Impact of maximal extent of resection on postoperative deficits, patient functioning, and survival within clinically important glioblastoma subgroups.

BACKGROUND: The impact of extent of resection (EOR), residual tumor volume (RTV), and gross-total resection (GTR) in glioblastoma subgroups is currently unknown. This study aimed to analyze their impact on patient subgroups in relation to neurological and functional outcomes. METHODS: Patients with tumor resection for eloquent glioblastoma between 2010 and 2020 at 4 tertiary centers were recruited from a cohort of 3919 patients. RESULTS: One thousand and forty-seven (1047) patients were included. Higher EOR and lower RTV were significantly associated with improved overall survival (OS) and progression-free survival (PFS) across all subgroups, but RTV was a stronger prognostic factor. GTR based on RTV improved median OS in the overall cohort (19.0 months, P < .0001), and in the subgroups with IDH wildtype tumors (18.5 months, P = .00055), MGMT methylated tumors (35.0 months, P < .0001), aged <70 (20.0 months, P < .0001), NIHSS 0-1 (19.0 months, P = .0038), KPS 90-100 (19.5 months, P = .0012), and KPS ≤80 (17.0 months, P = .036). GTR was significantly associated with improved OS in the overall cohort (HR 0.58, P = .0070) and improved PFS in the NIHSS 0-1 subgroup (HR 0.47, P = .012). GTR combined with preservation of neurological function (OFO 1 grade) yielded the longest survival times (median OS 22.0 months, P < .0001), which was significantly more frequently achieved in the awake mapping group (50.0%) than in the asleep group (21.8%) (P < .0001). CONCLUSIONS: Maximum resection was especially beneficial in the subgroups aged <70, NIHSS 0-1, and KPS 90-100 without increasing the risk of postoperative NIHSS or KPS worsening. These findings may assist surgical decision making in individual glioblastoma patients.

Towards real-time intraoperative tissue interrogation for REIMS-guided glioma surgery.

Introduction: The main goal of brain tumour surgery is to maximize tumour resection while avoiding neurological deficits. Accurate characterization of tissue and delineation of resection margins are, therefore, essential to achieve optimal surgical results. Objectives: The primary objective of this study was to develop and validate a mass spectrometry- based technique for the molecular characterization of high- and low-grade glioma tissue during surgery. Methods: An electrosurgical knife is connected to a mass spectrometer (iKnife). Using this system, an aerosol created during electrosurgical resection is aspirated to a mass spectrometer to determine the molecular profile of the tissue within seconds. This rapid evaporative ionization mass spectrometry (REIMS) technique is used to create a chemical profile database and develop a real-time tissue recognition system based on machine learning. Results: Classification models were built by analysing biopsies from 36 patients who underwent brain tumour resection. Our multivariate statistical model could differentiate between astrocytoma grade II and III, glioblastoma, oligodendroglioma grade II and III, and normal brain tissue with an 88% overall accuracy. Astrocytoma and oligodendroglioma grade II were separated from normal brain with a 96% correct classification rate. REIMS could differentiate between different percentages of GBM with 99.2% sensitivity and different percentages of astrocytoma grade II with 97.5% sensitivity. Conclusion: Real-time information during electrosurgical dissection can improve intra-operative decision-making, leading to a more accurate tumour removal for different glioma subtypes.

Effect of awake craniotomy in glioblastoma in eloquent areas (GLIOMAP): a propensity score-matched analysis of an international, multicentre, cohort study.

BACKGROUND: Awake mapping has been associated with decreased neurological deficits and increased extent of resection in eloquent glioma resections. However, its effect within clinically relevant glioblastoma subgroups remains poorly understood. We aimed to assess the benefit of this technique in subgroups of patients with glioblastomas based on age, preoperative neurological morbidity, and Karnofsky Performance Score (KPS). METHODS: In this propensity score-matched analysis of an international, multicentre, cohort study (GLIOMAP), patients were recruited at four tertiary centres in Europe (Erasmus MC, Rotterdam and Haaglanden MC, The Hague, Netherlands, and UZ Leuven, Leuven, Belgium) and the USA (Brigham and Women's Hospital, Boston, MA). Patients were eligible if they were aged 18-90 years, undergoing resection, had a histopathological diagnosis of primary glioblastoma, their tumour was in an eloquent or near-eloquent location, and they had a unifocal enhancing lesion. Patients either underwent awake mapping during craniotomy, or asleep resection, as per treating physician or multidisciplinary tumour board decision. We used propensity-score matching (1:3) to match patients in the awake group with those in the asleep group to create a matched cohort, and to match patients from subgroups stratified by age (<70 years vs ≥70 years), preoperative National Institute of Health Stroke Scale (NIHSS) score (score of 0-1 vs ≥2), and preoperative KPS (90-100 vs ≤80). We used Cox proportional hazard regressions to analyse the effect of awake mapping on the primary outcomes including postoperative neurological deficits (measured by deterioration in NIHSS score at 6 week, 3 months, and 6 months postoperatively), overall survival, and progression-free survival. We used logistic regression to analyse the predictive value of awake mapping and other perioperative factors on postoperative outcomes. FINDINGS: Between Jan 1, 2010, and Oct 31, 2020, 3919 patients were recruited, of whom 1047 with tumour resection for primary eloquent glioblastoma were included in analyses as the overall unmatched cohort. After propensity-score matching, the overall matched cohort comprised 536 patients, of whom 134 had awake craniotomies and 402 had asleep resection. In the overall matched cohort, awake craniotomy versus asleep resection resulted in fewer neurological deficits at 3 months (26 [22%] of 120 vs 107 [33%] of 323; p=0·019) and 6 months (30 [26%] of 115 vs 125 [41%] of 305; p=0·0048) postoperatively, longer overall survival (median 17·0 months [95% CI 15·0-24·0] vs 14·0 months [13·0-16·0]; p=0·00054), and longer progression-free survival (median 9·0 months [8·0-11·0] vs 7·3 months [6·0-8·8]; p=0·0060). In subgroup analyses, fewer postoperative neurological deficits occurred at 3 months and at 6 months with awake craniotomy versus asleep resection in patients younger than 70 years (3 months: 22 [21%] of 103 vs 93 [34%] of 272; p=0·016; 6 months: 24 [24%] of 101 vs 108 [42%] of 258; p=0·0014), those with an NIHSS score of 0-1 (3 months: 22 [23%] of 96 vs 97 [38%] of 254; p=0·0071; 6 months: 27 [28%] of 95 vs 115 [48%] of 239; p=0·0010), and those with a KPS of 90-100 (3 months: 17 [19%] of 88 vs 74 [35%] of 237; p=0·034; 6 months: 24 [28%] of 87 vs 101 [45%] of 223, p=0·0043). Additionally, fewer postoperative neurological deficits were seen in the awake group versus the asleep group at 3 months in patients aged 70 years and older (two [13%] of 16 vs 15 [43%] of 35; p=0·033; no difference seen at 6 months), with a NIHSS score of 2 or higher (3 months: three [13%] of 23 vs 21 [36%] of 58; p=0·040) and at 6 months in those with a KPS of 80 or lower (five [18%] of 28 vs 34 [39%] of 88; p=0·043; no difference seen at 3 months). Median overall survival was longer for the awake group than the asleep group in the subgroups younger than 70 years (19·5 months [95% CI 16·0-31·0] vs 15·0 months [13·0-17·0]; p<0·0001), an NIHSS score of 0-1 (18·0 months [16·0-31·0] vs 14·0 months [13·0-16·5]; p=0·00047), and KPS of 90-100 (19·0 months [16·0-31·0] vs 14·5 months [13·0-16·5]; p=0·00058). Median progression-free survival was also longer in the awake group than in the asleep group in patients younger than 70 years (9·3 months [95% CI 8·0-12·0] vs 7·5 months [6·5-9·0]; p=0·0061), in those with an NIHSS score of 0-1 (9·5 months [9·0-12·0] vs 8·0 months [6·5-9·0]; p=0·0035), and in those with a KPS of 90-100 (10·0 months [9·0-13·0] vs 8·0 months [7·0-9·0]; p=0·0010). No difference was seen in overall survival or progression-free survival between the awake group and the asleep group for those aged 70 years and older, with NIHSS scores of 2 or higher, or with a KPS of 80 or lower. INTERPRETATION: These data might aid neurosurgeons with the assessment of their surgical strategy in individual glioblastoma patients. These findings will be validated and further explored in the SAFE trial (NCT03861299) and the PROGRAM study (NCT04708171). FUNDING: None.