Microsurgery and radiosurgery for brainstem cavernomas: effective and complementary treatment options.

OBJECTIVE: To evaluate treatment options for brainstem cavernous malformations (BSCMs) using the results from a center with long-standing experience in microsurgical resection and Gamma Knife radiosurgery (GKRS) treatment of BSCMs. METHODS: Study participants were 67 symptomatic patients with BSCMs who were treated either microsurgically (n = 29) or radiosurgically (n = 38). Patients were followed for a minimum of 2 years (median, 7.7 years). A recent follow-up was performed. RESULTS: Patients receiving surgical treatment had mainly large, superficially seated lesions and experienced preoperative hemorrhages more often and presented with higher preoperative modified Rankin Scale scores. Patients receiving GKRS harbored smaller, deep-seated lesions, reflecting a selection bias. In both treatment groups, patients presented with significantly better modified Rankin Scale scores at follow-up than before intervention. Overall annual preoperative hemorrhage rates were 3.2% in microsurgery patients and 2.3% in radiosurgery patients. In the preoperative observation period, the rehemorrhage rate was 25.1% for microsurgery patients and 7.2% for radiosurgery patients. Hemorrhage rate after GKRS decreased significantly to 0.6% after 2 years. The postoperative hemorrhage rate was 8.8% but only for microsurgery patients with residual lesions. Advancements in microsurgical techniques improved surgical outcomes, resulting in a high total excision rate in the modern era. CONCLUSIONS: In the treatment of BSCM, patient selection and timing of surgery are crucial. If applied in a multidisciplinary neurosurgical center, microsurgery and radiosurgery are complementary treatment options that both result in reduced bleeding rates and improvement of clinical outcome.

Prognostic relevance of p53 protein expression in glioblastoma.

TP53 plays a key role in cellular response to DNA-damaging agents, and mutation of this gene, which is associated with immunohistochemically detectable p53 protein accumulation, may influence response to chemo- and radiotherapy. We investigated immunohistochemically the influence of p53 protein accumulation in 114 consecutive cases of primary glioblastoma treated by surgery and adjuvant radio- and chemotherapy. In addition, we determined cellular proliferation index using the antibody MIB-1 and apoptotic index of tumor cells using the TUNEL-assay. Twenty-nine patients (25.4%) were considered as positive with regard to p53 protein expression (>50% p53 immunostained tumor cells). Patients with p53 positive glioblastomas were significantly younger (mean age 54.4+/-2 years) than those with p53 negative tumors (mean age 61.4+/-1.1 years) (p=0.002, Mann-Whitney test). While no significant difference in apoptotic index was found, we observed a significantly higher MIB-1 labeling index (LI) in patients with p53 positive tumors (median LI: 36.4%) compared to p53 negative ones (median LI: 23.8%) (p=0.005, Mann-Whitney test). p53 protein expression was associated with significantly longer survival in univariate analysis (p=0.0399, log-rank test). In multivariate analysis of overall survival (Cox regression) only postoperative Karnofsky performance status remained as independent prognostic factor. We conclude that glioblastoma patients with immunohistochemically detectable p53 protein expression, who received adjuvant radio- and chemotherapy, have a significantly better overall survival, possibly due to increased sensitivity to this adjuvant treatment.