The Usefulness of Pre-Operative Extra-Cranial Imaging in Radiologically Suspicious Glioblastoma Multiforme in the West of Scotland: and a Proposal of an Imaging Diagnostic Pathway

Abstract AIMS Objective: a CT chest, abdomen and pelvis (CT CAP) is probably unnecessary if a glioblastoma multiforme (GBM) is detected on initial CT brain (CTB) prior to definitive MRI. We audited its frequency to develop a management pathway METHOD Methods: 12-month retrospective case series from 2018 of patients having an initial CTB suspicious for GBM. We dichotomised patients into two groups a) tissue proven and b) non-tissue proven, due to these representing distinct patient profiles. We quantified frequencies of plain and contrast CTBs, CT CAPs and extra-cranial malignancy. RESULTS Results: Group 1 (total n=84 [mean age 59 years]): 64% had a CT CAP. Plain CTB occurred in 24% and contrast CTB in 76%. Extra-cranial malignancy was 8% and 12%. Group 2 (total n=47 [mean age 73 years]): 85% had a CT CAP. Plain CTB occurred in 22% and contrast CTB in 78%. Extra-cranial malignancy was 33% and 23%. Negative CT CAPs in ~88% of CTBs in Group 1 and ~75% of CTBs in Group 2. CONCLUSION Conclusions: patients having a contrast CTB as their initial imaging modality, being suggestive of GBM, prior to definitive MRI, and managed surgically, having no history of extra-cranial malignancy, do not need a CT CAP unless MRI is non-diagnostic.