MR Perfusion Methods in Patients With Suspected Recurrent High Grade Gliomas

Radiation therapy is an important adjunct in the treatment of patients with glioma, although a common side effect is radiation-induced injury of brain parenchyma. Unfortunately, conventional MRI is not accurate in differentiating radiation-induced brain injury from recurrent tumour, both of which may demonstrate progressive contrast enhancement. Recent studies have suggested that perfusion MRI could improve this differentiation. Perfusion MRI can be performed with an injection of exogenous contrast using dynamic contrast enhancement (DCE) or dynamic susceptibility contrast enhancement (DSC). Perfusion MRI can also be performed without contrast injection using arterial spin labeling (ASL) or intravoxel incoherent motion (IVIM). DCE-MRI relies on accurate measurement of T1 values in order to convert the MRI signal intensity to contrast concentration. Dynamic susceptibility-weighted contrast enhancement (DSC) perfusion is the most common technique used in clinical practice but measurement of tumor relative cerebral blood volume (rCBV) can be biased by extravascular contrast leakage and susceptibility-weighted artifacts. The purpose of this study is to evaluate the accuracy of perfusion MR imaging using non-contrast and contrast-based techniques in differentiating recurrent tumour from radiation-induced brain injury in patients with known high grade glioma. The investigators will compare the accuracy of IVIM, ASL, DCE and DSC techniques. A secondary goal of the study is to compare two new different T1 mapping methods used for DCE-MRI.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

Patients enrolled must have:

1. Had a diagnosis of high grade glioma and had received chemoradiation
2. Developed a new lesion or an increase size of their treated lesion on follow-up MRI (either on post contrast T1W images or on FLAIR)
3. Karnofsky performance status (kps) score \>70 (potential candidate for reresection of stereotactic radiation)

Exclusion Criteria:

1. Patients under 18 years of age
2. Pregnant patients (for women of child bearing potential - a negative serum beta HCGT is required).
3. Known or suspected allergies to gadolinium-based contrast agents.
4. Patients with chronic or acute renal insufficiency (glomerular filtration rate \< 30 mL/min/1.73m2), including acute renal insufficiency of any severity due to hepatorenal syndrome or in the perioperative liver transplantation period.
5. General contraindications to MRI such as pacemaker or ferromagnetic implants.
6. Severe cardiovascular disease
7. Intractable seizures while on adequate anticonvulsant therapy (more than one seizure per month for the past 2 months)
8. Sickle-cell anaemia or other known hemoglobinopathies, or other forms of haemolytic anaemia