Current Trends in Glioblastoma Treatment

Abstract

Glioblastoma (also called glioblastoma multiforme – GBM) is a primary brain neoplasm, representing about 55% of all gliomas. It is a very aggressive and infiltrative tumor. Glioblastoma is usually highly malignant, with more than 90% 5-year mortality and a median survival of about 14.6 months. Compared to other cancers, the survival rate has not greatly changed over time and no current treatment is curative for this disease. Because the tumor has a heterogeneous cell population containing several types of cells, the treatment for GBM is one of the most challenging in clinical oncology. This chapter will discuss the current approaches in glioblastoma treatment, including resection techniques, chemotherapy and radiation GBM, postoperative reactive changes and parenchymal damage as a result of surgery. Postoperative contrast-enhancing tumor mass is typically used to delineate residual GBM and completeness of removal. It is better to use volumetric analysis of the preopera tive and postoperative tumor to accurately measure EOR and residual volume (RV). Reactive postoperative changes can be seen as early as 18 hours on MRI, but usually does not appear in the first 3–4 days. The EOR was identified as a strong prognostic factor for survival in GBM, together with patient’s age and patient’s functional status. Surgical removal has a critical role in GBM management because the only potentially modifiable risk factor associated with survival is EOR. The gross-total resection is not always possible. Thus, several studies have been conducted to evaluate EOR threshold which may serve as minimum surgical goal to achieve. Other studies demonstrated that EOR is not an ideal indicator to the success of the surgery, because it is a percentage value, reported to initial volume of the tumor, which can vary widely. Contrast-enhancing RV is considered a more clinically relevant measure and a stronger predictor of survival than EOR, representing the tumor mass existing prior to starting medical therapy. Chaichana et al. in 2014 evaluated newly diagnosed GBM patients who