Clinical Update: Treatment of Glioblastoma Multiforme with Radiolabeled Antibodies that Target Tumor Necrosis

Glioblastoma multiforme (GBM) is one of the most intractable cancers in humans, and yet, in the past decade, incremental advances in the treatment of brain tumors have begun to suggest that effective therapies may be on the horizon. Here we review the latest treatments available to patients and focus on a promising radiotherapeutic strategy that employs the isotope 131Iodine conjugated to an antibody that binds the necrotic core found in all solid tumors. Historically, GBM patients who relapse have a median survival time of no more than 24 weeks; however, the Tumor Necrosis Therapy discussed here has already provided a good quality of life for several patients years beyond the historical median survival time. The cases of two long-term survivors are reviewed, and data are presented to show that initial post-treatment assessments of tumor progression actually turned out to be tumor necrosis and inflammation. Given the current lack of imaging modalities that can distinguish between tumor progression and pseudoprogression, these cases further highlight the challenges faced by physicians in differentiating disease progression or recurrence from necrosis.