The first 3 months after BCNU wafers implantation in high-grade glioma patients: clinical and radiological considerations on a clinical series

PURPOSE: Carmustine (1,3-bis[2-chloroetyl]-1-nitrosurea (BCNU)) wafers are approved for the local treatment of newly diagnosed and recurrent malignant glioma. Reassuring data on both safety and efficacy of treatment have been previously reported by phase III studies. Although most of related adverse events are reported in the first few months after surgery, there is a lack in the literature of radiological data regarding this period. Few anecdotal experiences have been reported about surgical bed cyst occurrence. The aim of our study is to analyse the radiological course of patients treated with wafers implantation focusing on the relationship between radiological data, and in particular bed cyst occurrence, and safety data. METHODS: Forty-three patients affected by malignant glioma underwent surgical removal and BCNU wafers implantation at the Department of Neurosurgery of Padova from April 2007 to October 2009. Safety data were collected according to previously reported phase III studies. Patients underwent clinical and radiological evaluation (MRI) postoperatively, then before discharge, at 1 month, then every 2 months. In the study were included only patients whose both 1- and 3-month MRIs were available. Finally, 36 out of 43 patients were available for the revision. FINDINGS: Fifty-eight percent of patients treated with BCNU wafers presented a bed cyst of the surgical cave at the 1-month MRI. Forty-eight percent of them were symptomatic. Conversely, among patients who presented one or more adverse event (27%), bed cyst was detected in up to 90% of cases (OR 7.35), being intracranial hypertension more frequently associated (OR 7.35; p value <0.05). In general, cysts presented a benign behaviour in the sense that patients promptly improved with corticosteroid treatment, never required surgery, never reported permanent neurological deficits. CONCLUSIONS: Surgical bed cyst occurrence in BCNU wafer-treated patients resulted more frequent than expected. Familiarity with the event is important to correctly handle a possible evolving phenomenon. However, only further larger experiences and prospective studies could reveal how the understanding of such event might be helpful to improve safety data.