First-line treatment of malignant glioma with carmustine implants followed by concomitant radiochemotherapy: a multicenter experience

Neurosurg Rev (2010) 33:441–449. DOI 10.1007/s10143-010-0280-7

Randomized phase III trials have shown significant improvement of survival 1, 2, and 3 years after implantation of 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) wafers for patients with newly diagnosed malignant glioma. But these studies and subsequent non-phase III studies have also shown risks associated with local chemotherapy within the central nervous system. The introduction of concomitant radiochemotherapy with temozolomide (TMZ) has later demonstrated a survival benefit in a phase III trial and has become the current treatment standard for newly diagnosed malignant glioma patients. Lately, this has resulted in clinical protocols combining local chemotherapy with BCNU wafers and concomitant radiochemotherapy with TMZ although this may carry the risk of increased toxicity.

We have compiled the treatment experience of seven neurosurgical centers using implantation of carmustine wafers at primary surgery followed by 6 weeks of radiation therapy (59–60 Gy) and 75 mg/m2/day TMZ in patients with newly diagnosed glioblastoma followed by TMZ monochemotherapy. We have retrospectively analyzed the postoperative clinical course, occurrence and severity of adverse events, progression-free interval, and overall survival in 44 patients with newly diagnosed glioblastoma multiforme. All patients received multimodal treatment including tumor resection, BCNU wafer implantation, and concomitant radiochemotherapy. Of 44 patients (mean age 59±10.8 years) with glioblastoma who received Gliadel wafer at primary surgery, 28 patients (64%) had died, 16 patients (36%) were alive, and 15 patients showed no evidence of clinical or radiographic progression after a median follow-up of 15.6 months. At time of analysis of adverse events in this patient population, the median overall survival was 12.7 months and median progression-free survival was 7.0 months. Surgical, neurological, and medical adverse events were analyzed. Twenty-three patients (52%) experienced adverse events of any kind including complications that did not require treatment. Nineteen patients (43%) experienced grade 3 or grade 4 adverse events. Surgical complications included cerebral edema, healing abnormalities, cerebral spinal fluid leakage, meningitis, intracranial abscess, and hydrocephalus. Neurological adverse events included newly diagnosed seizures, alteration of mental status, and new neurological deficits. Medical complications were thromboembolic events (thrombosis, pulmonary embolism) and hematotoxicity.

Combination of both treatment strategies, local chemotherapy with BCNU wafer and concomitant radiochemotherapy, appears attractive in aggressive multimodal treatment schedules and may utilize the sensitizing effect of TMZ and carmustine on MGMT and AGT on their respective drug resistance genes. Our data demonstrate that combination of local chemotherapy and concomitant radiochemotherapy carries a significant risk of toxicity that currently appears underestimated. Adverse events observed in this study appear similar to complication rates published in the phase III trials for BCNU wafer implantation followed by radiation therapy alone, but further add the toxicity of concomitant radiochemotherapy with systemic TMZ. Save use of a combined approach will require specific prevention strategies for multimodal treatments.

Combination of Intracranial Temozolomide With Intracranial Carmustine Improves Survival When Compared With Either Treatment Alone in a Rodent Glioma Model

Neurosurgery:March 2010 – Volume 66 – Issue 3 – p 530–537.doi: 10.1227/01.NEU.0000365263.14725.39

BACKGROUND: Local delivery of temozolomide (TMZ) through polymers is superior to oral administration in a rodent glioma model.

OBJECTIVE: We hypothesized that the observed clinical synergy of orally administered TMZ and carmustine (BCNU) wafers would translate into even greater effectiveness with the local delivery of BCNU and TMZ and the addition of radiotherapy in animal models of malignant glioma.

METHODS: TMZ and BCNU were incorporated into biodegradable polymers that were implanted in F344 rats bearing established intracranial tumors. We used 2 different rodent glioma models: the 9L gliosarcoma and the F98 glioma.

RESULTS: In the 9L rodent glioma model, groups treated with the combination of local TMZ, local BCNU, and radiation therapy (XRT) had 75% long-term survivors (defined as animals alive 120 days after tumor implantation), which was superior to the combination of local TMZ and local BCNU (median survival, 95 days; long-term survival, 25%) and the combination of oral TMZ, local BCNU, and XRT (median survival, 62 days; long-term survival, 12.5%). To simulate the effect of this treatment in chemoresistant gliomas, a second rodent model was used with the F98 glioma, a cell line relatively resistant to alkylating agents. F98 glioma cells express high levels of alkyltransferase, an enzyme that deactivates alkylating agents and is the major mechanism of resistance of gliomas. The triple therapy showed a significant improvement in survival when compared with controls (P = .0004), BCNU (P = .0043), oral TMZ (P = .0026), local TMZ (P = .0105), and the combinations of either BCNU and XRT (P = .0378) or oral TMZ and BCNU (P = .0154).

CONCLUSION: The survival of tumor-bearing animals in the 9L and F98 glioma models was improved with the local delivery of BCNU and TMZ combined with XRT when compared with either treatment alone or oral TMZ, local BCNU, and XRT.