Medical Student Faculty of Medicine, University of British Columbia, British Columbia, Canada
Introduction: Meningiomas are the most common primary intracranial tumours accounting for 1/3rd of all primary central nervous system lesions. Maximal safe resection is the standard of care and adjuvant radiation therapy (aRT) may be used in the management of atypical and recurrent tumours. The global efficacy of aRT is under investigation, especially in management of Grade 1 lesions which have not classically been referred on to aRT. Understanding the long-term patterns and locations of Grade 1 meningioma recurrence may assist in tailoring surgical management and recommendations to proceed with aRT.
Methods: A retrospective chart review was performed for all patients at a single institution who had undergone initial surgical management of WHO grade 1 meningiomas between 2000 and 2021. Demographic information, presenting tumour characteristics, extent of initial surgical resection (Simpson grade), time to recurrence, and location of recurrence were collected. Location of recurrence defined as within initial tumour bed, < 1 cm from initial tumour margin, and >1 cm from initial margin was compared by Simpson grade of initial resection, WHO grade of recurrence, and tumour location of origin.
Results: 1078 patients underwent resection of a WHO grade 1 meningioma at Vancouver General Hospital, of which 180 (16.7%) were determined to have had a recurrence. 42 (3.9%) patients were eligible participants after accounting for the exclusion criteria, which included neurofibromatosis type 2 diagnosis, missing documents, subsequent upgraded diagnosis to atypical meningioma, and subtotal resection. The majority of recurrences occurred within the resection bed or < 1 cm from the tumour margin as compared to >1 cm from initial tumour margin. Recurrence occurred more often in patients with higher Simpson grade resection.
Conclusion : Targeting a margin of up to 1 cm beyond the initial tumour margin with aRT may be beneficial in the management of WHO grade 1 meningiomas with Simpson grade >1.
