Evaluation of an abbreviated MRI protocol in the screening for brain metastases in the initial staging of lung cancer.

background and purposeIn the routine clinical practice, only a few key sequences allow positive diagnosis of brain metastasis. The aim of our study was to investigate the diagnostic accuracy of a reduced protocol including only 2 sequences of interest for the detection of brain lesions in lung cancer. MATERIALS AND

methodsFifty four patients undergoing MRI in the initial staging of lung cancer were included in this monocentric, retrospective study. Four radiologists reviewed the data from a short protocol with 2 sequences of interest (3D FLAIR and 3D T1w-SE sequences) and from the standard reference protocol (DWI, T2*, 3D FLAIR, non-enhanced T1, post-contrast 3D T1w-GRE and post-contrast 3D T1w-SE sequences). Diagnostic performances were assessed on a per-patient and per-lesion basis.

resultsIn our population, 35% of patients had brain metastases. The short protocol detected 22 metastatic patients with 3 false positives. The analysis showed excellent diagnostic performance of the short protocol with more than 90% sensitivity and specificity, for both per-patient and per-lesion evaluations. Metastatic classification was not significantly influenced by the reviewer's experience. Seven major secondary findings were identified, including 3 ischemic events and 1 aneurysm that were only detected when the long protocol was used.

conclusionsA short MRI brain protocol, including only 3D FLAIR and post-contrast T1w-SE sequences, demonstrated diagnostic accuracy equivalent to standard protocols for BM screening in lung cancer patients. The subsequent reduction in examination time can potentially improve access to MRI.