Department of Neurology and Brain Tumor Center, University Hospital and University of Zurich, Frauenklinikstrasse 26, CH-8091, Zurich, Switzerland.
Department of Neurology and Brain Tumor Center, University Hospital and University of Zurich, Frauenklinikstrasse 26, CH-8091, Zurich, Switzerland.
Eur J Cancer. 2018 Jun;96:64-72. doi: 10.1016/j.ejca.2018.03.010. Epub 2018 Apr 17.
In 30% of patients with brain metastasis (BM), neurological symptoms are the first clinical manifestation of systemic malignancy, referred to as BM from cancer of unknown primary site (BM-CUPS). Here, we define the diagnostic value of F-fluordesoxyglucose positron emission tomography (FDG-PET/CT) in the workup of BM-CUPS.
We screened 565 patients operated for BM at the University Hospital Zurich and identified 64 patients with BM-CUPS with data on both FDG-PET/CT and contrast-enhanced chest/abdomen computed tomography (CT) available at BM diagnosis. A cohort of 125 patients with BM-CUPS from Lille and Vienna was used for validation.
FDG-PET/CT was not superior to chest/abdomen CT in localising the primary lesion in the discovery cohort, presumably because most primary tumours were lung cancers. However, FDG-PET/CT identified additional lesions suspicious of extracranial metastases in 27 of 64 patients (42%). The inclusion of FDG-PET/CT findings shifted the graded prognostic assessment (GPA) score from 3 with CT alone to 2.5 for PET/CT (p = 3.8 × 10, Wilcoxon's test), resulting in a predicted survival of 5.3 versus 3.8 months (p = 6.1 × 10; Wilcoxon's test). All observations were confirmed in the validation cohort.
Lung cancers are the most common primary tumour in BM-CUPS; accordingly, CT alone shows similar overall sensitivity for detecting the primary tumour as FDG-PET/CT. Yet, FDG-PET/CT improves the accuracy of staging by detecting more metastases, reflected by decreased GPA scores and decreased predicted survival. Therefore, randomised trials on patients with BM should standardise methods of staging, notably when stratifying for GPA.
在 30%的脑转移（BM）患者中，神经系统症状是全身恶性肿瘤的首发临床表现，称为原发灶不明的脑转移癌（BM-CUPS）。在这里，我们定义 F-氟脱氧葡萄糖正电子发射断层扫描（FDG-PET/CT）在 BM-CUPS 检查中的诊断价值。
我们筛选了苏黎世大学医院接受 BM 手术的 565 名患者，并确定了 64 名 BM-CUPS 患者，这些患者在 BM 诊断时均有 FDG-PET/CT 和对比增强的胸部/腹部 CT 数据。来自里尔和维也纳的 125 名 BM-CUPS 患者的队列用于验证。
FDG-PET/CT 在发现队列中定位原发性肿瘤的能力并不优于胸部/腹部 CT，这可能是因为大多数原发性肿瘤是肺癌。然而，FDG-PET/CT 在 64 名患者中的 27 名（42%）中发现了其他疑似颅外转移的病灶。纳入 FDG-PET/CT 结果后，将单独使用 CT 时的分级预后评估（GPA）评分从 3 分变为 2.5 分（PET/CT，p=3.8×10，Wilcoxon 检验），导致预测生存时间从 3.8 个月延长至 5.3 个月（p=6.1×10；Wilcoxon 检验）。所有观察结果在验证队列中均得到证实。
肺癌是 BM-CUPS 中最常见的原发性肿瘤；因此，单独使用 CT 对检测原发性肿瘤的总体敏感性与 FDG-PET/CT 相似。然而，FDG-PET/CT 通过检测更多的转移瘤来提高分期的准确性，这反映在 GPA 评分降低和预测生存期缩短。因此，对于 BM 患者的随机试验应标准化分期方法，特别是在分层 GPA 时。
