Imaging Workup of Suspected Classical Paraneoplastic Neurological Syndromes: A Systematic Review and Retrospective Analysis of ¹⁸F-FDG-PET-CT

Rationale and objectives: This study aimed to assess the clinical efficacy of positron emission tomography (PET) or combined PET-computed tomography (CT) with ¹⁸F-fluorodeoxyglucose (FDG) for whole-body cancer screening in patients with suspected paraneoplastic neurological syndromes (PNS). The following main research questions were addressed: What is the percentage of positive findings to be expected in whole-body FDG-PET-CT in adult patients with PNS? How many false positives can be expected as assessed by clinical and histopathological workup? Are there patients who present with a tumor despite initially negative findings?

Materials and methods: This is a systematic review of the literature and retrospective analysis of FDG-PET-CT and clinical follow-up data from 45 consecutive patients (age: 56.6 ± standard deviation 15.8 years, 14 female, 31 male). Suspicious lesions were identified and correlated with immediate workup and clinical follow-up.

Results: Fourteen studies were included in the review. Eleven malignancies (24.4% of patients) were identified by FDG-PET-CT in this sample. This is a higher percentage of positive findings compared to most previous reports. There was one initially negative finding.

Conclusions: Whole-body FDG-PET-CT is suitable to identify additional malignancies in patients with suspected classical PNS referred to a tertiary medical center. The utility by means of true-positive findings is higher in classical PNS than suggested by studies in less select patient populations.