The course of intracranial pressure and volume-pressure relationships following extirpation of meningiomas and astrocytomas

Safety profile of carmustine wafers in malignant glioma: a review of controlled trials and a decade of clinical experience

BACKGROUND

Carmustine (1,3-bis [2-chloroethyl]-1-nitrosourea, or BCNU) wafers are approved for recurrent glioblastoma and newly diagnosed malignant glioma (MG). Based on considerable clinical experience and use in multimodal regimens, the safety of BCNU wafers needs a re-evaluation.

SCOPE

A review of literature from 1996 to February 2008 was conducted on the safety of BCNU wafer in MG patients using search criteria in Medline, EMBASE, and BIOSIS. Abstracts from relevant US and European meetings were also evaluated. Three Phase III (two were pivotal) and 26 non-Phase III studies met inclusion criteria. Overall incidence was estimated for each adverse event (AE), and data from individual studies were summarised as median (range) rates. Comparisons were based on consistent similarities or differences across overall incidence, median rate and range.

FINDINGS

BCNU wafer group AE rates from the two pivotal Phase III trials ranged from 4-23% for cerebral oedema, 4-9% for intracranial hypertension, 14-16% for healing abnormalities, 5% for CSF leaks, 4-5% for intracranial infection, 19-33% for seizures, 10% for deep vein thrombosis, and 8% for pulmonary embolus. There were no notable differences in AE rates between the two pivotal Phase III and 26 non-Phase III studies. For the non-pivotal studies, the overall incidence of AEs was low, ranging from 0.2% for intracranial hypertension to 9.6% for healing abnormalities. Healing abnormalities, intracranial infection, and seizures were the most consistently reported AEs, having been observed in 16, 12, and 11 studies, respectively. Rates of healing abnormalities appeared higher in recurrent than in newly diagnosed disease. There were no notable differences between BCNU wafer plus adjuvant treatment (e.g., temozolomide) and BCNU wafer alone, with the exception of haematologic toxicity.

CONCLUSION

This review of safety data for BCNU wafers provides reassurance that the AE rates reported in current treatment strategies including multimodal treatment approaches are comparable to those observed in the initial registration studies. The broad range of AE rates may reflect differences in the perioperative and postoperative management. Clinical experience suggests that strategies may exist to reduce the risk of complications.

Surgical impact on brain tumor invasion: a physical perspective

It is conventional strategy to treat highly malignant brain tumors initially with cytoreductive surgery followed by adjuvant radio- and chemotherapy. However, in spite of all such efforts, the patients' prognosis remains dismal since residual glioma cells continue to infiltrate adjacent parenchyma and the tumors almost always recur. On the basis of a simple biomechanical conjecture that we have introduced previously, we argue here that by affecting the 'volume-pressure' relationship and minimizing surface tension of the remaining tumor cells, gross total resection may have an inductive effect on the invasiveness of the tumor cells left behind. Potential implications for treatment strategies are discussed.

Prognostic factors for lower respiratory tract infections after brain-tumor surgery

Nosocomial infection of the lower respiratory tract is a frequent and serious complication after major operations. A 32% incidence of lower respiratory tract infections was found after brain-tumor surgery in 289 patients, with a 21% incidence of pneumonia. In 186 of these patients (Group A), five factors were identified which were associated with an increased risk of postoperative lower respiratory tract infection. These were: age, tumor type, cardiac insufficiency, preoperative disturbances of consciousness, and preoperative corticosteroid treatment. Based on these factors, a risk score was developed which correlated well with the incidence of infection in this group of patients. In a second group of patients (Group B), the derived risk score was applied and was found to possess a high degree of validity. As long as patients were intubated postoperatively, their freedom from infection decreased exponentially, with a half-life of 3.5 days.

Course of intracranial pressure after extirpation of posterior fossa tumours

Forty-seven patients with posterior fossa tumours underwent continuous monitoring of intracranial pressure (ICP) in the early postoperative period by means of an intraventricular catheter. ICP values were very low on the day of operation and subsequently became normal in 37 patients. ICP values were raised in 10 patients. The relationship between the ICP and the clinical course was investigated. Patients were subdivided according to the clinical postoperative course into three groups: good, temporarily deteriorated, poor clinical course. The two first groups showed lower values in the ICP than he third one, nevertheless the relationship between the ICP and the postoperative clinical course is marked but not strict. Our data may have some clinical relevance for the treatment of hydrocephalus before extirpation of posterior fossa tumours.