Relación entre el índice de Breslow y el resultado de la PET-TC en la estadificación inicial del melanoma cutáneo: ¿es posible establecer un punto de corte? / Breslow thickness and 18F-FDG PET-CT result in initial staging of cutaneous melanoma: Can a cut-off point be established?

Objetivo. Establecer un punto de corte del índice de Breslow (IB) para la indicación del estudio PET-TC en la estadificación del melanoma cutáneo en estadios iniciales y evaluar su valor pronóstico. Material y métodos. Análisis retrospectivo de 347 estudios PET-TC con 18F-FDG con diagnóstico de melanoma, siendo 108 de estadificación. Excluimos 31 obteniendo una muestra final de 77 pacientes. Para establecer el punto de corte óptimo llevamos a cabo un análisis de la curva ROC. Para evaluar el valor pronóstico se realizó un análisis de supervivencia registrando la muerte atribuible al melanoma. Resultados. De los 77 pacientes, 47 eran varones (61,04%) y 11 (14,29%) presentaron un resultado PET-TC positivo. La edad media fue 65,17 ± 15,00 años. La mediana del IB en el grupo con PET-TC negativo fue 2,75 mm (IQR 1,83-4,50) y en el grupo con resultado positivo 6,25 mm (IQR 5,40-7,50) (p = 0,0013). El análisis de la curva ROC (AUC 0,804, SE 0,054) dio como óptimo un punto de corte de 5 mm: sensibilidad 90,91%, especificidad 78,79%, VPN 98,1%, VPP 41,7%, OR diagnóstica 37,1 y exactitud diagnóstica 80,52%. El seguimiento medio fue de 18,66 ± 14,35 meses, observándose 3,77% muertes en el grupo con IB < 5 mm y 29,17% en el grupo con IB ≥ 5 mm. Las curvas de supervivencia entre ambos grupos fueron significativamente diferentes (p = 0,0013). Conclusiones. Un punto de corte de IB de 5 mm discrimina de manera adecuada a aquellos pacientes con PET-TC positiva de aquellos con resultado negativo en estadios precoces del melanoma cutáneo, por lo que podría incluirse en la estadificación inicial de este subgrupo de pacientes (AU)

Aim. To establish a Breslow Thickness (BT) cut-off point for indication of PET-CT of cutaneous melanoma in early stages and evaluate its prognostic value. Material and methods. Retrospective analysis of 347 PET-CT studies with diagnosis of melanoma, of which 108 were performed for initial staging. Thirty-one patients were excluded, and a final sample of 77 patients remained. A ROC curve analysis was performed to establish an optimal cut-off point. A survival analysis was performed, considering death assignable to melanoma as the main event, for the evaluation of its prognostic value. Results. Forty-seven (61.04%) of all 77 patients selected were men, and 11 (14.29%) had a positive PET-CT result. Mean age was 65.17 ± 15.00 years. The median BT in patients with a negative PET-CT result was 2.75 mm (IQR 1.83-4.50) and in the positive group 6.25 mm (IQR 5.40-7.50) (P=.0013). In the ROC curve analysis (AUC 0.804, SE 0.054), an optimal value of 5 mm BT with the following values was obtained: sensitivity 90.91%, specificity 78.79%, negative predictive value (NPV) 98.1%, positive predictive value (PPV) 41.7%, diagnostic OR 37.1, and accuracy 80.52%. Mean follow-up was 18.66 ± 14,35 months, detecting 2/53 (3.77%) deaths in the BT < 5 mm group, and 7/24 (29.17%) in the BT≥5 mm group. Survival curves between both groups were significantly different (P=.0013). Conclusions. A 5 mm cut-off point correctly distinguishes those patients with positive PET-CT from those with negative results in the early stages of cutaneous melanoma; therefore it could be included in initial staging of this subgroup of patients (AU)

Endocarditis infecciosa detectada mediante PET-TC con 18F-FDG en un paciente con bacteriemia por gram positivo de origen desconocido / Infective endocarditis detected by 18F-FDG PET-CT in a patient with gram-positive bacteraemia of unknown origin

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Breslow thickness and (18)F-FDG PET-CT result in initial staging of cutaneous melanoma: Can a cut-off point be established?

AIM: To establish a Breslow Thickness (BT) cut-off point for indication of PET-CT of cutaneous melanoma in early stages and evaluate its prognostic value. MATERIAL AND METHODS: Retrospective analysis of 347 PET-CT studies with diagnosis of melanoma, of which 108 were performed for initial staging. Thirty-one patients were excluded, and a final sample of 77 patients remained. A ROC curve analysis was performed to establish an optimal cut-off point. A survival analysis was performed, considering death assignable to melanoma as the main event, for the evaluation of its prognostic value. RESULTS: Forty-seven (61.04%) of all 77 patients selected were men, and 11 (14.29%) had a positive PET-CT result. Mean age was 65.17±15.00 years. The median BT in patients with a negative PET-CT result was 2.75 mm (IQR 1.83-4.50) and in the positive group 6.25 mm (IQR 5.40-7.50) (P=.0013). In the ROC curve analysis (AUC 0.804, SE 0.054), an optimal value of 5 mm BT with the following values was obtained: sensitivity 90.91%, specificity 78.79%, negative predictive value (NPV) 98.1%, positive predictive value (PPV) 41.7%, diagnostic OR 37.1, and accuracy 80.52%. Mean follow-up was 18.66±14,35 months, detecting 2/53 (3.77%) deaths in the BT<5 mm group, and 7/24 (29.17%) in the BT≥5 mm group. Survival curves between both groups were significantly different (P=.0013). CONCLUSIONS: A 5 mm cut-off point correctly distinguishes those patients with positive PET-CT from those with negative results in the early stages of cutaneous melanoma; therefore it could be included in initial staging of this subgroup of patients.

Significación de captaciones incidentales en colon en estudios 18F-FDG PET-TAC en pacientes sin tumor colorrectal conocido. Valoración del impacto en el manejo del paciente / Clinical relevance of incidental finding of focal uptakes in the colon during 18F-FDG PET/CT studies in oncology patients without known colorectal carcinoma and evaluation of the impact on management

Objetivos. Valorar la significación y el impacto de acumulaciones de FDG en el colon en pacientes con tumores no colorrectales. Material y métodos. Se revisaron retrospectivamente 2.220 estudios PET-TAC realizados de manera consecutiva en el Servicio de Medicina Nuclear de nuestro hospital del 2 de diciembre de 2008 al 31 de mayo de 2010. Se incluyeron aquellos pacientes en los que se describían captaciones focales de FDG a nivel colorrectal y no explicables por la historia clínica. Se excluyeron pacientes diagnosticados previamente de carcinoma colorrectal. Cumplieron el criterio de inclusión 86 pacientes (57 hombres, media de edad de 63,4 años, rango 46-85). Se estableció como prueba de referencia la colonoscopia con toma de biopsia. Se valoró el impacto de estos hallazgos en la actitud diagnóstico-terapéutica de estos pacientes. Resultados. En 54 de los 86 pacientes se realizó correlación colonoscópica, en los 32 restantes no se había realizado dicha exploración hasta la fecha. De los 54 en los que se realizó colonoscopia se tomó biopsia en 43 lesiones. Se detectó patología colónica en 49 pacientes, con un total de 54 focos incidentales de FDG, siendo estas patologías: 10 cánceres colorrectales primarios insospechados, tres metástasis, 27 pólipos adenomatosos con diferentes grados de displasia y 14 procesos inflamatorios. En los 5 pacientes restantes la colonoscopia fue normal (9%). La PET-TAC modificó la actitud diagnóstico-terapéutica en la mayoría de pacientes (49/ 54, 91%). Conclusiones. Estos resultados constatan la necesidad de confirmar mediante colonoscopia y biopsia las captaciones focales colorrectales de FDG en PET-TAC. Esta estrategia permite detectar y tratar precozmente lesiones malignas y premalignas(AU)

Aims. To assess the significance and the impact of focal FDG uptake in the colon in oncology patients without known colorectal carcinoma. Materials and methods. A retrospective study was undertaken on 2,220 18F-FDG PET/CT studies carried out consecutively in the Nuclear Medicine Department in our hospital from 2 December 2008 to 31 May 2010. Inclusion criteria were patients with abnormal 18F-FDG uptake in colorectal area that could not be explained (or not previously known) by their clinical histories. Patients previously diagnosed with colorectal carcinoma were excluded. A total of 86 patients (57 male, average age 63.4, range 46-85) were finally included. Colonoscopy with biopsy was established as a reference test. The impact of these findings on the diagnostic-therapeutic management in these patients was evaluated. Results. A colonoscopy was performed in 54 of the 86 patients, this examination not having been done up-to-date in the remaining 32 patients. Biopsy was obtained in 43 lesions of the 54 patient in whom a colonoscopy was performed. Colon disease was detected in 49 of these 54 patients, obtaining 54 FDG incidental foci which corresponded to 10 previously unsuspected primary colorectal carcinoma, 3 metastases, 27 adenomatous polyps with different degrees of dysplasia and 14 inflammatory processes. In the remaining 5 patients, the colonoscopy was normal. PET/CT modified the diagnostic and treatment management in most of the patients (49/54, that is 91%). Conclusions. These results confirm the need to determine the cause of abnormal 18F-FDG colorectal uptakes in the PET/CT studies by using colonoscopy and biopsy. This approach allows for the detection and early treatment of malignant and premalignant lesions(AU)

Clinical relevance of incidental finding of focal uptakes in the colon during 18F-FDG PET/CT studies in oncology patients without known colorectal carcinoma and evaluation of the impact on management.

AIMS: To assess the significance and the impact of focal FDG uptake in the colon in oncology patients without known colorectal carcinoma. MATERIALS AND METHODS: A retrospective study was undertaken on 2,220 (18)F-FDG PET/CT studies carried out consecutively in the Nuclear Medicine Department in our hospital from 2 December 2008 to 31 May 2010. Inclusion criteria were patients with abnormal (18)F-FDG uptake in colorectal area that could not be explained (or not previously known) by their clinical histories. Patients previously diagnosed with colorectal carcinoma were excluded. A total of 86 patients (57 male, average age 63.4, range 46-85) were finally included. Colonoscopy with biopsy was established as a reference test. The impact of these findings on the diagnostic-therapeutic management in these patients was evaluated. RESULTS: A colonoscopy was performed in 54 of the 86 patients, this examination not having been done up-to-date in the remaining 32 patients. Biopsy was obtained in 43 lesions of the 54 patient in whom a colonoscopy was performed. Colon disease was detected in 49 of these 54 patients, obtaining 54 FDG incidental foci which corresponded to 10 previously unsuspected primary colorectal carcinoma, 3 metastases, 27 adenomatous polyps with different degrees of dysplasia and 14 inflammatory processes. In the remaining 5 patients, the colonoscopy was normal. PET/CT modified the diagnostic and treatment management in most of the patients (49/54, that is 91%). CONCLUSIONS: These results confirm the need to determine the cause of abnormal (18)F-FDG colorectal uptakes in the PET/CT studies by using colonoscopy and biopsy. This approach allows for the detection and early treatment of malignant and premalignant lesions.

Pancreatic involvement detected with 18F-FDG PET/CT in disseminated sarcoidosis

La sarcoidosis es una enfermedad granulomatosa de etiología desconocida. Puede simular malignidad y puede afectar a múltiples órganos, con una evolución clínica variable. La afectación del páncreas es excepcional. Se presenta el caso de una mujer de 78 años con sarcoidosis sistémica en la que la PET-TAC con 18F-FDG mostró una lesión pancreática y múltiples lesiones hipermetabólicas ganglionares (torácicas y extratorácicas) y viscerales. La captación patológica de 18F-FDG en páncreas se limitaba a la cola. Un segundo estudio PET-TAC con 18F-FDG realizado 4 meses y tres semanas después del primer estudio, tras haber aplicado terapia corticoidea durante 3,5 meses, evidenció una regresión parcial de la enfermedad, con una captación patológica persistente de 18F-FDG en la lesión pancreática(AU)

Sarcoidosis is a granulomatous disease of unknown etiology. It may mimic malignancy and may affect multiple organs, with a variable clinical course. Pancreatic involvement is very rare. We present the case of a 78-year-old woman with systemic sarcoidosis whose 18F-FDG PET/CT scan showed a pancreatic lesion and multiple lymphatic (thoracic and non-thoracic) and visceral lesions. The abnormal 18F-FDG uptake in the pancreas was limited to the tail. A second 18F-FDG PET/CT study performed 4 months and 3 weeks after the first PET/CT, following corticosteroid therapy during three and a half months, evidenced partial regression of the disease, with persistent 18F-FDG pathological uptake in the pancreatic lesion(AU)

Pancreatic involvement detected with (18)F-FDG PET/CT in disseminated sarcoidosis.

La sarcoidosis is a granulomatous disease of unknown etiology. It may mimic malignancy and may affect multiple organs, with a variable clinical course. Pancreatic involvement is very rare. We present the case of a 78-year-old woman with systemic sarcoidosis whose (18)F-FDG PET/CT scan showed a pancreatic lesion and multiple lymphatic (thoracic and non-thoracic) and visceral lesions. The abnormal (18)F-FDG uptake in the pancreas was limited to the tail. A second (18)F-FDG PET/CT study performed 4 months and 3 weeks after the first PET/CT, following corticosteroid therapy during three and a half months, evidenced partial regression of the disease, with persistent (18)F-FDG pathological uptake in the pancreatic lesion.

Calidad diagnóstica y repercusión del empleo de contrastes en los estudios de tomografía computarizada de exploraciones con tomografía por emisión de positrones en combinación con tomografía computarizada / The impact on diagnostic quality of using contrast media in PET-CT studies

Objetivo. Valorar la repercusión del uso de contrastes radiológicos en las exploraciones de tomografía por emisión de positrones en combinación con tomografía computarizada (PET-TC) utilizados en nuestro centro. Material y métodos. Los estudios se realizaron en un equipo PET-TC con una TC multidetector de 6 detectores. La población estudiada fueron pacientes oncológicos. Las indicaciones para realizar estos estudios fueron las incluidas en la ficha técnica de la 18F-2-fluoro-2-desoxi-D-glucosa. Se realizó un estudio retrospectivo observacional con el fin de valorar la calidad de los estudios PET-TC realizados con contrastes radiológicos y la presencia de artefactos generados por estos contrastes. Resultados. Entre febrero y junio de 2009 se han realizado 612 exploraciones PET-TC. Trescientas sesenta y nueve fueron en varones y 243 en mujeres. Se administró contraste iodado intravenoso en el 48% de los pacientes y oral en el 18%. La calidad diagnóstica se valoró como alta en el 93,5% de los estudios, como media en el 4,3% y como baja en el 2,2%. De las TC realizadas con contraste intravenoso se identificaron artefactos por contraste en el 8%, y en el 1,4% ocasionaron dudas diagnósticas en la PET. El contraste oral no produjo problemas diagnósticos en ninguna ocasión. Conclusiones. En el análisis de nuestros estudios hemos observado que el uso de contrastes radiológicos en las exploraciones PET-TC no deteriora la calidad diagnóstica ni altera el flujo de trabajo. Si a esto se añade que una TC de alta calidad diagnóstica puede mejorar la capacidad de detección de la PET-TC nos parece adecuado incluirla en los protocolos de exploración (AU)

Objective. To evaluate the impact of using radiologic contrast media on the quality of PET-CT studies at our center. Material and methods. This is a retrospective observational study to evaluate the quality of the PET-CT studies carried out with radiologic contrast media and the presence of artifacts due to these contrast agents. Oncologic patients in whom PET was indicated according to the manufacturer's specifications for FDG (18F-2-fluoro-2-deoxy-D-glucose) underwent PET-CT study on a PET-CT system with a six-detector-row CT scanner. Results. Between February 2009 and June 2009, we performed 612 PET-CT examinations in 369 male patients and 243 female patients. Iodinated contrast media were administered intravenously in 48% and orally in 18%. Diagnostic quality was considered high in 93.5% of the studies, intermediate in 4.3%, and low in 2.2%. In the CT studies performed using intravenous contrast agents, artifacts were identified in 8% and resulted in diagnostic uncertainty in the PET study in 1.4%. We found no diagnostic problems caused by oral contrast agents in any case. Conclusions. The use of radiologic contrast agents in PET-CT studies does not negatively affect diagnostic quality or workflow. Given that we can improve the ability of PET-CT to detect lesions by enhancing the diagnostic quality of the CT study, we consider it appropriate to include the administration of contrast agents in protocols for PET-CT studies (AU)

[The impact on diagnostic quality of using contrast media in PET-CT studies]. / Calidad diagnóstica y repercusión del empleo de contrastes en los estudios de tomografía computarizada de exploraciones con tomografía por emisión de positrones en combinación con tomografía computarizada.

OBJECTIVE: To evaluate the impact of using radiologic contrast media on the quality of PET-CT studies at our center. MATERIAL AND METHODS: This is a retrospective observational study to evaluate the quality of the PET-CT studies carried out with radiologic contrast media and the presence of artifacts due to these contrast agents. Oncologic patients in whom PET was indicated according to the manufacturer's specifications for FDG ((18)F-2-fluoro-2-deoxy-D-glucose) underwent PET-CT study on a PET-CT system with a six-detector-row CT scanner. RESULTS: Between February 2009 and June 2009, we performed 612 PET-CT examinations in 369 male patients and 243 female patients. Iodinated contrast media were administered intravenously in 48% and orally in 18%. Diagnostic quality was considered high in 93.5% of the studies, intermediate in 4.3%, and low in 2.2%. In the CT studies performed using intravenous contrast agents, artifacts were identified in 8% and resulted in diagnostic uncertainty in the PET study in 1.4%. We found no diagnostic problems caused by oral contrast agents in any case. CONCLUSIONS: The use of radiologic contrast agents in PET-CT studies does not negatively affect diagnostic quality or workflow. Given that we can improve the ability of PET-CT to detect lesions by enhancing the diagnostic quality of the CT study, we consider it appropriate to include the administration of contrast agents in protocols for PET-CT studies.

[SPECT-CT in sentinel node detection in patients with melanoma]. / SPECT-TAC en la localización del ganglio centinela en pacientes con melanoma.

INTRODUCTION: The prognosis of patients with cutaneous melanoma is greatly influenced by the presence of lymph node metastases. One of the most innovative and fascinating concepts to emerge in the field of oncology in recent years is the use of sentinel lymph node biopsy (SLNB). AIM: The aim of this study was to determine what SPECT-CT images contribute to the search for sentinel nodes in patients with melanoma. METHODS: From March 2007 to October 2008, 18 patients were examined for sentinel nodes using dynamic scintigraphy, planar images, and SPECT-CT in the Nuclear Medicine Department of San Carlos University Hospital. The group contained 10 women and 8 men, age range 14-83 years, mean age 57 years (57+/-20.1). RESULTS: The sentinel node was located by conventional imaging techniques (dynamic scintigraphy and planar images) in 16 of 18 patients (88.88%). SPECT-CT identified the sentinel node in 18 of 18 patients (100%) and detected clinically relevant findings in 6 of 18 patients (33.33%) CONCLUSIONS: SPECT-CT imaging contributed clinically relevant information on sentinel nodes of melanoma, which is particularly important in patients with melanoma of the trunk or head and neck.

SPECT-TAC en la localización del ganglio centinela en pacientes con melanoma / SPECT-CT in sentinel node detection in patients with melanoma

IntroducciónEl pronóstico de los pacientes con melanoma está fuertemente influenciado por la presencia de afectación tumoral ganglionar. Uno de los conceptos más innovadores y fascinantes que ha emergido en el campo de la oncología en los últimos años es la biopsia selectiva del ganglio centinela.ObjetivoValorar la aportación que las imágenes de SPECT (single photon emission computed tomography ‘tomografía computarizada por emisión de fotón simple’) y tomografía axial computarizada (TAC) (SPECT-TAC) han realizado a la localización del ganglio centinela en pacientes con melanoma.Material y métodosEntre marzo de 2007 y octubre de 2008, 18 pacientes diagnosticados de melanoma fueron estudiados mediante gammagrafía dinámica, estudio planar y SPECT-TAC en el Servicio de Medicina Nuclear del Hospital Clínico San Carlos. Se trataba de 10 mujeres y 8 varones con una edad comprendida entre los 14 y los 83 años, con una edad media de 57 años (57±20,1).ResultadosEl ganglio centinela fue localizado mediante las técnicas convencionales (estudio dinámico e imágenes planares) en 16 de los 18 pacientes incluidos en el estudio, alcanzando una tasa de detección del 88,8%. El estudio SPECT-TAC logró localizar el ganglio centinela en los 18 pacientes alcanzando una tasa de detección del 100%. Además, aportó información relevante en 6 de los 18 pacientes (33%).ConclusionesLa SPECT-TAC aporta información clínicamente relevante en la localización del ganglio centinela en pacientes con melanoma. Esta aportación resulta de mayor trascendencia en pacientes con melanoma de cabeza y cuello, y en pacientes con melanoma localizado en el tronco(AU)

IntroductionThe prognosis of patients with cutaneous melanoma is greatly influenced by the presence of lymph node metastases. One of the most innovative and fascinating concepts to emerge in the field of oncology in recent years is the use of sentinel lymph node biopsy (SLNB).AimThe aim of this study was to determine what SPECT-CT images contribute to the search for sentinel nodes in patients with melanoma.MethodsFrom March 2007 to October 2008, 18 patients were examined for sentinel nodes using dynamic scintigraphy, planar images, and SPECT-CT in the Nuclear Medicine Department of San Carlos University Hospital. The group contained 10 women and 8 men, age range 14–83 years, mean age 57 years (57±20.1).ResultsThe sentinel node was located by conventional imaging techniques (dynamic scintigraphy and planar images) in 16 of 18 patients (88.88%). SPECT-CT identified the sentinel node in 18 of 18 patients (100%) and detected clinically relevant findings in 6 of 18 patients (33.33%)ConclusionsSPECT-CT imaging contributed clinically relevant information on sentinel nodes of melanoma, which is particularly important in patients with melanoma of the trunk or head and neck(AU)

[SPECT-CT: a new tool for localisation of sentinel lymph nodes in breast cancer patients]. / SPECT-TAC: una nueva herramienta para la localización del ganglio centinela en pacientes con cáncer de mama.

INTRODUCTION: Sentinel lymph node biopsy has become a widely accepted procedure for axillary lymph node staging in patients with breast cancer. AIM: The aim of this study was to determine the advantages of using SPECT-CT instead of planar scintigraphy in the presurgical localisation of sentinel lymph nodes. METHODS: We prospectively included 25 consecutive patients with breast cancer who were admitted to our department for SLN localisation. Patients were divided into two groups, depending on whether neoadjuvant chemotherapy had been received (B, n = 6) or not (A, n = 19). Four doses (1.0 mCi each) of 99mTc-nanocolloid were injected intradermallly in all patients, and SPECT-CT and planar images were acquired. All patients underwent surgery and SLN localisation with a hand-held gamma probe. Any axillary "hot spots" were resected. The kappa index (ki) was calculated using surgical findings as the gold standard. RESULTS: In group A, the SLN was correctly detected in 17/19 patients (89.5 %) with SPECT-CT and in 12/19 (63.2 %) with planar images. The correlation between SPECT-CT and surgical findings (ki 0.91) was better than between planar images and surgical findings (ki 0.57). In group B, the results of SPECT-CT and planar images were identical, with accurate localisation of the SLN in 5/6 patients (ki 0.76). CONCLUSIONS: The results of this study suggest that SPECT-CT may be useful for locating the SLN in breast cancer patients, as it provides accurate localization of the SLN with useful anatomical information. This may allow the surgeon to search exclusively for SLN viewed on SPECT-CT, and avoid false negative and false positive results.

SPECT-TAC: una nueva herramienta para la localización del ganglio centinela en pacientes con cáncer de mama / SPECT-CT: a new tool for localisation of sentinel lymph nodes in breast cancer patients

Introducción. La biopsia selectiva del ganglio centinela es una herramienta que ha demostrado ser eficaz en la estadificación linfática, evitando realizar linfadenectomías a pacientes que no van a beneficiarse de ellas. Objetivo. Determinar las ventajas de la SPECT-TAC frente a la gammagrafía convencional en la localización prequirúrgica del ganglio centinela. Material y métodos. Se trata de un estudio prospectivo con 25 pacientes divididas en dos grupos, según hubiesen recibido o no quimioterapia neoadyuvante (grupo A, n = 19 sin quimioterapia previa; grupo B, n = 6 con quimioterapia), a las que se les realizó la gammagrafía planar convencional y un estudio con un equipo híbrido SPECT-TAC de baja dosis. Se realizó la localización intraoperatoria con sonda portátil resecando todos los depósitos existentes en la axila. Resultados. La SPECT-TAC determinó correctamente el número y localización de los ganglios en 17 de 19 pacientes del grupo A, frente a 12 de 19 pacientes en las que lo hizo la gammagrafía. La concordancia de la SPECT-TAC con los hallazgos de la cirugía fue muy buena (índice kappa 0,91), mientras que la gammagrafía presentó una concordancia moderada (índice kappa 0,57). Conclusiones. La SPECT-TAC se constituye como una herramienta nueva que aporta al cirujano una información exacta de la localización de los ganglios centinela, permitiendo orientar de inicio el acto quirúrgico a la búsqueda exclusiva de los ganglios observados en las imágenes (AU)

Introduction. Sentinel lymph node biopsy has become a widely accepted procedure for axillary lymph node staging in patients with breast cancer. Aim. The aim of this study was to determine the advantages of using SPECT-CT instead of planar scintigraphy in the presurgical localisation of sentinel lymph nodes. Methods. We prospectively included 25 consecutive patients with breast cancer who were admitted to our department for SLN localisation. Patients were divided into two groups, depending on whether neoadjuvant chemotherapy had been received (B, n = 6) or not (A, n = 19). Four doses (1.0 mCi each) of 99mTc-nanocolloid were injected intradermallly in all patients, and SPECT-CT and planar images were acquired. All patients underwent surgery and SLN localisation with a hand-held gamma probe. Any axillary “hot spots” were resected. The kappa index (ki) was calculated using surgical findings as the gold standard. Results. In group A, the SLN was correctly detected in 17/19 patients (89.5 %) with SPECT-CT and in 12/19 (63.2%) with planar images. The correlation between SPECT-CT and surgical findings (ki 0.91) was better than between planar images and surgical findings (ki 0.57). In group B, the results of SPECT-CT and planar images were identical, with accurate localisation of the SLN in 5/6 patients (ki 0.76). Conclusions. The results of this study suggest that SPECT-CT may be useful for locating the SLN in breast cancer patients, as it provides accurate localization of the SLN with useful anatomical information. This may allow the surgeon to search exclusively for SLN viewed on SPECT-CT, and avoid false negative and false positive results (AU)

[Early response to treatment with Glivec detected with 18F-FDG PET in a patient with gastrointestinal stromal tumor]. / PET 18F-FDG en la detección temprana de la respuesta al tratamiento con Glivec en paciente con tumor del estroma gastrointestinal.

We present the case of a male patient with gastrointestinal stromal tumor (GIST) in whom we conducted two (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) studies, the first one prior to beginning the treatment with Glivec and the second after one month of treatment. The first (18)F-FDG PET scan detected multiple FDG avid foci in distal esophagus, liver and in an interaortocava lymph node. The second (18)F-FDG PET showed very good response to therapy, with an almost complete disease remission. After 23 months of follow-up, the early response to treatment detected by (18)F-FDG PET was confirmed. The utility of (18)F-FDG PET in the evaluation of response to treatment in GIST is discussed and compared with CT.

PET 18F-FDG en la detección temprana de la respuesta al tratamiento con Glivec® en paciente con tumor del estroma gastrointestinal / Early response to treatment with Glivec® detected with 18F-FDG PET in a patient with gastrointestinal stromal tumor

Presentamos el caso de un paciente con tumor del estroma gastrointestinal (GIST) en el que se realizaron dos estudios de tomografía por emisión de positrones (PET) con 18F-fluorodeoxiglucosa (18F-FDG), el primero antes de iniciar tratamiento con Glivec y el segundo al mes del inicio del tratamiento. La primera PET 18F-FDG detectó múltiples lesiones en el esófago distal, el hígado y en una adenopatía interaortocava. La segunda PET 18F-FDG mostró muy buena respuesta al tratamiento, con una remisión prácticamente completa de la enfermedad. Tras un seguimiento de 23 meses se confirma la respuesta metabólica detectada precozmente con PET 18F-FDG. Se discute la utilidad de la PET 18F-FDG en la valoración de la respuesta al tratamiento en el GIST y se compara con la tomografía axial computarizada (TAC)

We present the case of a male patient with gastrointestinal stromal tumor (GIST) in whom we conducted two 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) studies, the first one prior to beginning the treatment with Glivec® and the second after one month of treatment. The first 18F-FDG PET scan detected multiple FDG avid foci in distal esophagus, liver and in an interaortocava lymph node. The second 18F-FDG PET showed very good response to therapy, with an almost complete disease remission. After 23 months of follow-up, the early response to treatment detected by 18F-FDG PET was confirmed. The utility of 18F-FDG PET in the evaluation of response to treatment in GIST is discussed and compared with CT

[Diagnostic accuracy of 18F-FDG PET in residual or recurrent differentiated thyroid carcinoma with high thyroglobulin and negative 131-I whole-body scan]. / Eficacia diagnóstica de la PET 18F-FDG en el cáncer diferenciado de tiroides residual o recurrente con tiroglobulina elevada y rastreo con 131-I negativo.

INTRODUCTION: 18F-FDG PET has demonstrated its usefulness in detecting recurrences of differentiated thyroid cancer (DTC) with high thyroglobulin (Tg) levels and negative 131I whole-body scan (WBS); however, the number of patients analyzed is low and different studies report disparate results. OBJECTIVE: To estimate the diagnostic accuracy of 18F-FDG PET in this subgroup of patients. MATERIALS AND METHODS: Fifty eight patients (64 18F-FDG PET studies) with histologically proven DTC treated with total thyroidectomy followed by at least one session of 131I therapy for the ablation of thyroid remnants were retrospectively analyzed. Results were verified by pathology, clinical follow-up, response to treatment, or by comparison with conventional diagnostic methods. Sensitivity (Se), specificity (Sp), likelihood ratios (LR), diagnostic accuracy (DA), positive and negative predictive values (PPV, NPV), and Tg levels were calculated for patients with positive and negative 18F-FDG PET results. RESULTS: Twenty seven studies were true positives, 1 false positive, 25 true negatives, and 11 false negatives. Se was 71 %, Sp 96 %, PPV 96.4 %; NPV 69.4 %, DA 81.3 %, positive LR 17.75, and negative LR 0.3. The mean Tg level was 202.34 ng/ml in patients with positive 18F-FDG PET and 40.94 ng/ml in those with negative 18F-FDG PET; the difference between the two groups (161.4 ng/ml) was significant at p <0.05. CONCLUSIONS: 18F-FDG PET is a useful for detecting residual or recurrent DTC in patients with elevated Tg and negative 131I WBS.