Daily low-dose carboplatin as a radiation sensitizer for newly diagnosed malignant glioma

Surgical resection followed by local field radiotherapy is currently our mo st effective approach to treatment for most patients with malignant glioma. Carboplatin chemotherapy has direct cytotoxic effects on glioma cells and acts as a radiation sensitizer to enhance cell killing. Its demonstrated ef ficacy as a sensitizer in other solid tumors led to this clinical trial of carboplatin as a radiation sensitizer in the treatment of newly diagnosed g lioblastoma multiforme (GBM) and anaplastic astrocytoma (AA). Fourteen pati ents (nine GBM and five AA) were treated with daily low-dose carboplatin 25 mg/m(2) intravenously within 2 h of their fractionated radiotherapy to a t otal dose of 600 mg/m(2). No significant toxicities attributable to this co mbined therapy were observed. All patients have progressed, with median tim e to progression of 16 weeks. Eleven patients have died, with median surviv al of 38 weeks for the entire cohort. Although this regimen appeared safe, there was no benefit in survival time compared to historical patients treat ed with radiotherapy. The limitations and future potential for the strategy of radiation sensitization are discussed.