Adam S. Wu, Victoria T. Trinh, Dima Suki, Susan Graham, Arthur Forman, Jeffrey S. Weinberg, Ian E. McCutcheon, Sujit S. Prabhu, Amy B. Heimberger, Raymond Sawaya, Xuemei Wang, Wei Qiao, Kenneth R. Hess and Frederick F. Lang
Seizures are a potentially devastating complication of resection of brain tumors. Consequently, many neurosurgeons administer prophylactic antiepileptic drugs (AEDs) in the perioperative period. However, it is currently unclear whether perioperative AEDs should be routinely administered to patients with brain tumors who have never had a seizure. Therefore, the authors conducted a prospective, randomized trial examining the use of phenytoin for postoperative seizure prophylaxis in patients undergoing resection for supratentorial brain metastases or gliomas.
Patients with brain tumors (metastases or gliomas) who did not have seizures and who were undergoing craniotomy for tumor resection were randomized to receive either phenytoin for 7 days after tumor resection (prophylaxis group) or no seizure prophylaxis (observation group). Phenytoin levels were monitored daily. Primary outcomes were seizures and adverse events. Using an estimated seizure incidence of 30% in the observation arm and 10% in the prophylaxis arm, a Type I error of 0.05 and a Type II error of 0.20, a target accrual of 142 patients (71 per arm) was planned.
The trial was closed before completion of accrual because Bayesian predictive probability analyses performed by an independent data monitoring committee indicated a probability of 0.003 that at the end of the study prophylaxis would prove superior to observation and a probability of 0.997 that there would be insufficient evidence at the end of the trial to choose either arm as superior. At the time of trial closure, 123 patients (77 metastases and 46 gliomas) were randomized, with 62 receiving 7-day phenytoin (prophylaxis group) and 61 receiving no prophylaxis (observation group). The incidence of all seizures was 18% in the observation group and 24% in the prophylaxis group (p = 0.51). Importantly, the incidence of early seizures (< 30 days after surgery) was 8% in the observation group compared with 10% in the prophylaxis group (p = 1.0). Likewise, the incidence of clinically significant early seizures was 3% in the observation group and 2% in the prophylaxis group (p = 0.62). The prophylaxis group experienced significantly more adverse events (18% vs 0%, p < 0.01). Therapeutic phenytoin levels were maintained in 80% of patients.
The incidence of seizures after surgery for brain tumors is low (8% [95% CI 3%–18%]) even without prophylactic AEDs, and the incidence of clinically significant seizures is even lower (3%). In contrast, routine phenytoin administration is associated with significant drug-related morbidity. Although the lower-than-anticipated incidence of seizures in the control group significantly limited the power of the study, the low baseline rate of perioperative seizures in patients with brain tumors raises concerns about the routine use of prophylactic phenytoin in this patient population.
Marcos V. C. Maldaun, Shumaila N. Khawja, Nicholas B. Levine, Ganesh Rao, Frederick F. Lang, Jeffrey S. Weinberg, Sudhakar Tummala, Charles E. Cowles, David Ferson, Anh-Thuy Nguyen, Raymond Sawaya, Dima Suki and Sujit S. Prabhu
The object of this study was to describe the experience of combining awake craniotomy techniques with high-field (1.5 T) intraoperative MRI (iMRI) for tumors adjacent to eloquent cortex.
From a prospective database the authors obtained and evaluated the records of all patients who had undergone awake craniotomy procedures with cortical and subcortical mapping in the iMRI suite. The integration of these two modalities was assessed with respect to safety, operative times, workflow, extent of resection (EOR), and neurological outcome.
Between February 2010 and December 2011, 42 awake craniotomy procedures using iMRI were performed in 41 patients for the removal of intraaxial tumors. There were 31 left-sided and 11 right-sided tumors. In half of the cases (21 [50%] of 42), the patient was kept awake for both motor and speech mapping. The mean duration of surgery overall was 7.3 hours (range 4.0–13.9 hours). The median EOR overall was 90%, and gross-total resection (EOR ≥ 95%) was achieved in 17 cases (40.5%). After viewing the first MR images after initial resection, further resection was performed in 17 cases (40.5%); the mean EOR in these cases increased from 56% to 67% after further resection. No deficits were observed preoperatively in 33 cases (78.5%), and worsening neurological deficits were noted immediately after surgery in 11 cases (26.2%). At 1 month after surgery, however, worsened neurological function was observed in only 1 case (2.3%).
There was a learning curve with regard to patient positioning and setup times, although it did not adversely affect patient outcomes. Awake craniotomy can be safely performed in a high-field (1.5 T) iMRI suite to maximize tumor resection in eloquent brain areas with an acceptable morbidity profile at 1 month.
Wael Hassaneen, Nicholas B. Levine, Dima Suki, Abhijit L. Salaskar, Alessandra de Moura Lima, Ian E. McCutcheon, Sujit S. Prabhu, Frederick F. Lang, Franco DeMonte, Ganesh Rao, Jeffrey S. Weinberg, David M. Wildrick, Kenneth D. Aldape and Raymond Sawaya
Multiple craniotomies have been performed for resection of multiple brain metastases in the same surgical session with satisfactory outcomes, but the role of this procedure in the management of multifocal and multicentric glioblastomas is undetermined, although it is not the standard approach at most centers.
The authors performed a retrospective analysis of data prospectively collected between 1993 and 2008 in 20 patients with multifocal or multicentric glioblastomas (Group A) who underwent resection of all lesions via multiple craniotomies during a single surgical session. Twenty patients who underwent resection of solitary glioblastoma (Group B) were selected to match Group A with respect to the preoperative Karnofsky Performance Scale (KPS) score, tumor functional grade, extent of resection, age at time of surgery, and year of surgery. Clinical and neurosurgical outcomes were evaluated.
In Group A, the median age was 52 years (range 32–78 years); 70% of patients were male; the median preoperative KPS score was 80 (range 50–100); and 9 patients had multicentric glioblastomas and 11 had multifocal glioblastomas. Aggressive resection of all lesions in Group A was achieved via multiple craniotomies in the same session, with a median extent of resection of 100%. Groups A and B were comparable with respect to all the matching variables as well as the amount of tumor necrosis, number of cysts, and the use of intraoperative navigation. The overall median survival duration was 9.7 months in Group A and 10.5 months in Group B (p = 0.34). Group A and Group B (single craniotomy) had complication rates of 30% and 35% and 30-day mortality rates of 5% (1 patient) and 0%, respectively.
Aggressive resection of all lesions in selected patients with multifocal or multicentric glioblastomas resulted in a survival duration comparable with that of patients undergoing surgery for a single lesion, without an associated increase in postoperative morbidity. This finding may indicate that conventional wisdom of a minimal role for surgical treatment in glioblastoma should at least be questioned.