Detection of unexpected emergency diseases using FDG-PET/CT in oncology patients

To evaluate the frequency of emergency diseases that were detected unexpectedly using FDG-PET/CT.

Interpretation reports for 11,663 FDG-PET/CT studies in our hospital were retrospectively reviewed. Patients with major emergency diseases were extracted according to the following exclusion criteria: (1) relevant findings had been recognized prior to the PET/CT; (2) an intervention or operation that may have been relevant to the present findings was performed within 1 month prior to the PET/CT; and (3) the clinical course could not be investigated sufficiently (e.g., in cases where the patients were introduced from other hospitals).

Forty-one patients (0.35%) with unexpected emergency diseases were identified. The most frequent disease was pneumothorax (8 patients), followed by chronic subdural hematoma (CSH) (7 patients), ureteral stone (7 patients), and abdominal aortic aneurysm (AAA) with a dirty fat sign or a high-attenuation crescent sign visualized on CT (4 patients). Nine patients (2 pneumothorax, 3 CSH, 1 cerebral hemorrhage, 1 acute cholecystitis, 1 acute pancreatitis, and 1 acute appendicitis) were hospitalized and/or underwent therapeutic intervention within 1 week after the PET/CT.

Although rare, an unexpected emergency disease requiring urgent management can be detected using FDG-PET/CT in oncology patients.