Desenmascarando la polimialgia reumática, papel de la Medicina Nuclear / Decoding polymyalgia rheumatica, the role of Nuclear Medicine Imaging

La polimialgia reumática (PMR) es una enfermedad inflamatoria de las articulaciones que se presenta en pacientes mayores de 50 años con dolor y rigidez matutina prolongada en las cinturas del hombro y la cadera y en el cuello. La falta de hallazgos clínicos específicos, signos de laboratorio, biomarcadores y métodos de imagen establecidos dificulta el diagnóstico de los pacientes con esta enfermedad. La 18F-FDG PET/TC es una técnica de imagen funcional que constituye una herramienta consolidada en Oncología y que también ha demostrado su utilidad en el campo de las enfermedades inflamatorias. El objetivo de este trabajo es presentar evidencia bibliográfica sobre el uso de métodos de imagen molecular como la PET/TC para el diagnóstico precoz, la evaluación de la actividad de la enfermedad y la respuesta terapéutica en la PMR. Al mismo tiempo, se consideran las ventajas, las desventajas y las contraindicaciones de otros métodos (AU)

Polymyalgia rheumatica (PMR) is an inflammatory joint disease that presents in patients older than 50 years with prolonged morning pain and stiffness in the shoulder and hip joints and neck. The lack of specific clinical findings, laboratory signs, biomarkers and established imaging methods makes it difficult to diagnose patients with this disease. 18F-FDG PET/CT is a functional imaging technique that is an established tool in oncology and has also proven useful in the field of inflammatory diseases. The aim of this paper is to present literature evidence on the use of molecular imaging methods such as PET/CT for early diagnosis, assessment of disease activity and therapeutic response in PMR. At the same time, the advantages, disadvantages and contraindications of other methods are considered (AU)

Decoding polymyalgia rheumatica, the role of Nuclear Medicine Imaging.

Polymyalgia rheumatica (PMR) is an inflammatory joint disease that presents in patients older than 50 years with prolonged morning pain and stiffness in the shoulder and hip joints and neck. The lack of specific clinical findings, laboratory signs, biomarkers and established imaging methods makes it difficult to diagnose patients with this disease. 18F-FDG PET/CT is a functional imaging technique that is an established tool in oncology and has also proven useful in the field of inflammatory diseases. The aim of this paper is to present literature evidence on the use of molecular imaging methods such as PET/CT for early diagnosis, assessment of disease activity and therapeutic response in PMR. At the same time, the advantages, disadvantages and contraindications of other methods are considered.

Chronic expanding hematoma.

Chronic expansive hematoma (CEH) is a rare lesion, characterized by the persistence and increase in size of an hematoma for a period greater than one month since the initial hemorrhage. The clinical importance of this pathology is due to the fact that it can simulate malignant soft tissue neoplasms, both clinically as a result of its progressive growth and radiologically for its findings in imaging studies. This article will review three cases of CEH in different scenarios, explaining the radiological findings in different imaging techniques such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and PET-CT.

Valor predictivo de los índices 18F-FDG PET/TC sobre la carga tumoral residual en pacientes con cáncer de mama extenso tratadas con quimioterapia neoadyuvante / Predictive value of 18F-FDG PET/CT indices on extensive residual cancer burden in breast cancer patients treated with neoadjuvant chemotherapy

Objetivo: Investigamos la correlación entre los índices de PET/TC con 18F-FDG y la respuesta patológica en el cáncer de mama tratado con quimioterapia neoadyuvante (QNA), que se puntuó con el sistema de carga de cáncer residual (RCB) después de la cirugía. Nuestro objetivo es detectar antes una carga extensa de cáncer residual mediante el uso de los índices de PET/TC. Métodos: Se recuperaron las características de las pacientes de forma retrospectiva. Se calculó el valor máximo de captación estándar (SUVmáx), el volumen metabólico del tumor (MTV) y los índices de glucólisis total de la lesión (TLG), así como la tasa de reducción (RR) entre la línea de base y la evaluación intermedia, con la exploración FDG PET/TC. Todos los pacientes fueron evaluados según las puntuaciones RCB después de la cirugía. Las respuestas patológicas y los resultados de las mediciones de PET/TC se analizaron con parámetros demográficos y clínicos. Resultados: Un total de 95 pacientes fueron incluidos en el estudio. Según las respuestas patológicas, la distribución de RCB-0, -1, -2, -3 fue de 13 (13,7%), 11 (11,6%), 30 (31,6%) y 41 (43,2%), respectivamente. La supervivencia libre de enfermedad fue significativamente menor en el grupo RCB-3 en comparación con el grupo de respuesta patológica (p=0,01). Según el análisis multivariante, se determinó que el RR del SUVmáx era una variable independiente que predecía la RCB extensa con un valor de corte óptimo del 86% (p<0,05). Conclusiones: Determinamos el RR de SUVmáx como un factor independiente para predecir la carga tumoral residual extensa. Creemos que el RR de SUVmáx es suficiente para predecir la respuesta patológica en la práctica diaria. Además, las mediciones de MTV y TLG no contribuyen adicionalmente al SUVmáx por sí solas y pueden causar una pérdida de trabajo innecesaria (AU)

Aim: We investigated the correlation between 18F-FDG PET/CT indices and pathological response in breast cancer treated with neoadjuvant chemotherapy (NACT) which was scored with Residual Cancer Burden (RCB) system after surgery. Our aim is to detect extensive residual cancer burden earlier by using PET/CT indices. Methods: Characteristics of patients were retrieved retrospectively. Baseline maximum Standart Uptake Value (SUVmax), Metabolic Tumor Volume (MTV) and Total Lesion Glycolysis (TLG) indices and reduction rate (RR) between baseline and interim evaluation were calculated with FDG PET/CT scan. All patients were evaluated according to RCB scores after surgery. Pathological responses and PET/CT measurement results were analyzed with demographic and clinical parameters. Results: A total of 95 patients were included in the study. According to pathological responses, the distribution of RCB-0, -1, -2, -3 were 13 (13.7%), 11 (11.6%), 30 (31.6%), 41 (43.2%), respectively. Disease-free survival was significantly lower in the RCB-3 group compared to the pathological responder group (P=.01). According to multivariate analysis, RR of SUVmax was determined as an independent variable predicting extensive residual cancer burden with an optimal cut-off value of 86% (P<.05). Conclusions: We determined RR of SUVmax as an independent factor for predicting extensive residual tumor burden. We believe that RR of SUVmax is sufficient to predict pathological response in daily practice. In addition, MTV and TLG measurements do not contribute additionally to SUVmax alone and can cause unnecessary labor loss (AU)

The role of 18F-FDG PET/CT metabolic parameters in pediatric lymphoblastic lymphoma.

OBJECTIVE: This retrospective study aimed to evaluate the role of metabolic parameters of 18F-FDG PET/CT in pediatric lymphoblastic lymphoma (LBL). METHODS: Thirty patients with LBL underwent 42 scans. Metabolic parameters including maximum standardized uptake value (SUVmax), total metabolic tumor volume (TMTV), and total lesion glycolysis (TLG) were measured at baseline PET/CT. Univariate and multivariate analysis for survival were performed to assess their prognostic value. Twelve patients underwent PET/CT after reinduction regime, and the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT for predicting relapse were calculated. RESULTS: Patients with stage Ⅳ had a higher TMTV than those with stage III (p = 0.031). Besides, patients with T-LBL or mediastinal involvement had a high TMTV and TLG (p < 0.05). There was no significant difference in PET/CT metabolic parameters between patients with different outcomes (p > 0.05). Children with a low TMTV (<242.91 cm³) had a better 3-year EFS compared with those with a high TMTV (88.9% vs. 56.3%; p = 0.036). SUVmax and TLG were not predictive of EFS (p = 0.874; p = 0.152). However, none of the metabolic parameters of baseline PET/CT were independent prognostic factors for outcomes of pediatric LBL. PET/CT underwent after reinduction regime present with higher sensitivity (50% vs. 0%) and NPV (90% vs. 83.3%) for predicting relapse than CT alone. CONCLUSIONS: Metabolic parameters of baseline PET/CT were not predictive of outcomes in children with LBL. PET/CT done after the reinduction regime had better sensitivity and NPV than CT alone, and a negative scan could be a reliable indicator for sustained remission.

Association of 18F-FDG PET/CT textural features with immunohistochemical characteristics in invasive ductal breast cancer / Asociación de características texturales de PET/TC 18F-FDG con características inmunohistoquímicas en el cáncer de mama ductal invasivo

Objetivo: Este estudio investiga si las características de textura (TF) extraídas de la tomografía por emisión de positrones/tomografía computarizada (PET/TC) con fluoruro-18 fluorodesoxiglucosa (F-18 FDG) están asociadas con las características inmunohistoquímicas (IHC) del carcinoma ductal de mama invasivo (IDBC).Materiales y métodos: Se evaluó la relación de TF con IHC [receptor de estrógeno (ER), receptor de progesterona (PR), receptor 2 del factor de crecimiento epidérmico humano (HER-2), índice de proliferación Ki-67 y grados histológicos] de tumores primarios extirpados únicamente para una evaluación más precisa. Por lo tanto, los pacientes con IDBC en estadio temprano que se sometieron a una exploración por PET/TC con F-18 FDG pre-operatoria para la estadificación se incluyeron en este estudio retrospectivo. La estadificación clínica se realizó de acuerdo con la 8a edición del American Joint Committee on Cancer. El valor máximo de captación estandarizada (SUVmáx) y 37 TF del tumor primario se extrajeron de F-18 FDG PET/TC. Se utilizó la prueba de correlación de rango de Spearman para evaluar la correlación entre TF y SUVmáx. Se generaron curvas de características operativas del receptor para definir el rendimiento diagnóstico de cada parámetro. Entre estos parámetros, aquellos con mayor rendimiento diagnóstico se incluyeron en el modelo de regresión logística multivariante para identificar los predictores independientes de las características histopatológicas.Resultados: Se incluyeron un total de 124 pacientes. La uniformidad del histograma, la energía GLCM y la homogeneidad GLCM mostraron una fuerte correlación negativa con SUVmax, mientras que GLRLM-SRHGE, GLZLM-HGZE, GLRLM-HGRE, GLCM-entropía, GLCM-contraste, histograma-entropía y GLCM-disimilitud mostraron una fuerte correlación positiva. Algunos de los TF se asociaron de forma independiente con ER-negatividad, PR-negatividad, HER-2-positividad y aumento del índice

Objectıves: This study investigates whether textural features (TFs) extracted from 18F-FDG positron emission tomography/computed tomography (PET/CT) are associated with immunohistochemical characteristics (IHCs) of invasive ductal breast carcinoma (IDBC).Materials and methods: The relationship of TFs with IHCs [estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER-2), Ki-67 proliferation index, and histological grades] from solely excised primary tumors were evaluated for a more accurate assessment. Therefore patients with early-stage IDBC who underwent pre-operative 18F-FDG PET/CT scan for staging were included in this retrospective study. The clinical staging was performed according to the 8th edition of the American Joint Committee on Cancer. Maximum standardized uptake value (SUVmax) and 37TFs of the primary tumor were extracted from 18F-FDG PET/CT. Spearman’s rank correlation test was used to evaluate the correlation between TFs and SUVmax. Receiver operating characteristic curves were generated to define the diagnostic performance of each parameter. Among these parameters, those with the highest diagnostic performance were included in the multivariate logistic regression model to identify the independent predictors of histopathological characteristics.Results: A total of 124 patients were included. Histogram-uniformity, grey-level co-occurrence matrix (GLCM), GLCM-energy, and GLCM-homogeneity showed a strong negative correlation with SUVmax, while grey-level run-length matrix (GLRLM), GLRLM-SRHGE, grey-level zone length matrix (GLZLM), GLZLM-HGZE, GLRLM-HGRE, GLCM-entropy, GLCM-contrast, histogram-entropy, and GLCM-dissimilarity showed a strong positive correlation. Some of the TFs were independently associated with ER-negativity, PR-negativity, HER-2-positivity, and increased Ki-67 proliferation index (GLCM-contrast, GLZLM-GLNU, histogram-uniformity, and shape-sphericity respectively)

Association of 18F-FDG PET/CT textural features with immunohistochemical characteristics in invasive ductal breast cancer.

OBJECTiVES: This study investigates whether textural features (TFs) extracted from 18F-FDG positron emission tomography/computed tomography (PET/CT) are associated with immunohistochemical characteristics (IHCs) of invasive ductal breast carcinoma (IDBC). MATERIALS AND METHODS: The relationship of TFs with IHCs [estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER-2), Ki-67 proliferation index, and histological grades] from solely excised primary tumors were evaluated for a more accurate assessment. Therefore patients with early-stage IDBC who underwent pre-operative 18F-FDG PET/CT scan for staging were included in this retrospective study. The clinical staging was performed according to the 8th edition of the American Joint Committee on Cancer. Maximum standardized uptake value (SUVmax) and 37TFs of the primary tumor were extracted from 18F-FDG PET/CT. Spearman's rank correlation test was used to evaluate the correlation between TFs and SUVmax. Receiver operating characteristic curves were generated to define the diagnostic performance of each parameter. Among these parameters, those with the highest diagnostic performance were included in the multivariate logistic regression model to identify the independent predictors of histopathological characteristics. RESULTS: A total of 124 patients were included. Histogram-uniformity, grey-level co-occurrence matrix (GLCM), GLCM-energy, and GLCM-homogeneity showed a strong negative correlation with SUVmax, while grey-level run-length matrix (GLRLM), GLRLM-SRHGE, grey-level zone length matrix (GLZLM), GLZLM-HGZE, GLRLM-HGRE, GLCM-entropy, GLCM-contrast, histogram-entropy, and GLCM-dissimilarity showed a strong positive correlation. Some of the TFs were independently associated with ER-negativity, PR-negativity, HER-2-positivity, and increased Ki-67 proliferation index (GLCM-contrast, GLZLM-GLNU, histogram-uniformity, and shape-sphericity respectively). While SUVmax had an independent association with high-grade and triple-negativity, GLZLM-SZLGE, a high-order TF that shows the distribution of the short homogeneous zones with low grey-levels, had an independent association with axillary lymph node metastasis. CONCLUSIONS: ER-negative, PR-negative, HER-2-positive, triple-negative, high-grade, highly proliferative, and high-stage tumors were found to be more glycolytic and metabolically heterogeneous. These findings suggest that the use of TFs in addition to SUVmax may improve the prognostic value of 18F-FDG PET/CT in IDBC, as certain TFs were independently associated with many IHCs and predicted axillary lymph node involvement.

Association of 18F-FDG PET/CT textural features with immunohistochemical characteristics in invasive ductal breast cancer. / Asociación de características de textura de la PET/TC con [18F]FDG con las características inmunohistoquímicas en el cáncer de mama ductal infiltrante.

OBJECTiVES: This study investigates whether textural features (TFs) extracted from F-18 FDG positron emission tomography/computed tomography (PET/CT) are associated with IHCs of invasive ductal breast carcinoma (IDBC). MATERIALS AND METHODS: The relationship of TFs with IHCs [estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER-2), Ki-67 proliferation index, and histological grades] from solely excised primary tumors were evaluated for a more accurate assessment. Therefore patients with early-stage IDBC who underwent pre-operative F-18 FDG PET/CT scan for staging were included in this retrospective study. The clinical staging was performed according to the 8th edition of the American Joint Committee on Cancer. Maximum standardized uptake value (SUVmax) and 37 TFs of the primary tumor were extracted from F-18 FDG PET/CT. Spearman's rank correlation test was used to evaluate the correlation between TFs and SUVmax. Receiver operating characteristic curves were generated to define the diagnostic performance of each parameter. Among these parameters, those with the highest diagnostic performance were included in the multivariate logistic regression model to identify the independent predictors of histopathological characteristics. RESULTS: A total of 124 patients were included. Histogram-uniformity, GLCM-energy, and GLCM-homogeneity showed a strong negative correlation with SUVmax, while GLRLM-SRHGE, GLZLM-HGZE, GLRLM-HGRE, GLCM-entropy, GLCM-contrast, histogram-entropy, and GLCM-dissimilarity showed a strong positive correlation. Some of the TFs were independently associated with ER-negativity, PR-negativity, HER-2-positivity, and increased Ki-67 proliferation index (GLCM-contrast, GLZLM-GLNU, histogram-uniformity, and shape-sphericity respectively). While SUVmax had an independent association with high-grade and triple-negativity, GLZLM-SZLGE, a high-order TF that shows the distribution of the short homogeneous zones with low grey-levels, had an independent association with axillary lymph node metastasis. CONCLUSIONS: ER-negative, PR-negative, HER-2-positive, triple-negative, high-grade, highly proliferative, and high-stage tumors were found to be more glycolytic and metabolically heterogeneous. These findings suggest that the use of TFs in addition to SUVmax may improve the prognostic value of F-18 FDG PET/CT in IDBC, as certain TFs were independently associated with many IHCs and predicted axillary lymph node involvement.

Comparison of 18F-FDG PET/CT and DW-MRI in assessment of neoadjuvant radiochemotherapy response in locally advanced rectal cancer patients. / Comparación de la PET/TC 18F-FDG y la DW-MRI en la evaluación de la respuesta a la radioquimioterapia neoadyuvante en pacientes con cáncer rectal localmente avanzado.

OBJECTIVE: Our aim is to evaluate if different metabolic parameters obtained by 18F-FDG PET/CT and diffusion weighted magnetic resonance imaging (DW-MRI) can aid in neoadjuvant radiochemotherapy (RCT) response assessment in locally advanced rectal cancer (LARC) patients. METHODS: Out of 20 LARC patients, who were planned to receive neoadjuvant RCT, 19 were included in this prospective study. Patients had 18F-FDG PET/CT and DW-MRI at initial staging, interim (2 weeks after onset of RCT) and after completion of RCT (post-therapy). Standardized uptake value (SUV) parameters (SUVmax, SUVmean, SUVpeak, SULpeak), metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) detected on PET images and apparent diffusion coefficient (ADC) values (for b=400 and b=1000s/mm2) obtained from DW-MRI were recorded. Postoperative tumor regression grade (TRG) was used as gold-standard, except for 2 patients who were under complete remission with non-operative management 19 months post-therapy and scored as responders. RESULTS: On interim PET/CT, no significant difference was found among PET parameters between responders and non-responders, whereas post-therapy SUVmax, SUVpeak, MTV, SULpeak, TLG (P=0.02, P=0.014, P=0.025, P=0.007, P=0.02, respectively) and initial MTV (P=0.034) were significantly lower in responders. ADC response index (RI) was higher in responders (interim P=0.026; post-therapy: P=0.018) and ROC analysis revealed that a threshold of ADC RI>41.6% for interim MRI and >44.6% for post-therapy MRI had sensitivity and specificity of 75.0% and 90.9%, respectively. CONCLUSIONS: While interim 18F-FDG PET/CT failed to predict therapy response during RCT, post-therapy PET could accurately differentiate responders. DW-MRI was found to be more promising in interim detection of RCT response.

Usefulness of 18F-Choline Positron Emission Tomography - Computed Tomography in the therapeutic management of patients with biochemical recurrence of prostate adenocarcinoma treated with brachytherapy. / Utilidad de la tomografía de emisión de positrones / tomografía computarizada con 18F-colina en el manejo terapéutico de pacientes con recidiva bioquímica de adenocarcinoma de próstata tratados con braquiterapia.

OBJECTIVE: The objective of the study was to evaluate the usefulness of 18F-choline PET/CT in biochemically recurrent prostate cancer patients treated with brachytherapy, as well as to assess the changes in therapeutic management derived from its outcome. MATERIAL AND METHODS: Retrospective study of 20 patients between 51 and 78 years old, with a history of prostate adenocarcinoma that had been treated with brachytherapy and presented biochemical recurrence (PSA 3.1-12 ng/ml) and staging tests (CT and bone scan) without alterations, were included. The findings visualized in the PET/CT scan with 18F-choline were correlated with the histopathology and/or the evolution of the PSA after therapy. RESULTS: 18F-choline PET/CT scan only detected local recurrence in 15 patients. Local and regional recurrences were seen in 4 patients, and 1 patient presented local and bone recurrence. Local recurrence detected in PET was confirmed by anatomopathological studies in 85% of the cases. In one patient, these findings (PET scan) turned out to be prostatitis, and it could not be confirmed in another patient. Of the cases with local and regional recurrence, local recurrence was histologically confirmed in 3 out of 4 patients. 18F-choline PET/CT changed the therapeutic management in 25% of the patients, discarding the initially planned salvage surgery in 3 cases, 1 radiotherapy and 1 brachytherapy. CONCLUSION: 18F-choline PET/CT could be a useful technique in the group of patients with biochemical recurrence after brachytherapy, providing locoregional and distant involvement findings which had not been detected with conventional imaging tests, thus determining a more adequate therapeutic management.

Intraductal papillary neoplasm of the bile duct: Radiologic findings in a new disease. / Neoplasia papilar intraductal de la vía biliar: radiología en una nueva entidad.

Intraductal papillary neoplasm of the biliary tract (B-IPN) is a scarcely known entity in our daily practice due to its low prevalence. Until its new definition in the fourth edition of the WHO classification of the digestive tract tumors of 2010 the disease was grouped under a heterogeneous and imprecise terminology. In addition, in recent years there has been progress in the knowledge of its etiopathogenesis, its natural history and its findings in image. The purpose of this paper is to review these data underlining the radiological findings of the disease and its differential diagnosis.

Contribution of 11C-Choline PET/CT in prostate carcinoma biochemical relapse with serum PSA level below 1 ng/ml. / Aportación de la PET/TC con 11C-colina en la recidiva bioquímica del cáncer de próstata con antígeno específico prostático sérico inferior a 1 ng/ml.

OBJECTIVE: 11C-choline PET/CT has demonstrated good results in the restaging of prostate cancer (PCa) with high serum prostate specific antigen (PSA), but its use in patients with low serum PSA is controversial. Our aim was to evaluate the contribution of 11C-choline PET/CT in patients with PCa, biochemical relapse and PSA <1 ng/ml. MATERIAL AND METHOD: Fifty consecutive patients (mean age: 65.9±5.6 years) with biochemical relapse of PCa and serum PSA <1ng/ml were evaluated retrospectively. PET/CT was performed 20min after intravenous administration of 555-740 MBq of 11C-choline. Minimum follow up time was 30 months. RESULTS: Twenty-one out of 50 patients (42%) had an abnormal 11C-choline PET/CT. In 7 out of 21 patients (14%) tumor was confirmed (4 in prostatic bed, 4 in pelvic lymph nodes, 2 in mediastinal lymph nodes and one synchronous sigmoid carcinoma), and in all cases the initial therapeutic planning was modified. In 2 patients (4%) subsequent tests diagnosed a benign disease (one sarcoidosis, one tuberculosis sequelae) and in 3 patients (6%) they ruled out pathology. The other 9 patients (18%) had no further assessment (7 mediastinal and 4 pelvic lymph nodes). Twenty-nine out of 50 patients (58%) had a normal PET/CT. At 30 months, follow up recurrence was confirmed only in 2 of these patients. CONCLUSIONS: 11C-choline PET/CT proved its usefulness in demonstrating tumor in 14% of patients with BR of PCa and serum PSA <1ng/ml, with therapeutic implications. In 4% of patients a benign condition was detected. A normal 11C-choline PET/CT was associated with a very low rate of recurrence at 30 months.

Diferencias y controversias entre el reporte de patología y la interpretación clínica en patología tiroidea. II PARTE: Aspectos patológicos y métodos diagnósticos con impacto terapéutico / Thyroid diseases: Differences and controversies between the pathology report and clinical interpretation. PART II: Pathological aspects and diagnostic methods with therapeutic impact

Resumen Como revisamos en la primera parte1 hay algunos conceptos que deben ser considerados para el adecuado manejo médico por parte del equipo clínico que recibe el reporte de patología, de esta misma manera existen aspectos por parte del patólogo que este debe conocer, los cuales tienen impacto terapéutico. En esta segunda parte queremos revisar algunos conceptos que son de importancia por parte del patólogo que aplican directamente sobre la interpretación del clínico, como: procesamiento macroscópico; estudio de la citología por aspiración con aguja fina (FNA) vs. biopsia trucut, utilidad de la biopsia por congelación y de la inmunohistoquímica, así como los métodos e imágenes diagnósticas.

Abstract As was reviewed in the first part, there are some concepts that should be considered for the appropriate medical management by the medical team that receives the pathology report. Similarly, there are some aspects that the pathologist should know, such as those that can have therapeutic impact. In this second part, a short review is presented on some of the concepts that are of importance to the pathologist that apply directly to the interpretation by the clinician, such as the macroscopic processing, the cytology study of the fine-needle aspirate (FNA) vs. "tru-cut" biopsy, the usefulness of the frozen biopsy, and immunohistochemistry, as well as diagnostic methods and diagnostic images.

Utility of 18 fludeoxyglucose in preoperative positon-emission tomography-computed tomography (PET-CT) in the early diagnosis of exocrine pancreatic cancer: A study of 139 resected cases. / Utilidad de la 18-fluorodeoxiglucosa en la tomografía por emisión de positrones-tomografía computarizada (PET-TC) preoperatoria en el diagnóstico precoz del cáncer de páncreas exocrino: estudio en 139 casos resecados.

INTRODUCTION: In pancreatic ductal adenocarcinoma (PDA), surgical resection is the only curative treatment, but due to its late clinical presentation only 15-25% patients are candidates for curative resection. The aim of this prospective, single-center study is to determine the diagnostic utility of preoperative PET-CT for early detection of PDA and early panIN lesions. METHODS: We studied the histopathological features of PDA and different panIN lesions in 139 surgical samples from patients undergoing pancreatic resection (from 2010-2014), comparing these results with preoperative PET-CT and MDCT study. For tumor diagnosis in PET-CT maximum standard SUV 2.5 was used. Pancreatic baseline SUVmax is the maximum uptake of the radiotracer 18-2FDG on the ROI curve determined for the area of the normal pancreas after pathological reassessment with areas not affected by tumours or preneoplastic lesions. Tumour Uptake Index is the ratio between the tumour SUVmax and pancreatic baseline SUVmax. RESULTS: Using an standard maximum SUV value of 2.5, PET-CT sensitivity was 77.7% (108 of the 139 cases) against 75.5% (105 of the 139 cases) of MDCT. But when we combined this value with maximum SUV of normal pancreatic tissue from each patient, PET-CT sensitivity improved its value to 94.9%. CONCLUSION: A combination of studies of PET-CT in tumor and non-tumor tissue of each patient might be a very useful diagnostic tool not only for preoperative diagnosis of PDA, but also for early panIN lesions.

Adrenal tuberculosis masquerading as disseminated malignancy: A pitfall of (18)F-FDG PET/CT Imaging.

Non-invasive characterization of adrenal lesions is a commonly encountered diagnostic challenge. Characteristic clinical and correlative imaging findings may assist in only arriving at a probable diagnosis. Currently, (18)F-FDG PET/CT is considered to provide the most comprehensive imaging information. We here present a case of bilateral adrenal tuberculosis that highlights the need for caution during the interpretation of (18)F-FDG PET/CT and also the need to suggest histopathological correlation.

(18)F-FDG PET/CT versus bone scintigraphy in the follow-up of gastric cancer.

A 53-year-old patient underwent a positron emission tomography/computed tomography with 2-fluoro-2-deoxy-d-glucose ((18)F-FDG PET/CT) in the suspicious of gastric tumor recurrence (mediastinal and abdominal lymph nodes). PET/CT identified only an area of (18)F-FDGuptake in the twelfth thoracic vertebrae. Unexpectedly, a bone scintigraphy revealed many "hot" spots changing the diagnosis (single metastasis versus plurimetastatic disease) and impacting on patient's management.

(11)C-choline PET/CT and multiparametric MRI in patients with biochemical relapse of prostate cancer.

CLINIC PROBLEM AND CASE SERIES: To assess the diagnostic usefulness of (11)C-choline PET/CT vs. multi-parametric MRI in the prostate cancer relapse. A retrospective study of 21 patients with prostate cancer treated initially with surgery (n=12), radiotherapy (n=9). PSA levels were increased (post-surgery: .3-3.6 ng/ml; post-radiotherapy: 2.4-8.8 ng/ml). In an interval of time of 15 days all patients were underwent to: whole-body-dual-modality PET-CT carried out early after (11)C-choline (296 ± 29 MBq) injection, and multiparametric prostate MRI with paramagnetic intravenous contrast (using anatomical imaging sequences, diffusion-weighted imaging and dynamic contrast-enhanced imaging). On the basis of our results, all patients were underwent to directed diagnosis and/or clinical, analytic and imaging follow-up. In 15 patients (71.4%) both procedures showed concordant results: 4 negative and 11 positive cases [7 local recurrences, 3 isolated pelvic lymph nodes (2 infracentimetric), 1 local relapse and only one M1 bone metastases]. The results were discordant in 6 patients (28.6%): 3 local relapses in MRI with no PET significance, 1 local relapse in PET with no MRI significance. 2 bone metastases were identified with PET (out of the field-of-view of MRI). COMMENT: (11)C-choline PET/CT and multi-parametric MRI play a complementary role in the detection of local relapse in prostate cancer patients, with similar sensitivity for the detection of lymph involvement. Whole-body 11C-choline PET/CT technique is also useful for bone staging.

[Extension study and evaluation of the therapeutic response in a patient with metastatic lung adenocarcinoma using sequential study with ¹8F-FDG PET-CT and ¹8F-fluoride PET-CT]. / Estudio de extensión y valoración de la respuesta terapéutica en un paciente con adenocarcinoma pulmonar metastásico mediante estudio secuencial con (18)F-FDG PET-TC y (18)F-fluoruro PET-TC.

We report a case of a patient with lung adenocarcinoma and bone and extraosseus metastases studied with (18)F-FDG PET-CT, (99m)Tc-HMDP and (18)F-fluoride PET-CT. It assesses the usefulness of (18)F-FDG PET-CT for initial staging of the disease and monitoring response to therapy. For the study of the sclerotic bone metastases it shows the superiority of 99mTc-HMDP bone scintigraphy and (18)F-fluoride PET-CT over (18)F-FDG PET-CT, and (18)F-fluoride PET-CT over bone scintigraphy. It also shows the usefulness of (18)F-fluoride PET-CT for monitoring the bone metastases.

Diagnostic imaging in dermatology: utility of PET-CT in cutaneous melanoma.

Malignant melanoma accounts for 5% of all malignant skin tumors and its incidence is increasing. In the natural course of melanoma, tumors grow locally and can spread via the lymph system or the blood. Because survival is directly related to the stage of the disease at diagnosis, early detection (secondary prevention) has an impact on prognosis. Positron emission tomography (PET) is a nuclear medicine technique that generates images using molecules labeled with positron-emitting isotopes. The most widely used molecule is fluorodeoxyglucose (FDG). Because of the elevated glycolytic rate in tumor cells, which results in increased FDG uptake, greater quantities of FDG become trapped in tumor cells, enabling external detection. Today, most PET scanners are multimodal PET-computed tomography (CT) scanners, which provide more detailed information by combining morphological information with functional PET findings. The possible utility of PET-CT in patients with malignant melanoma is a subject of debate. Various questions have been raised: when the scan should be performed, whether PET-CT has advantages over conventional diagnostic methods, and whether PET-CT provides a real benefit to patients. In this review of the literature, we will analyze each of these questions.

The role of positron emission tomography/computed tomography imaging with radiolabeled choline analogues in prostate cancer.

INTRODUCTION: prostate cancer is the most frequent solid malignant tumor in Western Countries. Positron emission tomography/x-ray computed tomography imaging with radiolabeled choline analogues is a useful tool for restaging prostate cancer in patients with rising prostate-specific antigen after radical treatment (in whom conventional imaging techniques have important limitations) as well as in the initial assessment of a selected group of prostate cancer patients. For this reason a literature review is necessary in order to evaluate the usefulness of this imaging test for the diagnosis and treatment of prostate cancer. EVIDENCE ACQUISITION: a MEDLINE (PubMed way) literature search was performed using the search parameters: «Prostate cancer¼ and «Choline-PET/CT¼. Other search terms were «Biochemical failure¼ and/or «Staging¼ and/or «PSA kinetics¼. English and Spanish papers were selected; original articles, reviews, systematic reviews and clinical guidelines were included. CONCLUSIONS: according to available data, radiolabeled choline analogues plays an important role in the management of prostate cancer, especially in biochemical relapse because technique accuracy is properly correlated with prostate-specific antigen values and kinetics. Although is an emerging diagnostic technique useful in treatment planning of prostate cancer, final recommendations have not been submitted.