García-Vicente Ana María, Tello-Galán María Jesús, Amo-Salas Mariano, Ros-Izquierdo Juan, Jiménez-Londoño German Andrés, La Rosa Salas Beatriz, Prado-Serrano Pradas Guadalupe, Pena-Pardo Francisco José, Soriano-Castrejón Ángel
Nuclear Medicine Department, University General Hospital, C/ Obispo Rafael Torija s/n, 13005, Ciudad Real, Spain.
Mathematics Department, Castilla-La Mancha University, Ciudad Real, Spain.
Ann Nucl Med. 2018 Feb;32(2):123-131. doi: 10.1007/s12149-017-1226-8. Epub 2017 Dec 20.
To assess the influence of clinical features and laboratory test results on the determination of fever of unknown origin (FUO) by means of 18F-FDG PET/CT.
Retrospective and longitudinal analysis, including all the PET/CT studies requested for FUO. Reference standard was established by serology, cultures or biopsy with other laboratory tests or clinical follow-up when necessary. Clinical variables, inflammation markers, protein analysis, serology and culture results close to the PET scan were obtained. The final diagnosis was classified into three groups attending to the etiology; group 1: infection or neoplasm, group 2: vasculitis, autoimmune disease or non-infectious inflammatory disease and group 3: auto-limited fever or persistent fever without diagnosis. PET/CT scans were classified as positive or negative and helpful or not in the diagnosis of the fever origin. The effect of clinical features and laboratory variables on the PET/CT results was analyzed.
Sixty-seven patients were evaluated. The final diagnosis was: Group 1 (25), Group 2 (20) and Group 3 (22). 89.6% of patients had a positive inflammation marker, 28.4% proteinogram alterations and 20.9% positive cultures. PET/CT was positive in 52/67 patients. PET/CT helped in the establishment of the fever origin in 35 cases and was especially helpful in groups 1 and 2. Sensitivity, specificity and accuracy of PET/CT were: 84, 31 and 61%. PET results shown significant relations with the final diagnosis (p = 0.035) and culture results (p = 0.037). No significant relations were observed with the rest of clinical or laboratory variables.
18F-FDG PET/CT had a high sensitivity but a low specificity in the diagnosis of the fever origin, probably due to the high rate of diffuse and auto-limited aetiologies. Patients who are most likely to benefit from the PET/CT study would be those with several positive inflammation markers, reflecting a higher pre-test probability of active disease.
通过18F-FDG PET/CT评估临床特征和实验室检查结果对不明原因发热（FUO）诊断的影响。
进行回顾性纵向分析，纳入所有因FUO进行的PET/CT检查。参考标准通过血清学、培养或活检，并在必要时结合其他实验室检查或临床随访来确定。获取PET扫描前后的临床变量、炎症标志物、蛋白分析、血清学和培养结果。最终诊断根据病因分为三组；第1组：感染或肿瘤，第2组：血管炎、自身免疫性疾病或非感染性炎症性疾病，第3组：自限性发热或未明确诊断的持续性发热。PET/CT扫描分为阳性或阴性，以及对发热病因诊断是否有帮助。分析临床特征和实验室变量对PET/CT结果的影响。
共评估了67例患者。最终诊断为：第1组（25例），第2组（20例）和第3组（22例）。89.6%的患者炎症标志物呈阳性，28.4%有蛋白电泳改变，20.9%培养结果呈阳性。67例患者中52例PET/CT呈阳性。PET/CT对35例患者的发热病因诊断有帮助，在第1组和第2组中尤其有用。PET/CT的敏感性、特异性和准确性分别为：84%、31%和61%。PET结果与最终诊断（p = 0.035）和培养结果（p = 0.037）显示出显著相关性。与其他临床或实验室变量未观察到显著相关性。
18F-FDG PET/CT在发热病因诊断中具有较高的敏感性，但特异性较低，这可能是由于弥漫性和自限性病因的发生率较高。最有可能从PET/CT检查中获益的患者是那些有多个炎症标志物呈阳性的患者，这反映了疾病活动的较高预检概率。
