Whole-body Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography for Suspected or Confirmed Brain Metastasis

• Published in: Hong Kong journal of radiology : HKJR = Xianggang fang she ke yi xue za zhi 2012-06, Vol.15 (2), p.80
• Main Authors: Lee, RKL, Wang, K, Ng, AWH, Ip, C B, Lam, JSY, Yuen, EHY, Cheung, TCY, Lee, YYP, Chan, T M
• Format: Article
• Language: English
• Subjects: Biopsy; Brain cancer; Breast cancer; Cancer; Chemotherapy; Medical imaging; Metastasis; Radiation therapy; Tomography
• ISSN: 2223-6619; 2307-4620

Objective: To determine the role of whole-body fluorodeoxyglucose positron emission tomography–computed tomography (FDG PET-CT) in the diagnosis and work-up of suspected or confirmed brain metastasis and to assess its impact on clinical management and outcomes. Methods:This was a retrospective study of patients who were suspected or confirmed to have brain metastases and had subsequent whole-body PET-CT at a local centre between 2008 and 2011. The PET-CT results were then compared with the biopsy results which were regarded as the gold standard. The clinical management and survival rate were also evaluated. Results:In all, 58 consecutive patients with suspected or confirmed brain metastasis who underwent whole-body PET-CT were assessed. Among these, 23 patients suffered from multiple brain lesions and in the remainder it was solitary. Eight (group A) of these 58 patients had a biopsy- or resection-confirmed metastatic brain lesion (primary not proven) prior to the PET-CT scan. While the rest (group B, n = 50) had a clinically suspected brain metastasis without histological confirmation prior to the PET-CT. All patients in group A had a solitary brain lesion. Resection or biopsy of the brain lesion prior to the scan and subsequent histology confirmed its metastatic origin. The site of the extracranial primary malignancy was identified in all these patients by PET-CT. Half of them (4/8) later had biopsies of the PET-CT–suspected extracranial primary malignancies, which were all concordant with the brain biopsy results. In group B, 19 PET-CT scans revealed no suspicious uptake extracranially, so the brain lesions were presumed to be primarily of brain origin (termed group B1). Moreover, all of them were also confirmed by subsequent biopsy. Among the remaining 31 patients (termed group B2), 21 were found to have a suspected extracranial primary malignancy based on PET-CT scans that were confirmed by subsequent biopsy (18 non– small-cell lung carcinoma, 1 colonic carcinoma, 1 breast carcinoma, and 1 thymic carcinoma). For brain lesions of patients in whom the PET-CT scan suggested a metastatic origin (groups A + B2), 70% and 49% received wholebrain radiotherapy and chemotherapy, respectively. On the other hand, patients with primary brain lesions (group B1) underwent resection (74%), radiotherapy (68%), and chemotherapy (53%). The survival of the three groups differed significantly (p