Male flight phenology of the European grapevine moth Lobesia botrana (Lepidoptera: Tortricidae) in different wine-growing regions in Spain.

Lobesia botrana is the most significant pest of grape berries in Spain. Further knowledge of its phenology would enable wine growers to decide on an optimal treatment schedule. The aim of this study is, therefore, to predict the flight peaks of L. botrana in seven wine-growing regions of Spain. The main goal is to provide a prediction model based on meteorological data records. A logistic function model, based on temperature and humidity records, together with an exhaustive statistical analysis, were used to compare the wine-growing regions in which the male flight phenology of L. botrana displays similar patterns and to sort them into groups. By doing so, a joint study of the dynamics of the moth is possible in the regions within each group. A comparison of the prediction errors before and after applying the Touzeau model confirmed that the fit of the latter model is not sufficiently accurate for the regions under study. Moth flight predictions with the logistic function model are good, but accuracy may still be improved by evaluating other non-biotic and biotic factors.

Correlation between Alt a 1 levels and clinical symptoms in Alternaria alternata-monosensitized patients.

BACKGROUND: Alternaria alternata is a risk factor for developing asthma.Alt a 1, which has been described as the major allergen in A alternata, shows a good correlation with A alternata spores only when they have germinated. OBJECTIVES: The objective of this study was to determine the correlation between spore counts and clinical symptoms in patients with allergic asthma and/or rhinitis monosensitized to A alternata. METHODS: Two types of samplers were used to determine exposure: a Burkard spore trap to collect A alternata spores and a high-volume air sampler to collect airborne particles. A total of 366 air filters were collected. Alt a 1 levels were measured by monoclonal antibody-based enzyme-linked immunosorbent assay. Eighteen monosensitized patients were asked to record their daily symptoms throughout the year. RESULTS: A alternata spores were detected throughout the year, whereas Alt a 1 was detected only between March and December. Symptoms showed positive and significant correlations with spore counts (r=0.459, P<.001), and Alt a 1 levels (r=0.294, P<.001). The correlation between spores and Alt a 1 was low. The negative binomial model proved that an increase of 10 pg/m3 in Alt a 1 levels increased the number of symptoms at a 3-day lag by 5%. CONCLUSIONS: In patients who are allergic to A alternata, Alt a 1 levels can be considered an important marker for predicting the risk of respiratory symptoms.

Diagnostic methodology in labelled leukocyte scan for prosthetic / non-prosthetic osteoarticular infection: Visual or semi-quantitative analysis? One- or two-day protocol? / Metodología de la gammagrafía con leucocitos marcados en el diagnóstico de infección osteoarticular protésica/no protésica: ¿análisis visual o semicuantitativo? ¿Protocolo de uno o 2 días?

OBJECTIVE: As scarce literature on the topic is available, we aimed to compare diagnostic utility of semi-quantitative versus visual analysis in labelled white blood cell scintigraphy (WBCS) for osteoarticular infection. One-day and two-day protocols were assessed, particularly in orthopaedic devices. MATERIAL AND METHODS: Prospective study of 79 consecutive patients with suspected osteoarticular infection. In all patients, WBCS were performed at 30min, 4h, 8h and 24h. Images were analysed by grouping in two protocols: one-day-protocol (experts evaluated 30min, 4h and 8h planar images) and two-day-protocol (experts evaluated 30min, 4h and 24h planar images). Planar images were interpreted qualitative and semiquantitatively and also were compared grouping patients with and without orthopaedic devices. To find which cut-off value of the percentage variation could predict of osteoarticular infection, multiple cut-off values were calculated in both protocols from the Youden index. Three blinded readers analysed the images. RESULTS: Comparing final diagnosis visual analysis of the one-day-protocol provided better results with sensitivity of 95.5%, specificity of 93% and diagnostic accuracy of 93.7% (P<.01) than the two-day-protocol with values of 86.4%, 94.7% and 92.4%, respectively (P<.01). For semi-quantitative analysis, the one-day-protocol also obtained better results with sensitivity of 72.7%, specificity of 78.9% and accuracy of 77.2% (P<.01) than two-day-protocol (no significant results; P=.14), especially in the group of patients with orthopaedic devices (sensitivity of 100%, specificity of 79.5% and accuracy of 82.7%; P<.01). CONCLUSIONS: Most accurate approach in the diagnosis of osteoarticular infection corresponded to visual analysis in one-day-protocol that showed greater sensitivity and specificity than semi-quantitative analysis. Semi-quantitative analysis only could be useful when visual analysis is doubtful. In patients with joint prostheses, an increase in percentage variation above 9% obtained maximum sensitivity and negative predictive value.

Optimizing the test power for a radiation retention model in the human body.

The model that describes the retention in lungs of radioisotope particles is studied in this paper, considering the situation of an accident in facilities that handle radioactive materials. Optimal times to make the bioassays are computed for D- and c-optimality, and efficiencies for the computed designs are provided and compared. Moreover, the test power is checked by means of simulations and replications. After that the inverse of the Fisher information matrix is compared to an estimation of the covariance matrix of the parameters. Finally, a study taking into consideration the randomness of the designs space is performed.

Association of laboratory and radiologic parameters in the diagnosis of acute cholecystitis. / Asociación de parámetros analíticos y radiológicos en el diagnóstico de la colecistitis aguda.

INTRODUCTION AND OBJECTIVES: There is currently more evidence suggesting that early surgery should be the treatment of choice for acute calculous cholecystitis, although initial conservative treatment is also reported to be safe. Treatment decision depends on the conditions of the patient, surgical experience, and hospital infrastructure, given that early surgery cannot always be carried out. The aim of the present study was to correlate C-reactive protein values with other variables to determine those situations in which surgery cannot be delayed. MATERIALS AND METHODS: A retrospective study was conducted on patients admitted to the hospital from the emergency service with the diagnosis of acute calculous cholecystitis. The patients were divided into 2groups: 1) patients that required urgent cholecystectomy and 2) patients that responded well to conservative medical treatment and later underwent deferred cholecystectomy. RESULTS: A total of 238 patients (♂ 54.6%, ♀ 45.4%) were analyzed. Urgent surgery was performed on 158 patients, whereas the remaining 80 patients were released from the hospital following conservative treatment. The odds ratio of gangrenous cholecystitis presenting in acute cholecystitis for C-reactive protein was calculated in the logistic regression analysis, obtaining an OR of 1.088 and a 95% CI of 1.031-1.121. CONCLUSION: In patients diagnosed with acute calculous cholecystitis, the combination of elevated values of C-reactive protein levels, gallbladder wall thickness, and number of leukocytes was correlated with less favorable clinical and gallbladder histologic states, resulting in a greater need for urgent surgical treatment.

Segmentation of gliomas in 18F-fluorocholine PET/CT. A multiapproach study. / Segmentación de gliomas con PET/TC con 18F-fluorocolina. Estudio multiaproximación.

AIM: Our aim was two-fold, to study the interobserver agreement in tumour segmentation and to search for a reliable methodology to segment gliomas using 18F-fluorocholine PET/CT. METHODS: 25 patients with glioma, from a prospective and non-randomized study (Functional and Metabolic Glioma Analysis), were included.Interobserver variability in tumour segmentation was assessed using fixed thresholds. Different strategies were used to segment the tumours. First, a semi-automatic tumour segmentation was performed, selecting the best SUVmax-% threshold for each lesion. Next we determined a variable SUVmax-% depending on the SUVmax. Finally a segmentation using a fixed SUVmax threshold was performed. To do so, a sampling of 10 regions of interest (ROI of 2.8cm2) located in the normal brain was performed. The upper value of the sample mean SUVmax±3 SD was used as cut-off. All procedures were tested and classified as effective or not for tumour segmentation by two observer's consensus. RESULTS: In the pilot segmentation, the mean±SD of SUVmax, SUVmean and optimal SUVmax-% threshold were: 3.64±1.77, 1.32±0.57 and 21.32±8.39, respectively. Optimal SUVmax-% threshold showed a significant association with the SUVmax (Pearson=-0.653, p=.002). However, the linear regression model for the total sample was not good, that supported the division in two homogeneous groups, defining two formulas for predicting the optimal SUVmax-% threshold. As to the third procedure, the obtained value for the mean SUVmax background+3 SD was 0.33. This value allowed segmenting correctly a significant fraction of tumours, although not all. CONCLUSION: A great interobserver variability in the tumour segmentation was found. None of the methods was able to segment correctly all the gliomas, probably explained by the wide tumour heterogeneity on 18F-fluorocholine PET/CT.

Baseline 18F-Fluorocholine PET/CT and bone scan in the outcome prediction of patients treated with radium 223 dichloride.

AIM: To establish the utility of baseline 18F-Fluorocholine (FCH) PET/CT and bone scintigraphy (BS) in the outcome prediction of patients with castration-resistant prostate cancer and bone metastases (CRPC-BM) treated with 223Ra. METHODS: Prospective, multicenter and non-randomized study (ChoPET-Rad study). FCH PET/CT and BS were performed before the initiation of 223Ra (basal FCH PET/CT and BS). Bone disease was classified attending the number of lesions in baseline BS and PET/CT. FCH PET/CT was semiquantitatively evaluated. Gleason score, baseline levels of prostate-specific antigen (PSA), alkaline phosphatase and lactate dehydrogenase were determined. Progression-free survival (PFS) and overall survival (OS) since the onset of 223Ra treatment was calculated. PFS was defined by PSA rising. Relations between clinical and imaging variables with PFS and OS were evaluated by Pearson, Mann-Whitney tests and Kapplan-Meier analysis. Univariate and multivariate Cox regression analysis was performed. RESULTS: Forty patients were evaluated. The median PFS and OS were of 3.0 ± 2.3 and 23.0 ± 4.2 months, respectively. 33 patients progressed and 13 died during the follow-up. The extension of the bone disease by FCH PET/CT (p = 0.011, χ2 = 10.63), BS (p = 0.044, χ2 = 8.04), SUVmax (p = 0.012) and average SUVmax (p = 0.014) were related to OS. No significant association was found for the PFS. ROC analysis revealed significant association of SUVmax, average SUVmax and basal PSA with OS. Only therapeutic failure was associated with OS in the multivariate analysis (HR = 3.6, p = 0.04). CONCLUSION: FCH PET/CT and BS had prognostic aim in the prediction of OS. None clinical or imaging variable was able to predict the PFS, probably due to the high rate of progressive disease.

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.

Predictive and prognostic potential of volume-based metabolic variables obtained by a baseline 18F-FDG PET/CT in breast cancer with neoadjuvant chemotherapy indication. / Papel predictivo y pronóstico de las variables volumétricas metabólicas obtenidas en la 18F-FDG PET/TC en el cáncer de mama con indicación de quimioterapia neoadyuvante.

AIM: To investigate the usefulness of metabolic variables using 18F-FDG PET/CT in the prediction of neoadjuvant chemotherapy (NC) response and the prognosis in locally advanced breast cancer (LABC). MATERIAL AND METHODS: Prospective study including 67 patients with LABC, NC indication and a baseline 18F-FDG PET/CT. After breast tumor segmentation, SUV variables (SUVmax, SUVmean and SUVpeak) and volume-based variables, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), were obtained. Tumors were grouped into molecular phenotypes, and classified as responders or non-responders after completion of NC. Disease-free status (DFs), disease-free survival (DFS), and overall survival (OS) were assessed. A univariate and multivariate analysis was performed to study the potential of all variables to predict DFs, DFS, and OS. RESULTS: Fourteen patients were classified as responders. Median±SD of DFS and OS was 43±15 and 46±13 months, respectively. SUV and TLG showed a significant correlation (p<0.005) with the histological response, with higher values in responders compared to non-responders. MTV and TLG showed a significant association with DFs (p=0.015 and p=0.038 respectively). Median, mean and SD of MTV and TLG for patients with DFs were: 8.90, 13.73, 15.10 and 33.78, and 90.54 and 144.64, respectively. Median, mean and SD of MTV and TLG for patients with non-DFs were: 16.72, 29.70 and 31.09 and 90.89, 210.98 and 382.80, respectively. No significant relationships were observed with SUV variables and DFs. Volume-based variables were significantly associated with OS and DFS, although in multivariate analysis only MTV was related to OS. No SUV variables showed an association with the prognosis. CONCLUSION: Volume-based metabolic variables obtained with 18F-FDG PET/CT, unlike SUV based variables, were good predictors of both neoadjuvant chemotherapy response and prognosis.

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.

Utility of 18F-FDG-PET/CT in patients suspected of paraneoplastic neurological syndrome: importance of risk classification.

PURPOSE: To assess the diagnostic impact of 18F-FDG-PET/CT in patients suspected of paraneoplastic neurological syndrome (PNS) based on our own pre-test risk classification (PRC). METHODS: A multicenter retrospective longitudinal study was conducted from 2006 to 2014. We designed a seven-point scoring system using the clinical syndrome characteristics [classical (CS) and non-classical syndromes (NCS)] and its location (central, peripheral, in the neuromuscular junction or combined), onconeural antibodies and tumor markers. Patients were classified as low (score 0-2), intermediate (3-4) and high (5-7) pre-test risk of PNS. FDG-PET/CT was classified as negative or positive. Final diagnosis according Graus' criteria (definite, possible or no PNS) was established. Relations between clinical and metabolic variables with the final diagnosis were studied. RESULTS: 73 patients were included, with a follow-up time of 33 months. Eleven (15 %) patients were finally diagnosed with neoplasm (8 invasive cancers). Ultimately, 13 (18 %) and 24 (33 %) subjects were diagnosed as definite or possible PNS. All the patients with final diagnosis of neoplasm had a CS (p = 0.005). PET/CT was helpful to diagnose 6/8 (75 %) invasive cancers. PET/CT findings were associated with the final diagnosis of neoplasm (p = 0.003) and the diagnosis of PNS attending to Graus' criteria (p = 0.019). PRC showed significant association with the final diagnosis of neoplasm and PET/CT results. A majority of patients (10/11) diagnosed of neoplasm had intermediate/high-risk. CONCLUSIONS: Our PRC seems to be a valid tool to select candidates for PET/CT imaging in this setting. PET/CT detected malignancy in a significant proportion of patients with invasive cancer.

Metodología de la gammagrafía con leucocitos marcados en el diagnóstico de infección osteoarticular protésica/no protésica: ¿análisis visual o semicuantitativo? ¿Protocolo de uno o 2 días? / Diagnostic methodology in labelled leukocyte scan for prosthetic / non-prosthetic osteoarticular infection: Visual or semi-quantitative analysis? One- or two-day protocol?

Objetivo: Como hay poca literatura sobre el tema, nos propusimos comparar la utilidad diagnóstica del análisis semicuantitativo versus el análisis visual en la escintigrafía de glóbulos blancos etiquetados (WBCS) para la infección osteoarticular. Se evaluaron protocolos de uno y dos días, en particular en los dispositivos ortopédicos.Material y métodos: Estudio prospectivo de 79 pacientes consecutivos con sospecha de infección osteoarticular. En todos los pacientes, la SCBM se realizó a los 30 min, 4 h, 8 h y 24 h. Las imágenes se analizaron agrupándolas en dos protocolos: protocolo de un día (los expertos evaluaron imágenes planas de 30 min, 4 h y 8 h) y protocolo de dos días (los expertos evaluaron imágenes planas de 30 min, 4 h y 24 h). Las imágenes planas se interpretaron cualitativa y semicuantitativamente y también se compararon agrupando a los pacientes con y sin dispositivos ortopédicos. Para determinar qué valor de corte de la variación porcentual podía predecir la infección osteoarticular, se calcularon múltiples valores de corte en ambos protocolos a partir del índice de Youden. Tres lectores ciegos analizaron las imágenes.Resultados: Comparando el diagnóstico final, el análisis visual del protocolo de un día proporcionó mejores resultados con una sensibilidad del 95,5%, una especificidad del 93% y una precisión diagnóstica del 93,7% (p < 0,01) que el protocolo de dos días con valores del 86,4%, 94,7% y 92,4%, respectivamente (p < 0,01). Para el análisis semicuantitativo, el protocolo de un día también obtuvo mejores resultados con una sensibilidad del 72,7%, una especificidad del 78,9% y una precisión del 77,2% (p < 0,01) que el protocolo de dos días (sin resultados significativos; p = 0,14), especialmente en el grupo de pacientes con aparatos ortopédicos (sensibilidad del 100%, especificidad del 79,5% y precisión del 82,7%; p < 0,01)

Objective: As scarce literature on the topic is available, we aimed to compare diagnostic utility of semi-quantitative versus visual analysis in labelled white blood cell scintigraphy (WBCS) for osteoarticular infection. One-day and two-day protocols were assessed, particularly in orthopaedic devices.Material and methods: Prospective study of 79 consecutive patients with suspected osteoarticular infection. In all patients, WBCS were performed at 30min, 4h, 8h and 24h. Images were analysed by grouping in two protocols: one-day-protocol (experts evaluated 30min, 4h and 8h planar images) and two-day-protocol (experts evaluated 30min, 4h and 24h planar images). Planar images were interpreted qualitative and semiquantitatively and also were compared grouping patients with and without orthopaedic devices. To find which cut-off value of the percentage variation could predict of osteoarticular infection, multiple cut-off values were calculated in both protocols from the Youden index. Three blinded readers analysed the images.Results: Comparing final diagnosis visual analysis of the one-day-protocol provided better results with sensitivity of 95.5%, specificity of 93% and diagnostic accuracy of 93.7% (P<.01) than the two-day-protocol with values of 86.4%, 94.7% and 92.4%, respectively (P<.01). For semi-quantitative analysis, the one-day-protocol also obtained better results with sensitivity of 72.7%, specificity of 78.9% and accuracy of 77.2% (P<.01) than two-day-protocol (no significant results; P=.14), especially in the group of patients with orthopaedic devices (sensitivity of 100%, specificity of 79.5% and accuracy of 82.7%; P<.01).Conclusions: Most accurate approach in the diagnosis of osteoarticular infection corresponded to visual analysis in one-day-protocol that showed greater sensitivity and specificity than semi-quantitative analysis. Semi-quantitative analysis only could be useful when visual analysis is doubtful

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)

Role of 18F-Choline PET/CT in guiding biopsy in patients with risen PSA levels and previous negative biopsy for prostate cancer.

OBJECTIVES: To study 18F-Choline PET/CT in the diagnosis and biopsy guide of prostate cancer (pCa) in patients with persistently high prostate-specific antigen (PSA) and previous negative prostate biopsy. To compare the clinical risk factors and metabolic variables as predictors of malignancy. METHODS: Patients with persistently elevated PSA in serum (total PSA >4ng/mL) and at least a previous negative or inconclusive biopsy were consecutively referred for a whole body 18F-Choline PET/CT. Patient age, PSA level, PSA doubling time (PSAdt) and PSA velocity (PSAvel) were obtained. PET images were visually (positive or negative) and semiquantitatively (SUVmax) reviewed. 18F-Choline uptake prostate patterns were defined as focal, multifocal, homogeneous or heterogeneous. Histology on biopsy using transrectal ultrasound-guided approach was the gold standard. Sensitivity (Se), specificity (Sp) and accuracy (Ac) of PET/CT for diagnosis of pCa were evaluated using per-patient and per-prostate lobe analysis. Receiver-operating-characteristic (ROC) curve analysis was used to assess the value of SUVmax to diagnose pCa. Correlation between PET/CT and biopsy results per-prostate lobe was assessed using the Chi-square test. Univariate and multivariate logistic regression analysis were applied to compare clinical risk factors and metabolic variables as predictors of malignancy. RESULTS: Thirty-six out of 43 patients with histologic confirmation were included. In 11 (30.5%) patients, pCa was diagnosed (Gleason score from 4 to 9). The mean values of patient age, PSA level, PSAdt and PSAvel were: 65.5 years, 15.6ng/ml, 28.1 months and 8.5ng/mL per year, respectively. Thirty-three patients had a positive PET/CT; 18 had a focal pattern, 7 multifocal, 4 homogeneous and 4 heterogeneous. Se, Sp and Ac of PET/CT were of 100%, 12% and 38% in the patient based analysis, and 87%, 29% and 14% in the prostate lobe based analysis, respectively. The ROC curve analysis of SUVmax showed an AUC of 0.568 (p=0.52). On a lobe analysis, poor agreement was observed between PET/CT findings and biopsy results (p=0.097). In the univariate/multivariate analysis, none of clinical and metabolic variables were statistically significant as predictor of pCa. CONCLUSION: Choline PET/CT is a suitable procedure for the detection of pCa in highly selected patients, however, a high rate of false positive should be expected.

Glycolytic activity in breast cancer using 18F-FDG PET/CT as prognostic predictor: A molecular phenotype approach.

AIM: To explore the relationship between basal (18)F-FDG uptake in breast tumors and survival in patients with breast cancer (BC) using a molecular phenotype approach. MATERIAL AND METHODS: This prospective and multicentre study included 193 women diagnosed with BC. All patients underwent an (18)F-FDG PET/CT prior to treatment. Maximum standardized uptake value (SUVmax) in tumor (T), lymph nodes (N), and the N/T index was obtained in all the cases. Metabolic stage was established. As regards biological prognostic parameters, tumors were classified into molecular sub-types and risk categories. Overall survival (OS) and disease free survival (DFS) were obtained. An analysis was performed on the relationship between semi-quantitative metabolic parameters with molecular phenotypes and risk categories. The effect of molecular sub-type and risk categories in prognosis was analyzed using Kaplan-Meier and univariate and multivariate tests. RESULTS: Statistical differences were found in both SUVT and SUVN, according to the molecular sub-types and risk classifications, with higher semi-quantitative values in more biologically aggressive tumors. No statistical differences were observed with respect to the N/T index. Kaplan-Meier analysis revealed that risk categories were significantly related to DFS and OS. In the multivariate analysis, metabolic stage and risk phenotype showed a significant association with DFS. CONCLUSION: High-risk phenotype category showed a worst prognosis with respect to the other categories with higher SUVmax in primary tumor and lymph nodes.

Basal (18)F-FDG PET/CT in follicular lymphoma: A comparison of metabolic and clinical variables in the prognostic assessment.

AIM: To analyze the relationship of clinical variables related to prognosis and tumor burden, with metabolic variables obtained in the staging (18)F-FDG PET/CT, and their value in the prognosis in follicular lymphoma (FL). METHODS: 82 patients with FL, a (18)F-FDG PET/CT at diagnosis and a follow-up for a minimum of 12 months, were retrospectively enrolled in the present study. Clinical variables (Tumor grade, Follicular Lymphoma International Prognostic Index (FLIPI) and Tumor burden) were evaluated. Metabolic variables such as SUVmax in the highest hypermetabolic lesion, extralymphatic locations, number of involved lymph node locations, bone marrow (BM) involvement, PET stage and diameter of the biggest hypermetabolic lesion, were analyzed in order to establish a PET score and classify the studies in low, intermediate and high metabolic risk. Clinical and metabolic variables (included metabolic risk) were compared. The relation among all variables and disease-free survival (DFS) was studied. RESULTS: The 28% of patients had a high-grade tumor. The 30.5% had FLIPI risk low, 29.3% intermediate y 40.2% high. The 42.7% presented a high tumor burden. The PET/CT was positive in 94% of patients. The tumor grade did not show significant relation with metabolic variable. FLIPI risk and tumor burden showed statistical relations with the SUV max and the PET score (p<0.008 and p=0.003 respectively). With respect to DFS, significant differences were detected for the PET stage and FLIPI risk (p=0.015 and p=0.047 respectively). FLIPI risk was the only significant predictor in Cox regression analysis, with a Hazard Ratio of 5.13 between high risk and low risk. CONCLUSION: The present research highlights the significant relation between metabolic variables obtained with FDG PET/CT and clinical variables although their goal as an independent factor of prognosis was not demonstrated in the present work.

Segmentación de gliomas con PET/TC con 18F-fluorocolina. Estudio multiaproximación / Segmentation of gliomas in 18F-fluorocholine PET/CT. A multiapproach study

OBJETIVO: El objetivo fue doble, valorar el acuerdo interobservador en la segmentación tumoral y la búsqueda de una metodología fiable y aplicable en la segmentación de gliomas usando PET/TC con 18F-fluorocolina. MATERIAL Y MÉTODOS: Se incluyeron 25 pacientes con glioma, procedentes de un estudio prospectivo no randomizado (Functional and Metabolic Glioma Analysis). Se analizó la variabilidad interobservador usando umbrales fijos. Diferentes estrategias se emplearon en la segmentación. Primero, se realizó una segmentación semiautomática, seleccionando el mejor umbral del SUVmáx-% para cada lesión. Posteriormente, se determinó una variable del SUVmáx-% dependiente del SUVmáx. Finalmente se realizó una segmentación usando un valor de umbral fijo de SUVmáx. Para ello, se realizó un muestreo de 10 regiones de interés (ROI de 2,8cm2) localizadas en cerebro normal. El valor superior obtenido de la media del muestreo+/-3 desviaciones estándar se usó como valor de corte. Todos los procedimientos fueron testados y clasificados como válidos o no en la segmentación tumoral en consenso por dos observadores. RESULTADOS: En la segmentación piloto, la media+/-DE del SUVmáx, SUVmedio y el umbral del SUVmáx-% fue de 3,64+/-1,77; 1,32+/-0,57 y 2,132+/-8,39, respectivamente. El valor óptimo del umbral SUVmáx-% mostró una asociación significativa con el SUVmáx (Pearson=-0,653; p = 0,002). Sin embargo, el modelo de regresión lineal del total de la muestra no fue bueno lo que justificó la división de la misma en dos grupos homogéneos, definiendo dos fórmulas para predecir el umbral del SUVmáx-%. Para el tercer procedimiento, el valor obtenido de la media SUVmáx+3 DE fue de 0,33. Este valor permitió segmentar correctamente una elevada proporción de casos, aunque no todos. CONCLUSIÓN: Se encontró una gran variabilidad interobservador en la segmentación tumoral. Ninguno de los métodos fue capaz de segmentar correctamente todos los gliomas probablemente debido a la amplia heterogeneidad en la PET/TC con 18F-fluorocolina

AIM: Our aim was two-fold, to study the interobserver agreement in tumour segmentation and to search for a reliable methodology to segment gliomas using 18F-fluorocholine PET/CT. METHODS: 25 patients with glioma, from a prospective and non-randomized study (Functional and Metabolic Glioma Analysis), were included. Interobserver variability in tumour segmentation was assessed using fixed thresholds. Different strategies were used to segment the tumours. First, a semi-automatic tumour segmentation was performed, selecting the best SUVmax-% threshold for each lesion. Next we determined a variable SUVmax-% depending on the SUVmax. Finally a segmentation using a fixed SUVmax threshold was performed. To do so, a sampling of 10 regions of interest (ROI of 2.8cm2) located in the normal brain was performed. The upper value of the sample mean SUVmax+/-3 SD was used as cut-off. All procedures were tested and classified as effective or not for tumour segmentation by two observer's consensus. RESULTS: In the pilot segmentation, the mean+/-SD of SUVmax, SUVmean and optimal SUVmax-% threshold were: 3.64+/-1.77, 1.32+/-0.57 and 21.32+/-8.39, respectively. Optimal SUVmax-% threshold showed a significant association with the SUVmax (Pearson=−0.653, p=.002). However, the linear regression model for the total sample was not good, that supported the division in two homogeneous groups, defining two formulas for predicting the optimal SUVmax-% threshold. As to the third procedure, the obtained value for the mean SUVmax background+3 SD was 0.33. This value allowed segmenting correctly a significant fraction of tumours, although not all. CONCLUSION: A great interobserver variability in the tumour segmentation was found. None of the methods was able to segment correctly all the gliomas, probably explained by the wide tumour heterogeneity on 18F-fluorocholine PET/CT

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 / Global heterogeneity assessed with 18F-FDG PET/CT. Relation with biological variables and prognosis in locally advanced breast cancer

OBJETIVO: Determinar la relación de las medidas de heterogeneidad global y la esfericidad tumoral obtenidas en 18F-FDG PET/TC con variables biológicas, así como su papel predictivo y pronóstico en pacientes con cáncer de mama localmente avanzado (CMLA). MATERIAL Y MÉTODOS: Se incluyeron 68 pacientes con CMLA, con indicación de tratamiento neoadyuvante (TNA) y18F-FDG PET/TC basal procedentes de un estudio prospectivo multicéntrico en curso. Se determinó el perfil inmunohistoquímico [receptores de estrógenos (RE) y de progesterona (RP), expresión del oncogén HER-2, índice de proliferación Ki-67 y grado histológico tumoral], la respuesta al TNA, la supervivencia global (SG) y la supervivencia libre de enfermedad (SLE). Se realizó la segmentación tridimensional de las lesiones, obteniendo variables SUV, volumétricas y de heterogeneidad global, así como la esfericidad. También se analizó la correlación entre los resultados obtenidos con el perfil inmunohistoquímico, la respuesta a la quimioterapia neoadyuvante (QN) y la supervivencia, tanto global (SG) como libre de enfermedad (SLE). RESULTADOS: De las pacientes incluidas, 62 recibieron QN, respondiendo a este solo 18.13 pacientes recidivaron y 11 fallecieron durante el seguimiento. Los tumores que no expresaron RE tuvieron un COV inferior (p = 0,018), así como los de Ki-67 alto (p = 0,001) y los de fenotipo de alto riesgo (p = 0,033) frente al resto. Ninguna variable PET mostró asociación con la respuesta a la QN ni con la SG. La esfericidad y el índice SUVmedio/SUVmáx se relacionaron con la SLE de forma inversa (p = 0,041 y p = 0,055, respectivamente) de modo que, por cada décima que aumenta la esfericidad, el riesgo de recurrencia disminuye en un 37%. CONCLUSIONES: Los tumores de mama localmente avanzados incluidos en nuestra muestra se comportaron como lesiones homogéneas y esféricas. Los de mayor volumen se asociaron con menor esfericidad. Las variables de heterogeneidad global y la esfericidad no parecen tener un papel predictivo en la respuesta a la QN ni en la SG. Los tumores más esféricos y con menor variación en la intensidad de gris entre los vóxeles mostraron un menor riesgo de recurrencia

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