Usefulness of preoperative extracranial imaging in radiologically suspicious glioblastoma in the West of Scotland and proposal of an imaging diagnostic pathway

A computed tomography chest, abdomen and pelvis scan (CT CAP) is probably unnecessary if a glioblastoma is detected on the initial CT brain (CTB) before more radiologically definitive magnetic resonance imaging (MRI). We audited its frequency to develop and improve our diagnostic management pathway. Twelve-month retrospective case series from 2018 of patients having an initial CTB suspicious for glioblastoma. We dichotomised patients into two groups: Group 1, tissue proven; and Group 2, non-tissue proven, owing to increased extracranial comorbidity in Group 2, which might influence a medical decision to request a CT CAP despite the radiological diagnosis of a glioblastoma being obvious on an initial CT. We quantified the frequencies of plain and contrast CTBs, CT CAPs and extracranial malignancy. In total, 131 patients had a CTB suspicious for glioblastoma; of these, 72% had a CT CAP and 17% had extracranial malignancy. In Group 1 ( = 84 [mean age 59 years]), 64% had a CT CAP. Plain CTB was undertaken in 24% of patients and contrast CTB in 76%. Extracranial malignancy was present in 8% and 12%. In Group 2 ( = 47 [mean age 73 years]), 85% had a CT CAP. Plain CTB was undertaken in 22% of patients and contrast CTB in 78%. Extracranial malignancy was present in 33% and 23%. Negative CT CAPs were found in ∼88% of CTBs in Group 1 and ∼75% of CTBs in Group 2. Patients having an initial contrast CTB suggestive of glioblastoma, prior to definitive MRI, who are going to be managed surgically, having no history of extracranial malignancy, do not necessarily need a CT CAP unless MRI is non-diagnostic.