{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T17:55:39Z","timestamp":1792173339159,"version":"4.4.0"},"reference-count":22,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"1","license":[{"start":{"date-parts":[[2020,8,20]],"date-time":"2020-08-20T00:00:00Z","timestamp":1597881600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Neurosurg.","NEUROS"],"published-print":{"date-parts":[[2021,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>Meningiomas are the most common tumors occurring in the central nervous system, with variable recurrence rates depending on World Health Organization grading. Atypical (Grade II) meningioma has a higher rate of recurrence than benign (Grade I) meningioma. The efficacy of adjuvant radiotherapy (RT) to improve tumor control has been questioned.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>OBJECTIVE<\/jats:title>\n                    <jats:p>To investigate clinical and histopathological predictors of tumor recurrence and radio-resistance in atypical meningiomas.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>METHODS<\/jats:title>\n                    <jats:p>This cohort study retrospectively reviewed all patients in St. Michael's Hospital CNS tumor patient database who underwent surgical resection of a Grade II meningioma from 1995 to 2015. Cases with neurofibromatosis type II, multiple satellite tumors, spinal cord meningioma, radiation-induced meningioma, and perioperative death were excluded. Patient demographics, neuropathological diagnosis, tumor location, extent of resection, radiation therapy, and time to recurrence or progression were recorded. Cox univariate regression and Kaplan-Meier survival analysis were employed to identify risk factors for recurrence and radio-resistance.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>RESULTS<\/jats:title>\n                    <jats:p>\n                      Among 181 patients, the combination of necrosis and brain invasion was associated with an increased recurrence risk (hazard ratio [HR]\u00a0=\u00a04.560,\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      \u00a0=\u00a0.001) and the lowest progression-free survival (PFS) relative to other pathological predictors. This trend was maintained after gross total resection (GTR,\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      \u00a0=\u00a0.001). RT was associated with decreased PFS (\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      \u00a0=\u00a0.001), even in patients who received GTR (\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      \u00a0=\u00a0.001).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CONCLUSION<\/jats:title>\n                    <jats:p>The combination of necrosis and brain invasion is a strong predictor of tumor recurrence and radio-resistance in meningioma, regardless of EOR or adjuvant RT. Our findings question the sensibility of brain invasion as an absolute criterion for Grade II status.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/neuros\/nyaa348","type":"journal-article","created":{"date-parts":[[2020,7,10]],"date-time":"2020-07-10T07:31:05Z","timestamp":1594366265000},"page":"E42-E48","source":"Crossref","is-referenced-by-count":26,"title":["Necrosis and Brain Invasion Predict Radio-Resistance and Tumor Recurrence in Atypical Meningioma: A Retrospective Cohort Study"],"prefix":"10.1227","volume":"88","author":[{"given":"Monica Emili","family":"Garcia-Segura","sequence":"first","affiliation":[{"name":"Division of Neurosurgery, University of Toronto, Toronto, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anders Wilder","family":"Erickson","sequence":"additional","affiliation":[{"name":"Institute of Medical Science, University of Toronto, Toronto, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rishi","family":"Jairath","sequence":"additional","affiliation":[{"name":"Division of Neurosurgery, University of Toronto, Toronto, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David G","family":"Munoz","sequence":"additional","affiliation":[{"name":"Institute of Medical Science, University of Toronto, Toronto, Canada"},{"name":"Department of Laboratory Medicine and Pathobiology, St. Michael's Hospital, University of Toronto, Toronto, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2146-4168","authenticated-orcid":false,"given":"Sunit","family":"Das","sequence":"additional","affiliation":[{"name":"Division of Neurosurgery, University of Toronto, Toronto, Canada"},{"name":"Institute of Medical Science, University of Toronto, Toronto, Canada"},{"name":"Li Ka Shing Knowledge Institute, St. Michael's Hospital, University of Toronto, 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