The low grade glioma (LGG) is a type of brain tumor which is generally more common in younger age group patients. Most patients with LGG undergo surgery which is mostly incomplete due to concern about loss of function. This is an incurable disease. More than half of these patients progress to a higher grade with a worse outcome within five years of their diagnosis and only one-third survive for up to ten years. Post-operative radiation treatment improves local control without survival advantage. Efforts are being made without great success to select the patients with a higher risk of progression based on physical characteristics and histological features.

Tumor vascularity is thought to be the key element in tumor progression. Tremendous progress has been made in functional imaging by using magnetic resonance imaging (MRI) 3-Tesla (3T) and in biotechnology which can be used to investigate angiogenic gene profiles in order to identify gene signature for these tumors. In this study the investigators are proposing that patients of LGG with a higher risk of tumor progression may be selected by functional imaging and angiogenic profiles. These higher risk patients may be candidates for post-operative radiation in the future with a potential survival benefit.

Summary: Comprehensive analysis of the angiogenesis-related gene expression profiles and tumor perfusion of patients with LGG will provide a novel understanding of subgroup (low and high-risk) of LGG. Thus, this study will allow identifying clinically relevant factors predictive for tumor progression and to select patients in high-risk group for adjuvant radiation therapy.

Inclusion Criteria:

• Greater than 18 years of age
• Brain tumor with no contrast enhancement on conventional MRI and confirmed histological of LGG
• No adjustment treatment
• Consent to participate in study
• No contra-indication for dynamic contrast-enhanced (DCE)-MRI

patients referred to Cross Cancer Institute between 2004 and 2005