title: Practical surgical indicators to identify candidates for radical resection of insulo-opercular gliomas.
abstract: OBJECTIVE
  Maximum resection of gliomas with minimum surgical complications usually leads to optimum outcomes for patients. Radical resection of insulo-opercular gliomas is still challenging, and selection of ideal patients can reduce risk and obtain better outcomes.
  
  
  METHODS
  This retrospective study included 83 consecutively treated patients with newly diagnosed gliomas located at the insulo-opercular region and extending to the sylvian fissure around the primary motor and somatosensory cortices. The authors selected 4 characteristics as surgical indicators: clear tumor boundaries, negative enhancement, intact lenticulostriate arteries, and intact superior extremity of the central insular sulcus.
  
  
  RESULTS
  Univariate analysis showed that tumors with clear boundaries were associated with higher rates of gross-total resection than were tumors with ambiguous boundaries (75.7% vs 19.6%). Tumors with negative enhancement compared with enhanced tumors were associated with lower frequency of tumor progression (32.0% vs 81.8%, respectively) and lower rates of surgical complications (14.0% vs 45.5%, respectively). Tumors with intact lenticulostriate arteries were associated with higher rates of gross-total resection than were tumors with involved lenticulostriate arteries (67.3% vs 11.8%, respectively). Tumors with intact superior extremity of the central insular sulcus were associated with higher rates of gross-total resection (57.4% vs 20.7%, respectively) and lower rates of surgical complications (18.5% vs 41.4%, respectively) than were tumors with involved anatomical structures. Multivariate analysis showed that clear tumor boundaries were independently associated with gross-total resection (p < 0.001). Negative enhancement was found to be independently associated with surgical complications (p = 0.005), overall survival times (p < 0.001), and progression-free survival times (p = 0.004). Independent associations were also found between intact lenticulostriate arteries and gross-total resection (p < 0.001), between intact lenticulostriate arteries and progression-free survival times (p = 0.026), and between intact superior extremity of the central insular sulcus and gross-total resection (p = 0.043). Among patients in whom all 4 indicators were present, prognosis was good (5-year survival rate 93.3%), resection rate was maximal (gross-total resection 100%), and surgical complication rate was minimal (6.7%). Also among these patients, overall rates of survival (p = 0.003) and progression-free survival (p = 0.005) were significantly higher than among patients in whom fewer indicators were present.
  
  
  CONCLUSIONS
  The authors propose 4 simple indicators that can be used to identify ideal candidates for radical resection of insulo-opercular gliomas, improve the outcomes, and promote maximum resection without introducing neurological complications. The indicators are clear tumor boundaries, negative enhancement, intact lenticulostriate arteries, and intact superior extremity of the central insular sulcus.
authors.affiliation: Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kumabe
authors.forename: Ryuta
authors.initials: R
authors.lastname: Saito
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanamori
authors.forename: Masaki
authors.initials: M
authors.lastname: Iwasaki
authors.forename: Yoji
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Sonoda
authors.forename: Teiji
authors.initials: T
authors.lastname: Tominaga
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000473:pathology* / Q000601:surgery*; D002536:Cerebral Arteries / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology* / Q000601:surgery*; D002648:Child; D005260:Female; D005910:Glioma / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000453:epidemiology / Q000209:etiology; D019635:Neurosurgical Procedures / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
keywords: glioma; insulo-operculum; oncology; outcome; surgery; surgical indication