clasificaron como positivos. El acuerdo interobservador fue excelente. Todos los SUVRs fueron significativamente superiores en pacientes con PET positivos con respecto a los negativos. Las regiones corticales correspondientes al área prefrontal y al cingulado posterior mostraron la mejor correlación con la evaluación visual, seguidas por la valoración integrada cortical. Usando análisis de ROC, los SUVRs obtenidos en las mismas regiones “diana” mostraron la mejor capacidad diagnóstica. Conclusiones: La información obtenida de las regiones “diana” parece ser de ayuda en la clasificación visual, basado en un depósito preferencial de amiloide, lo que permitiría el “machine learning”. El depósito de amiloide, aunque difuso en todas las regiones corticales, parece no ser uniforme ni simétrico (AU)

Aim: To assess the added value of semiquantitative parameters on the visual assessment and to study the patterns of 18F-Florbetaben brain deposition. Materials and methods: Retrospective analysis of multicenter study performed in patients with mild cognitive impairment or dementia of uncertain origin. 18F-Florbetaben PET scans were visually interpreted by two experienced observers, analyzing target regions in order to calculate the interobserver agreement. Semiquantification of all cortical regions with respect to three reference regions was performed to obtain standardized uptake value ratios (SUVRs). The ability of SUVRs to predict the visual evaluation, the possibility of preferential radiotracer deposition in some target regions and interhemisphere differenceswere analyzed. Results: 135 patients were evaluated. In the visual assessment, 72 were classified as positive. Interobserver agreement was excellent. All SUVRs were significantly higher in positive PET scans than in negative ones. Prefrontal area and posterior cingulate were the cortical regions with the best correlations with the visual evaluation, followed by the composite region. Using ROC analysis, the SUVRs obtained in same target locations showed the best diagnostic performance. Conclusions: The derived information from target regions seems to help the visual classification, based on a preferential amyloid deposit, allowing machine learning. The amyloid deposit, although diffuse in all cortical regions, seems not to be uniform and symmetric (AU)

Global heterogeneity assessed with 18F-FDG PET/CT. Relation with biological variables and prognosis in locally advanced breast cancer. / Medidas de heterogeneidad global y esfericidad con 18F-FDG PET/TC en el cáncer de mama: relación con la biología tumoral, valor predictivo y pronóstico.

AIM: To analyze the relationship between measurements of global heterogeneity, obtained from 18F-FDG PET/CT, with biological variables, and their predictive and prognostic role in patients with locally advanced breast cancer (LABC). MATERIAL AND METHODS: 68 patients from a multicenter and prospective study, with LABC and a baseline 18F-FDG PET/CT were included. Immunohistochemical profile [estrogen receptors (ER) and progesterone receptors (PR), expression of the HER-2 oncogene, Ki-67 proliferation index and tumor histological grade], response to neoadjuvant chemotherapy (NC), overall survival (OS) and disease-free survival (DFS) were obtained as clinical variables. Three-dimensional segmentation of the lesions, providing SUV, volumetric [metabolic tumor volume (MTV) and total lesion glycolysis (TLG)] and global heterogeneity variables [coefficient of variation (COV) and SUVmean/SUVmax ratio], as well as sphericity was performed. The correlation between the results obtained with the immunohistochemical profile, the response to NC and survival was also analyzed. RESULTS: Of the patients included, 62 received NC. Only 18 responded. 13 patients relapsed and 11 died during follow-up. ER negative tumors had a lower COV (p=0.018) as well as those with high Ki-67 (p=0.001) and high risk phenotype (p=0.033) compared to the rest. No PET variable showed association with the response to NC nor OS. There was an inverse relationship between sphericity with DFS (p=0.041), so, for every tenth that sphericity increases, the risk of recurrence decreases by 37%. CONCLUSIONS: Breast tumors in our LABC dataset behaved as homogeneous and spherical lesions. Larger volumes were associated with a lower sphericity. Global heterogeneity variables and sphericity do not seem to have a predictive role in response to NC nor in OS. More spherical tumors with less variation in gray intensity between voxels showed a lower risk of recurrence.

18F-FDG PET/contrast enhanced CT in the standard follow-up of patients with lymphoma. / 18F-FDG PET/TC con contraste intravenoso en el seguimiento estandarizado de pacientes con linfoma.

AIM: To assess the diagnostic accuracy of 18F-FDG PET/contrast enhanced computed tomography (ceCT) in the detection of asymptomatic recurrences in patients with lymphoma. MATERIAL AND METHODS: Patients with lymphoma and clinical complete remission underwent 18F-FDG PET/ceCT for standard follow-up.18F-FDG PET and ceCT were evaluated blindly by two independent observers, and classified as positive or negative for recurrence. Additionally a combined evaluation of both techniques was performed. The final diagnosis was established by histopathological analysis or a clinical follow-up longer than 6 months. Statistical diagnostic parameters and concordance levels between both diagnostic techniques were calculated. RESULTS: A total of 114 explorations on 90 patients were analyzed. Only 4 patients were diagnosed as asymptomatic recurrence during the follow-up. 18F-FDG PET/ceCT, 18F-FDG PET and ceCT showed an association with the final diagnosis (p=0.002 and χ2=11.96; p<0.001 and χ2=15.60; p=0.001 and χ2=11.96, respectively). The concordance between 18F-FDG PET and ceCT was moderate/high and significant (kappa=0.672; p<0.001). A sensitivity and specificity of 50% and 88% was obtained for the 18F-FDG PET/ceCT civ, 50% and 93% for the 18F-FDG PET, and 50% and 91% for the ceCT. CONCLUSION: The combined use of 18F-FDG PET/ceCT did not offer any advantage compared to any isolated diagnostic technique in the detection of asymptomatic lymphoma recurrence.

Pneumomediastinum and pneumothorax during emergency tracheotomy under spontaneous ventilation: Macklin meets Müeller?

Potentially serious complications associated to emergency tracheotomy continue being a matter of concern. We review the pathogenesis of gas leakage in this setting and discuss about the possible mechanisms involved in its cause. We present two cases of pneumomediastinum, subcutaneous emphysema and pneumothorax in the context of emergency tracheotomy under spontaneous ventilation, finally resolved by chest drainage. The combination of overly negative pleural pressures due to extreme inspiratory efforts in the context of an almost completely obstructed airway together with over-pressurized alveoli because of gaseous entrapment secondary to serious expiratory obstruction appears to be the most plausible primary cause of air leaks in our patients. Understanding the underlying mechanisms evolved in its production will help clinicians to suspect and diagnose this phenomenon.

Functionalizing Ti-surfaces through the EPD of hydroxyapatite/nanoY2O3.

Ceramic materials for skeletal repair and reconstruction are expanding to a number of different applications. Present research is addressing new compositions and performances to promote osseo-integration through metal coatings. Nanotechnology plays a key role in this research because nanostructures can be introduced into implants to functionalize them and/or to enhance their properties, such as the thermal or mechanical response. In this work, the insertion of Y(2)O(3) nanoparticles into a hydroxyapatite (HA) coating of Ti using colloidal processing technology was developed. The suspensions of HA and Y(2)O(3) nanoparticles were formulated with a focus on zeta potential, particle size distribution, and viscosity for the codeposition of both phases by electrophoresis. The microstructure of the nanocomposite coating was optimized by adjusting the main parameters of the electrophoretic deposition process. A threshold value of the applied electric field for the composite shaping was identified. The results demonstrate that the Y(2)O(3) nanoparticles are homogeneously distributed in the coating and decrease in concentration as the distance from the substrate increases. As a consequence of the presence of the Y(2)O(3), delays in the HA thermal decomposition and the improvement of metal-ceramic joining were observed.

Enfermedad de Paget de la mama: análisis de una serie de 27 casos / Paget's disease of the breast: analysis of a series of 27 patients

Objetivo: Analizar las características de una serie, con especial referencia a su histogénesis y las posibilidades de la cirugía conservadora. Material y métodos: Se revisó a 27 pacientes portadoras con cáncer de mama (CM) y afectación del pezón con características de enfermedad de Paget (EP). Resultados: Las pacientes tenían una media de 56,5 años, los motivos de consulta fueron: eccema de pezón (48,1%), presencia de tumor mamario (26%) y secreción por el pezón (18,5%). El examen físico advirtió la lesión eccematosa en 26/27 casos. En 11 casos la imagen mamográfica se localizó a nivel retroareolar, en 13 casos distal al pezón y en 3 casos la mamografía fue normal. En 15 casos correspondió a un carcinoma intraductal, y en los 12 restantes a carcinoma ductal infiltrante. En uno la EP fue hallazgo del estudio seriado de la pieza de mastectomía. Se practicó una cirugía conservadora en 5 casos y mastectomía en 22 (6 con reconstrucción inmediata). Tras 6,5 años de seguimiento medio, 2 pacientes presentaron diseminación a distancia y una de las pacientes sometida a cirugía conservadora presentó recidiva local. Conclusiones: La EP representa el 1,4 % de los CM en nuestra serie y el signo diagnóstico característico es el eccema de pezón-aréola. La mamografía muestra una baja sensibilidad diagnóstica; se puede recurrir a la resonancia magnética en los casos de EP sin patología mamográfica y se debe realizar biopsia de la lesión ante la menor duda diagnóstica. El tratamiento más utilizado fue la mastectomía, y se recurrió a la cirugía conservadora en casos seleccionados de EP limitada al pezón, o con lesión subareolar circunscrita, conociendo los riesgos de un tumor subyacente inadvertido

Objective: To analyze the characteristics of a series, with special reference to histogenesis and the possibilities of conservative surgery. Material and methods: We reviewed 27 patients with breast cancer, nipple involvement and characteristics of Paget's disease. Results: The mean age of the patients was 56.5 years. Reasons for consulting were eczema of the nipple (48.1%), breast tumor (26%), and nipple secretion (18.5%). Physical examination revealed an eczematous lesion in 26/27 patients. The mammographic image was localized in the retroareolar area in 11 patients, distal to the nipple in 13 patients and was normal in three patients. Intraductal carcinoma was found in 15 patients and invasive ductal carcinoma in the remaining 12 patients. In one patient, Paget's disease was detected on examination of serial sections of the mastectomy specimen. Conservative surgery was performed in five patients and mastectomy in 22 (six with immediate reconstruction). After a mean follow-up of 6.5 years, distant dissemination occurred in two patients and local recurrence occurred in one patient who underwent conservative surgery. Conclusions: Paget's disease represented 1.4% of breast carcinoma in our series and the characteristic diagnostic sign was eczema of the nipple-aureola. Mammography showed low diagnostic sensitivity. Magnetic resonance imaging should be used in patients with Paget's disease without breast abnormalities. Biopsy of the lesion should be performed when there is diagnostic doubt. The most common treatment was mastectomy. Conservative surgery can be used in selected patients with Paget's disease limited to the nipple or with a circumscribed subareolar lesion, although the risk of an underlying tumor must be taken into account

Endometrial blood flow mapping using transvaginal power Doppler sonography in women with postmenopausal bleeding and thickened endometrium.

OBJECTIVE: To evaluate the role of transvaginal power Doppler sonography to discriminate between benign and malignant endometrial conditions in women presenting with postmenopausal bleeding and thickened endometrium at baseline sonography. METHODS: Ninety-one postmenopausal women (median age, 58 years; range, 47-83 years) presenting with uterine bleeding and a thickened endometrium (> or = 5-mm double-layer endometrial thickness) on transvaginal sonography were included in this prospective study. Endometrial blood flow distribution was assessed in all patients by power Doppler immediately after B-mode transvaginal sonography. Three different vascular patterns were defined: Pattern A: multiple-vessel pattern, Pattern B: single-vessel pattern and Pattern C: scattered-vessel pattern. Histological diagnoses were obtained in all cases. No patient taking tamoxifen citrate or receiving hormone replacement therapy was included. RESULTS: Histological diagnoses were as follows: endometrial cancer: 33 (36%), endometrial polyp: 37 (41%), endometrial hyperplasia: 14 (15%), endometrial cystic atrophy: 7 (8%). Blood flow was found in 97%, 92%, 79% and 85% of cases of carcinoma, polyp, hyperplasia and endometrial cystic atrophy, respectively. A total of 81.3% of vascularized endometrial cancers showed Pattern A, 97.1% of vascularized polyps exhibited Pattern B and 72.7% of vascularized hyperplasias showed Pattern C. Sensitivity and specificity for endometrial cancer were 78.8% and 100%. For endometrial polyp these respective values were 89.2% and 87% and for hyperplasia they were 57.1% and 88.3%. CONCLUSIONS: Transvaginal power Doppler blood flow mapping is useful to differentiate benign from malignant endometrial pathology in women presenting with postmenopausal bleeding and thickened endometrium at baseline sonography.

Nuevo sistema de puntuación ecográfico para el diagnóstico diferencial de las tumoraciones anexiales / New ultrasonographic score for the differential diagnosis of annexal tumors

Objetivo: Diseñar y evaluar una nueva puntuación ecográfica para predecir malignidad en tumores anexiales. Métodos: En este estudio se usaron los datos ecográficos y Doppler de 705 tumores anexiales (141 malignos y 564 benignos) evaluados entre enero de 1995 y julio 2001 para diseñar una puntuación ecográfica. Los datos analizados fueron edad, volumen tumoral, grosor de pared, presencia de septos gruesos, presencia de papilas gruesas, presencia de áreas sólidas, ecogenicidad, presencia de flujo, localización del flujo, cantidad de flujo y velocimetría que se introdujeron en un análisis de regresión logística multivariante. Resultados: En el análisis de regresión sólo quedaron retenidos los siguientes parámetros: presencia de papilas gruesas (odds ratio [OR] = 1,9), áreas sólidas (OR = 8,6), flujo central (OR = 15,5) y velocimetría de alta velocidad-baja resistencia (OR = 5,3). Mediante curva ROC se determinó que el mejor punto de corte era 6 (sensibilidad del 90 per cent; falsos positivos del 7,6 per cent). Conclusiones: La nueva puntuación propuesta es sencilla, basada en un análisis de regresión logística y ofrece un alto rendimiento diagnóstico. (AU)

Valor clínico de la tomografía de emisión de positrones con f-18-fdg en el seguimiento de pacientes con cáncer de ovario / Clinical value of positron emission tomography with f-18-fdg in the follow up of patients with cancer of the ovary

Fundamento. La tomografía por emisión de positrones con flúor-18-desoxiglucosa (PET-FDG) es una técnica eficaz en la detección de tejido tumoral. El objetivo del trabajo fue evaluar la PET-FDG en el diagnóstico de enfermedad residual o recidiva en pacientes con cáncer de ovario. Material y métodos. Se incluyeron un total de 24 pacientes diagnosticadas y tratadas por cáncer de ovario con cirugía y posterior quimioterapia. En 12 pacientes el estudio se realizó previo a la cirugía de second-look y en las otras 12 tras objetivarse en el seguimiento un aumento del marcador tumoral. En todas las pacientes se realizó TAC abdomino-pélvico, determinación de los niveles séricos de CA-125 y PET-FDG de tórax, abdomen y pelvis. La PET-FDG se valoró de forma cualitativa, mediante el estudio visual de las imágenes, y cuantitativa mediante el SUV o valor estándar de captación. El diagnóstico definitivo se confirmó mediante el estudio anatomopatológico en 13 casos y en el resto por seguimiento clínico con una media de 11,2ñ5,4 meses (rango 6-24).Resultados. Se consideró positivo un valor de CA-125 superior a 35 UI/ml, obteniendo una sensibilidad del 77 por ciento y una especificidad del 100 por ciento. La sensibilidad del TAC fue del 23 por ciento y la especificidad 91 por ciento. Con la PET-FDG la sensibilidad fue del 92 por ciento y la especificidad del 90 por ciento. Se consideró patológico un valor SUV 3, obteniéndose los mismos resultados que con la valoración visual. La PET-FDG fue positiva en 5 pacientes con TAC no concluyente, 4 con TAC negativo y 2 con CA-125 negativo. Conclusión. Estos resultados preliminares sugieren que la PET-FDG puede ser útil en el seguimiento de pacientes tratadas por cáncer de ovario. La PET-FDG puede ser especialmente eficaz en la diferenciación entre enfermedad residual o recurrencia frente a secuelas del tratamiento cuando la TAC no es concluyente debido a la distorsión anatómica. La PETFDG puede ser más sensible que la elevación del marcador y ante una elevación de éste permite la localización no invasiva de la enfermedad (AU)

[Clinical value of positron emission tomography with F-18-FDG in the follow up of patients with cancer of the ovary]. / Valor clínico de la tomografía de emisión de positrones con F-18-FDG en el seguimiento de pacientes con cáncer de ovario.

BACKGROUND: Positron emission tomography with fluor-18-deoxyglucose (PET-FDG) is an efficient technique for the detection of tumoural tissue. The aim of the paper is to evaluate the PET-FDG in the diagnosis of residual disease or relapse in patients with cancer of the ovary. METHODS: A total of 24 patients, diagnosed and treated for cancer of the ovary with surgery and subsequent chemotherapy, were included. With 12 patients the study was carried out prior to second-look surgery, and with the other 12 after objectivising an increase of the tumoural marker in the follow up. Abdominal-pelvic CAT, determination of the seric levels of CA-125 and PET-FDG of thorax, abdomen and pelvis were carried out on all patients. The PET-FDG was evaluated in a qualitative way through the visual study of the images, and quantitatively through the SUV or standard uptake value. The definitive diagnosis was confirmed through an anatomopathological study in 13 cases and through clinical follow up in the rest with an average of 11.2+/-5.4 months (range 6-24). RESULTS: A CA-125 value higher than 35 UI/ml was considered positive, obtaining a sensitivity of 77% and a specificity of 100%. The sensitivity of the CAT was 23% and the specificity 91%. With the FDG-PET sensitivity was 92% and the specificity 90%. A SUV value >or= 3 was considered pathological, obtaining the same results as with the visual evaluation. The FDG-PET was positive in 5 patients with non-conclusive CAT, 4 with negative CAT and 2 with negative CA-125. CONCLUSION: These preliminary results suggest that the FDG-PET could be useful in the detection of disease in the follow up of patients treated for cancer of the ovary. The FDG-PET could be efficient in the differentiation between residual disease or recurrence, as opposed to sequels to the treatment, when the CAT is not conclusive due to anatomical distortion, since it permits the detection of tumoural lesions undetected by the radiological image techniques but metabolically active. The FDG-PET could be more sensitive than an increased marker value, and facing an increase of the latter it permits a non-invasive localisation of the disease.

Sonographic features of ovarian cystadenofibromas: spectrum of findings.

OBJECTIVE: To describe the sonographic characteristics of ovarian cystadenofibromas. METHODS: We conducted a retrospective study of 23 ovarian tumors histopathologically confirmed as ovarian cystadenofibromas that were preoperatively evaluated by transvaginal color Doppler sonography. RESULTS: In all cases the mass was predominantly cystic. Septations appeared in 30.4% of the tumors. Papillary projections or solid nodules appeared in 56.5% of the cases. The most frequent appearance was a unilocular complex cystic mass. In 47.8% of the tumors, vascularization was detected, having a typical pattern of peripheral vascularization with scattered vessels of high blood flow impedance. CONCLUSIONS: We have described the sonographic spectrum of findings of ovarian cystadenofibromas. The most frequent appearance was a unilocular cystic mass with gross papillary projections or solid nodules. In almost half of the tumors, vascularization could be detected.

Risk-taking restraints in a bird with reduced egg-hatching success.

Risk taking, as is any other phenotypic and/or behavioural trait, is determined by proximate constraints related to time or resource availability and by evolutionary adaptive restraints related to the differences in the costs of risk taking and its benefits in terms of fitness. Because risk taking is influenced by many confounding variables related to experimental design, environment, parents and offspring, few field studies have been reported which unambiguously separate the effects of restraints from those of constraints. We compared parental risk taking in blue tits (Parus caeruleus) during brood defence towards a nest predator in broods with experimentally reduced and natural egg-hatching success leaving the original number of eggs in the nest. The experimentally reduced broods had more time or resources available and lower risk-taking benefits compared to the control broods. 'Constraint' would predict more risk taking in broods having experimentally reduced egg-hatching success, whereas 'restraint' would predict the opposite effect with more risk taking in broods with natural egg-hatching success. We report, to our knowledge, the first field study experimentally demonstrating a brood defence restraint in response to reduced egg-hatching success. This demonstration was only possible after controlling for more than 20 potential confounding variables showing once more how complicated it is to separate proximate from evolutionary levels of analyses in natural populations.

Transvaginal color Doppler ultrasonography and CA-125 in suspicious adnexal masses.

OBJECTIVE: To compare diagnostic performance of color Doppler ultrasound and CA-125 in suspicious adnexal masses on B-mode sonography. MATERIALS AND METHODS: Data on 94 patients (mean age: 47.4 years, range: 17-79 years. Fifty-two (55.3%) premenopausal and 42 (44.7%) postmenopausal women) managed in our institution because of a suspicious adnexal mass were reviewed. All patients were evaluated by transvaginal color Doppler ultrasonography (CD) and serum CA-125 level determination prior to surgery. Definitive histopathological diagnosis was obtained in each case. Sonographic morphology evaluation was suspicious in all cases. CD was considered as suspicious when flow was detected and the lowest RI found was < or = 0.45. CA-125 cut-off was > or = 35 UI/ml. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each method and compared. ROC analysis was performed for RI and CA-125. Areas under curve (AUC) were calculated and compared. RESULTS: Fifty-six (59.6%) tumors were found to be malignant and 38 (40.4%) benign. Sensitivity, specificity, PPV and NPV for CD were 87.5% (95% CIs: 75.3-94.4), 84.2% (95% CIs: 68.7-94), 89.1% (95% CIs: 77.7-95.9) and 82.1% (95% CIs: 66.5-92.5), respectively. Sensitivity, specificity, PPV and NPV for CA-125 were 83.9% (95% CIs: 71.7-92.4), 68.4% (95% CIs: 51.3-82.5), 79.7% (95% CIs: 66.2-89) and 74.3% (95% CIs: 56.7-87.5), respectively. Sensitivity, PPV and NPV were not statistically different. CD had higher specificity (P = 0.01). AUC curve for Doppler (0.75) was significantly higher than for CA-125 (0.61) (P = 0.0002). CONCLUSIONS: Our results indicate that color Doppler ultrasound has a better diagnostic performance as compared with CA-125, being significantly more specific.