Hallazgo incidental de captación focal del colon en estudios 18F-FDG PET/TC / Incidental focal colonic uptake in studies 18F-FDG PET/CT

Objetivos. Evaluar la frecuencia de la captación focal de colon como observación incidental en estudios 18F-FDG PET/TC. Correlacionar dicho hallazgo con resultados histopatológicos. Material y métodos. Se analizaron de forma sistemática 30 estudios en los que se constató captación focal del colon de un total de 3.176 PET/TC con 18F-FDG. Se excluyeron pacientes con neoplasia colorrectal conocida. Se consignó el valor del SUV máximo (SUVm) y el hallazgo morfológico de la TC. Los estudios fueron informados por un médico radiólogo y un médico nuclear. Los hallazgos fueron correlacionados con la endoscopia y la anatomía patológica. Resultados. De los 30 pacientes con lesiones focales hipermetabólicas del colon (0,94%), 15 eran hombres y 15 mujeres con edades comprendidas entre los 27 y 73 años (media 55 años). Los motivos de realización de la PET/TC fueron: cáncer broncopulmonar (4), cáncer de mama (4), tumor de origen desconocido (4), melanoma (3), carcinoma renal (3), neoplasia de cuello uterino (2), adenocarcinoma de ovario (2) y otros (8). Se realizaron 23 fibrocolonoscopias (FCC): 10 pacientes (43,4%) presentaron lesiones malignas, 6 pacientes (26,1%) lesiones premalignas y en 7 pacientes (30,4%) no se identificó ninguna lesión o esta fue benigna. En 7 pacientes no se hizo endoscopia por diversos motivos (rechazo del paciente para realizar el estudio, enfermedad oncológica avanzada). Se correlacionó con valores de SUVm y no se encontraron diferencias estadísticamente significativas entre lesiones malignas-premalignas y las lesiones benignas. Conclusiones. La captación focal en colon de 18F-FDG tiene relevancia clínica sobre todo asociada a lesión morfológica en TC, puede tratarse de un segundo tumor o una lesión premaligna. Se recomienda que todas las captaciones focales del colon sean valoradas con endoscopia, tengan o no alteraciones en TC (AU)

Objectives. To assess the frequency of focal colonic uptake as an incidental observation in 18F-FDG PET/CT studies, and to correlate this finding with histopathological results. Material and methods. Out of a total of 3,176 PET/CT studies with 18F-FDG systematic analysis was carried out on 30 studies in which colonic focal uptake was observed. Patients with known colorectal neoplasia were excluded. The maximum standardised uptake values (SUVm) and the morphological findings provided by the CT were recorded. The studies were reported by a radiologist and a nuclear medicine doctor. The findings were compared with endoscopy and pathology findings. Results. Of the 30 patients with focal hypermetabolic lesions of the colon (0.94%), 15 were men and 15 were women with ages between 27 and 73 (mean 55 years). The reasons for PET/CT were bronchopulmonary cancer (4), breast cancer (4), tumour of unknown origin (4), melanoma (3), renal carcinoma (3), cervical neoplasia (2), adenocarcinoma of ovary (2), and others (8). Of the 23 colonoscopies performed, 10 patients (43.4%) had malignant lesions, 6 (26.1%) had pre-malignant lesions, and in 7 patients (30.4%) no lesion was identified or was benign. No endoscopy was performed on 7 patients for various reasons (patient refusal to perform the study, advanced oncological disease). An analysis was performed with the SUVm, with no statistically significant differences being found between malignant-premalignant lesions and benign lesions. Conclusions. Focal uptake in the colon of 18F-FDG has clinical relevance, and is mainly associated with morphological lesions in CT. It should be evaluated, as it may be a second tumour or a pre-malignant lesion. It is recommended that all focal uptakes of the colon be evaluated with endoscopy (AU)

Incidental focal colonic uptake in studies 18F-FDG PET/CT. / Hallazgo incidental de captación focal del colon en estudios 18F-FDG PET/TC.

OBJECTIVES: To assess the frequency of focal colonic uptake as an incidental observation in 18F-FDG PET/CT studies, and to correlate this finding with histopathological results. MATERIAL AND METHODS: Out of a total of 3,176 PET/CT studies with 18F-FDG systematic analysis was carried out on 30 studies in which colonic focal uptake was observed. Patients with known colorectal neoplasia were excluded. The maximum standardised uptake values (SUVm) and the morphological findings provided by the CT were recorded. The studies were reported by a radiologist and a nuclear medicine doctor. The findings were compared with endoscopy and pathology findings. RESULTS: Of the 30 patients with focal hypermetabolic lesions of the colon (0.94%), 15 were men and 15 were women with ages between 27 and 73 (mean 55 years). The reasons for PET/CT were bronchopulmonary cancer (4), breast cancer (4), tumour of unknown origin (4), melanoma (3), renal carcinoma (3), cervical neoplasia (2), adenocarcinoma of ovary (2), and others (8). Of the 23 colonoscopies performed, 10 patients (43.4%) had malignant lesions, 6 (26.1%) had pre-malignant lesions, and in 7 patients (30.4%) no lesion was identified or was benign. No endoscopy was performed on 7 patients for various reasons (patient refusal to perform the study, advanced oncological disease). An analysis was performed with the SUVm, with no statistically significant differences being found between malignant-premalignant lesions and benign lesions. CONCLUSIONS: Focal uptake in the colon of 18F-FDG has clinical relevance, and is mainly associated with morphological lesions in CT. It should be evaluated, as it may be a second tumour or a pre-malignant lesion. It is recommended that all focal uptakes of the colon be evaluated with endoscopy.

Patologías benignas y variantes que captan 68Ga-DOTATATE en PET/TC / Benign Pathology And Variants With Uptake In 68ga-Dotatate Pet/Ct Studies

Objetivos: Valorar las variantes fisiológicas, anatómicas y lesiones benignas en estudios por tomografía computada por emisión de positrones (PET/TC) con Galio 68 (68Ga)-DOTATATE. Materiales y métodos: Se revisaron en forma retrospectiva los informes de PET/TC con 68Ga-DOTATATE y se seleccionaron aquellos en los cuales se mencionaran palabras en el reporte relacionadas a variantes anatómicas, fisiológicas y tumores benignos. El grado de captación del 68Ga-DOTATATE fue evaluado de forma cualitativa y cuantitativa mediante la medición del valor estandarizado de captación máximo (SUVmax). Se consignó la localización del hallazgo, el valor de SUVmax y la imagen morfológica por tomografía computada (TC). Todos los casos fueron controlados mediante evolución clínica y hallazgos imagenológicos. Resultados: De un total de 772 informes de PET/TC se obtuvo un total de 28 pacientes con 33 variantes o tumores benignos, 14 mujeres y 14 hombres con edad promedio de 63 años. Las captaciones se clasificaron en cuatro grupos: variantes anatómicas y/o fisiológicas (n = 15), dependientes de la actividad osteoblástica (n=4), dependientes de actividad inflamatoria (n = 10) y tumores benignos no neuro-endócrinos (n = 4). Discusión: Los receptores de somatostatina se localizan no sólo en el sistema neuroendócrino sino también en otros tejidos. Las variantes fisiológicas, anatómicas y tumores benignos que expresan estos receptores pueden inducir a un error diagnóstico. Conclusión: Las variantes fisiológicas y lesiones benignas (tumorales e inflamatorias) pueden captar 68Ga-DOTATATE ya que sus tejidos pueden expresar receptores de somatostatina. El análisis semiológico del componente tomográfico de este método de imágenes híbrido, permite la orientación diagnóstica, optimizando el rendimiento del estudio PET/TC.

Purpose: To evaluate the physiological, anatomical variants and benign lesions in positrón emission computed tomography (PET/CT) studies with 68Ga-DOTATATE. Materials and methods: We retrospectively reviewed PET/CT reports scanned with 68Ga-DOTATATE and selected those that contained words in the report related to anatomical, physiological variants and benign tumors. The degree of 68Ga-DOTATATE uptake was evaluated qualitatively and quantitatively by measuring the standarized uptake max value (SUVmax value). The anatomical location, SUVmax value and morphological CT image findings were recorded. All cases had clinical and imaging follow-up. Results: From a total of 772 PET/CT reports, 28 patients were obtained with 33 benign variants or tumors, 14 females and 14 males with a median age of 63 years. Uptake patterns were classified into four groups: anatomic and physiological variants (15), dependent on osteoblastic activity (4), dependent on inflammatory activity (10) and non-neuro-endocrine benign tumors (4). Discussion: Somatostatin receptors are overexpressed not only in the neuroendocrine system but also in other tissues. Physiological, anatomical variants and benign tumors expressing these receptors may be misleading. In the present work the frequency of this finding is 5.1%. Conclusion: Physiological variants and benign lesions (tumor and inflammatory) can accumulate 68Ga-DOTATATE since their tissues can express somatostatin receptors. The semiologic analysis of the tomographic component of this hybrid method enhances the diagnostic efficacy, optimizing PET/CT study performance.

PET/TC en sarcoidosis asociada a enfermedad oncológica / PET/TC en sarcoidosis asociada a enfermedad oncológica

Objetivos: Considerar el diagnóstico de sarcoidosis y reacción sarcoid-like en pacientes oncológicos controlados por tomografía computada por emisión de positrones (PET/TC), que presentan adenopatías hiliomediastinales hipercaptantes, para evitar errores diagnósticos. Materiales y métodos: Se analizaron retrospectivamente 18 estudios PET/TC realizados durante 3 anos a pacientes con tumores sólidos y linfoma, que presentaron adenopatías hiliomediastinales hipermetabólicas. El patrón morfológico, la distribución y, en algunos casos, la asociación con nódulos pulmonares permitieron plantear como diagnóstico diferencial la sarcoidosis. Resultados: Las enfermedades oncológicas correspondieron a mama (n = 4), próstata (n = 3), ovario (n = 2) y otros (n = 9). En 9 pacientes se obtuvo la confirmación histopatológica. En 7 de los 18 pacientes, las adenopatías fueron catalogadas como benignas por confirmación histológica de sarcoidosis, antracosis o reacción sarcoid-like. En 5 el comportamiento evolutivo fue compatible con benignidad, en 2 la biopsia mostró secundarismo y en los 4 restantes la evolución demostró malignidad. El total de lesiones benignas fue de 12 (66%). Discusión: El hallazgo de adenopatías hiliomediastinales hipermetabólicas con patrón morfológico y de distribución que orientan a sarcoidosis lleva a plantear esta entidad. En pacientes oncológicos, se requiere biopsia para descartar recaída. El uso de nuevos marcadores PET/TC para un diagnóstico diferencial representa un desafío. Los trazadores de síntesis de aminoácidos, como la 18F-fluorotimidina (FLT) y 18F-fluorometiltirosina (FMT), han demostrado ser útiles en la diferenciación entre malignidad y enfermedades granulomatosas. Conclusión: En estudios PET/TC de pacientes oncológicos, la presencia de adenopatías hiliomediastinales bilaterales y simétricas debe plantear sarcoidosis como diagnóstico diferencial.

Purposes: To describe the radiological findings of sarcoidosis or sarcoid-like reactions in cancer patients being monitored by positron emission computed tomography (PET/CT). Materials and methods: A retrospective analysis was performed on 18 PET/CT studies performed over 3 years in patients with lymphomas and solid tumours who presented with hypermetabolic hiliar-mediastinal adenopathies. The morphological pattern of these adenopathies, the distribution, and in some cases the association with pulmonary nodules, might suggest sarcoidosis as a differential diagnosis. Results: Oncological diseases corresponded to breast (4), prostate (3), ovary (2), and others (9). The adenopathies were classified in 7 of the 18 patients as benign after histological confirmation of sarcoidosis, anthracosis or sarcoid-like reaction. The evolutionary behaviour in 5 patients was compatible with benign lesions. The biopsy of 2 patients indicated secondary lesions and malignancy was confirmed by the evolution of the 4 remaining cases. There was a total of 12 (66%) benign lesions. Discussion: Sarcoidosis must be suspected in the presence of hypermetabolic hiliar-mediastinal adenopathies with a characteristic morphological pattern and pulmonary changes. However, biopsy is required to rule out oncological recurrence. The use of new PET/CT markers for differential diagnosis represents a challenge. Aminoacid synthesis tracers such as 18F-fluorothymidine (FLT) and 18F-fluoromethyltyrosine (FMT) are useful in the differentiation between malignancy and granulomatous diseases in oncologic patients. Conclusion: The differential diagnosis of sarcoidosis should be considered in the presence of bilateral symmetric mediastinal hilum lymphadenopathies.