Pilot study investigating the relationship between neurocognitive function, radiotherapy and cerebral white matter microstructure in low grade glioma patients by using MRI diffusion tensor imaging

Low grade gliomas occur in relatively young patients (between the ages of
30-50 years), have a good performance score, neurological function and
neurocognitive function when diagnosed. Patients with grade II or III glioma
and favorable prognostic features have a 10 year survival rate exceeding 50%.
Standard treatment consists of surgical debulking followed by postoperative
radiotherapy and chemotherapy.
Most patients develop cognitive dysfunction, which may greatly impact quality
of life for the patient but also for the next of kin. It is reasonable to
assume that cranial irradiation has a negative impact on neurocognitive
functioning. This may become apparent only after 5-10 years.
Diffusion tensor imaging (DTI) is an MRI-technique that can provide insight
into the microstructural integrity of cerebral white matter. It is more
sensitive to the detection of subtle white matter changes than conventional T1-
and T2 weighted imaging. Several studies exist in which MRI DTI was used to
study the effects of radiotherapy on white matter. These indicate the existence
of a dose-effect relationship as well as the existence of a relationship
between neurocognitive dysfunction and microstructural damage as revealed by
MRI DTI. However, these studies had very limited patient numbers and report
conflicting results.

To determine the correlation between neurocognitive function and the incidence
of DTI abnormalities on MRI in irradiated glioma patients.

All patients that are in follow up receive an MRI-scan bi-annually. This scan
will be extended by 15 minutes to allow running the abovementioned DTI
sequence. Scans will be obtained on the 3 Tesla (Prisma) scanner. Measuring
neurocognitive function in patients is standard care and will be performed by
the treating neurologist or another health care provider. Afterwards, the
correlation between neurocognitive function and DTI abnormalities will be
investigated. Anatomical changes will be related to the irradiated volume.

Patients do not benefit from participation in this study. Standard diagnostic
and therapeutic procedures remain unchanges, regardless of any study outcomes.
Participants will not incur any additional costs if they participate. There
will be no financial re-imbursement. The extra burden for participating
patients is elongation of their next MRI examination by 15 minutes (55 instead
of 40).