Department of Emergency and General Internal Medicine, Fujita Health University School of Medicine, Toyoake, Japan.
Department of Radiology, Fujita Health University School of Medicine, Toyoake, Japan.
J Korean Med Sci. 2021 Jun 7;36(22):e150. doi: 10.3346/jkms.2021.36.e150.
In patients with fever or inflammation of unknown origin (fever of unknown origin [FUO] or inflammation of unknown origin [IUO], respectively), expert consensus recommends the use of positron emission tomography with fluorine-18-fluorodeoxy glucose combined with computed tomography (FDG-PET/CT) when standard work-up fails to identify diagnostic clues. However, the clinical variables associated with successful localization of the cause by FDG-PET/CT remain uncertain. Moreover, the long-term outcomes of patients with unexplained FUO or IUO after negative FDG-PET/CT results are unknown. Therefore, we assessed predictors of successful diagnosis of FUO or IUO caused by FDG-PET/CT and associations of spontaneous remission of symptoms with FDG-PET/CT results.
All patients with FUO or IUO, who underwent FDG-PET/CT from 2013 to 2019 because diagnostic work-up failed to identify a cause, were retrospectively included. We calculated the diagnostic yield and performed multivariable logistic regression to assess characteristics previously proposed to be associated with successful localization of FUO or IUO causes. We also assessed whether the FDG-PET/CT results were associated with spontaneous remissions.
In total, 50 patients with diagnostically challenging FUO or IUO (35 with FUO and 15 with IUO) were assessed. Other than one case of infection, all the identified causes were either malignancy or non-infectious inflammatory diseases (each with 18 patients), and FDG-PET/CT correctly localized the cause in 29 patients (diagnostic yield = 58%). None of the proposed variables was associated with successful localization. All 13 patients with sustained unexplained cause remained alive (median follow-up, 190 days). Spontaneous remission was observed in 4 of 5 patients with a negative FDG-PET/CT, and 1 of 8 with a positive result ( = 0.018).
In the current cohort, the proposed variables were not predictive for successful localization by FDG-PET/CT. A negative FDG-PET/CT scan may be prognostic for spontaneous remission in patients with sustained FUO or IUO.
对于发热或原因不明的炎症患者（分别为发热原因不明[FUO]和炎症原因不明[IUO]），当标准检查未能发现诊断线索时，专家共识建议使用氟-18-氟脱氧葡萄糖正电子发射断层扫描与计算机断层扫描（FDG-PET/CT）。然而，FDG-PET/CT 成功定位病因的临床变量尚不确定。此外，FDG-PET/CT 结果为阴性的不明原因 FUO 或 IUO 患者的长期结局尚不清楚。因此，我们评估了 FDG-PET/CT 成功诊断 FUO 或 IUO 的预测因素，并评估了症状自发缓解与 FDG-PET/CT 结果之间的关系。
回顾性纳入 2013 年至 2019 年间因诊断性检查未能确定病因而接受 FDG-PET/CT 的 FUO 或 IUO 患者。我们计算了诊断率，并进行了多变量逻辑回归分析，以评估先前提出的与 FUO 或 IUO 病因成功定位相关的特征。我们还评估了 FDG-PET/CT 结果是否与自发缓解相关。
共评估了 50 例具有挑战性的 FUO 或 IUO 患者（35 例 FUO 和 15 例 IUO）。除 1 例感染外，所有确定的病因均为恶性肿瘤或非感染性炎症性疾病（各有 18 例），FDG-PET/CT 正确定位了 29 例患者的病因（诊断率=58%）。没有一个提出的变量与成功定位有关。所有 13 例持续原因不明的患者仍存活（中位随访时间为 190 天）。5 例 FDG-PET/CT 阴性的患者中有 4 例自发缓解，8 例 FDG-PET/CT 阳性的患者中有 1 例（=0.018）。
在当前队列中，提出的变量对 FDG-PET/CT 的成功定位没有预测作用。FDG-PET/CT 扫描阴性可能预示着持续 FUO 或 IUO 患者的自发缓解。
