Efectividad diagnóstica de la tomografía por emisión de positrones con18fluorodeoxiglucosa asociada a tomografía axial en la discriminación de benignidad o malignidad de las lesiones suprarrenales / Diagnostic efficacy and discriminatory capacity of positron emission tomography combined with axial tomography of adrenal lesions

Introducción: Se analiza la utilidad de la tomografía por emisión de positrones asociada a la tomografía axial computarizada (PET-TAC) en el diagnóstico de benignidad o malignidad de lesiones suprarrenales. Material y métodos: Estudio retrospectivo, entre junio de 2005 y mayo de 2009, de una serie consecutiva de pacientes a los que se les realizó una PET-TAC para el estudio de patología suprarrenal con sospecha de malignidad. Se valoraron la presencia de captaciones focales, su valor estándar de máxima captación (SUV), y la ratio del valor máximo suprarrenal/hepático. Se analizó la sensibilidad, especificidad, valor predictivo positivo y negativo de la prueba, y los valores de captación máxima adrenal y la ratio para los que la rentabilidad diagnóstica fue máxima. Resultados: Se incluyeron 15 pacientes. El diagnóstico final reveló malignidad en ocho y benignidad en siete. Diez pacientes presentaron captación suprarrenal: tres en lesiones benignas y siete en neoplasias, con un valor de captación medio de 6,3 (3,2 en benignas y 9 en malignas). La ratio media suprarrenal/hepático fue de 1,8 (0,9 en lesiones benignas y 2,6 en malignas). Cuando se relaciona la presencia de captación suprarrenal con el diagnóstico final de malignidad, obtuvimos una sensibilidad del 87,5%, especificidad del 57,1%, valor predictivo positivo del 70% y negativo del 80%. Un valor de corte de SUV de 6, o una ratio de captación suprarrenal/hepática de 2, proporciona una sensibilidad de 75%, especificidad de 100%, valor predictivo positivo de 100% y negativo de 77,7%. Conclusiones: La PET-TAC posee una alta capacidad para discriminar entre benignidad o malignidad en la patología adrenal estudiada (AU)

Introduction: The usefulness of 18fluorodeoxyglucose positron emission tomography combined with axial tomography (PET-CT) in diagnosing whether adrenal tumours are benign or malignant is assessed. Material and methods: A retrospective study conducted between June 2005 and May 2009 on a consecutive series of patients on whom a PET-CT scan was performed to study suspected malignant adrenal disease. Focal uptakes were assessed, along with the maximum standard uptake value (SUV), and the ratio of the maximum adrenal/hepatic value. The sensitivity, specificity, positive and negative predictive value of the test, the maximum adrenal uptake values and the ratio for those where the diagnostic yield was maximum. Results: Fifteen patients were included. The final diagnosis showed malignancy in eight and seven were benign. Ten patients had adrenal uptake: three in benign lesions and seven in neoplasias, with a mean uptake value of 6.3 (3.2 in benign lesions and 9.0 in malignant lesions). The mean adrenal/hepatic ratio was 1.8 (0.9 in benign and 2.6 in malignant lesions). When the presence of adrenal uptake is associated with a final diagnosis of malignancy, we obtained a sensitivity of 87.5%, a specificity of 57.1%, and a positive and negative predictive value of 70% and 80%, respectively. An SUV cut-off value of 6, or an adrenal/hepatic uptake ratio of 2, gave a sensitivity of 75%, a specificity of 100%, and a positive and negative predictive value of 100% and 77.7%, respectively. Conclusions: PET-CT has a high ability to discriminate between benign and malignant lesions in the adrenal disease studied (AU)

[Diagnostic efficacy and discriminatory capacity of positron emission tomography combined with axial tomography of adrenal lesions]. / Efectividad diagnóstica de la tomografía por emisión de positrones con (18)fluorodeoxiglucosa asociada a tomografía axial en la discriminación de benignidad o malignidad de las lesiones suprarrenales.

INTRODUCTION: The usefulness of 18fluorodeoxyglucose positron emission tomography combined with axial tomography (PET-CT) in diagnosing whether adrenal tumours are benign or malignant is assessed. MATERIAL AND METHODS: A retrospective study conducted between June 2005 and May 2009 on a consecutive series of patients on whom a PET-CT scan was performed to study suspected malignant adrenal disease. Focal uptakes were assessed, along with the maximum standard uptake value (SUV), and the ratio of the maximum adrenal/hepatic value. The sensitivity, specificity, positive and negative predictive value of the test, the maximum adrenal uptake values and the ratio for those where the diagnostic yield was maximum. RESULTS: Fifteen patients were included. The final diagnosis showed malignancy in eight and seven were benign. Ten patients had adrenal uptake: three in benign lesions and seven in neoplasias, with a mean uptake value of 6.3 (3.2 in benign lesions and 9.0 in malignant lesions). The mean adrenal/hepatic ratio was 1.8 (0.9 in benign and 2.6 in malignant lesions). When the presence of adrenal uptake is associated with a final diagnosis of malignancy, we obtained a sensitivity of 87.5%, a specificity of 57.1%, and a positive and negative predictive value of 70% and 80%, respectively. An SUV cut-off value of 6, or an adrenal/hepatic uptake ratio of 2, gave a sensitivity of 75%, a specificity of 100%, and a positive and negative predictive value of 100% and 77.7%, respectively. CONCLUSIONS: PET-CT has a high ability to discriminate between benign and malignant lesions in the adrenal disease studied.