Impact of surgical methodology on the complication rate and functional outcome of patients with a single brain metastasis
Authors: Patel Akash J. , Suki Dima , Hatiboglu Mustafa Aziz , Rao Vikas Y. , Fox Benjamin D. , Sawaya Raymond 
Published: March 2015

OBJECT
Brain metastases are the most common intracranial neoplasms and are on the increase. As radiation side effects are increasingly better understood, more patients are being treated with surgery alone with varying outcomes. The authors previously reported that en bloc resection of a single brain metastasis was associated with decreased incidences of leptomeningeal disease and local recurrence compared with piecemeal resection. However, en bloc resection is often feared to cause an increased incidence of postoperative complications. This study aimed to answer this question.

METHODS
The authors reviewed data from patients with a previously untreated single brain metastasis, who were treated with resection at The University of Texas M.D. Anderson Cancer Center (1993–2012). Data related to the patient, tumor, and methods of resection were obtained. Discharge Karnofsky Performance Scale (KPS) scores and 30-day postoperative complications were noted. Complications were considered major when they persisted for longer than 30 days, resulted in hospitalization or prolongation of hospital stay, required aggressive treatment, and/or were life threatening.

RESULTS
During the study period, 1033 eligible patients were identified. The median age was 58 years, 83% had a KPS score greater than 70, and 81% were symptomatic at surgery. Sixty-two percent of the patients underwent en bloc resection of their tumor, and 38% underwent piecemeal resection. There were significant differences between the 2 groups in terms of preoperative tumor volume, tumor functional grade, and symptoms at presentation, among others. The overall complication rates were 13% for patients undergoing en bloc resection and 19% for patients undergoing piecemeal resection (p = 0.007). The incidences of major complications and neurological complications were also significantly different. There was a trend in the same direction for major neurological complications, although it was not significant. Among patients undergoing piecemeal resection of tumors in eloquent cortex, 24% had complications (13% had major, 18% had neurological, 9% had major neurological, and 13% had select neurological complications; 4% died within 1 month of surgery). Among those undergoing en bloc resection of such tumors, 11% had complications (6% had major, 8% had neurological, 4% had major neurological, and 4% had select neurological; 2% died within 1 month of surgery). The differences in overall, major, neurological, and select neurological complications were statistically significant, but 1-month mortality and major neurological complications were not. In addition, within subcategories of tumor volume, the incidence of various complications was generally higher for patients undergoing piecemeal resection than for those undergoing en bloc resection.

CONCLUSIONS
The authors' results indicate that postoperative complication rates are not increased by en bloc resection, including for lesions in eloquent brain regions or for large tumors. This gives credence to the idea that en bloc resection of brain metastases, when feasible, is at least as safe as piecemeal resection.