Owing to the relatively indolent nature of most meningioma, ‘active monitoring’ of the residual tumor was used for most patients, and this approach is supported by the finding that very few patients had clinical progression associated with radiological growth.28,29 Elevated Ki-67 index has previously been noted to predict time to recurrence in a prospective cohort of surgically treated meningioma consisting of both GTR and STR cases30; however, this was only available for 20 patients within our study, likely representing a highly selected population. This evidence concerns the gene MKI67 and meningioma.