Study of Brain Tumors (Tectal Tumors) Using Magnetic Resonance Imaging

INTRODUCTION

Current State of Knowledge Tectal plate gliomas are relatively rare tumors of childhood with
a reported incidence of 10%. Their typical clinical presentation is symptoms and signs of
hydrocephalus and are often incidentally diagnosed in the imaging work-up of children with
hydrocephalus.

Tectal tumors in children comprise a subcategory of brainstem tumors with unique clinical,
imaging, and spectroscopic features. There is debate whether they truly represent brainstem
tumors or whether they are a site of benign cellular overgrowth. The majority of these
tumors are pathologically benign and show no or minimal growth. Not all tectal plate
tumors, however, have this typically benign course. Some can manifest a more aggressive
behavior. There have been reports in the past attempting to analyze the histology and
behavior of these tumors. None of the prior series looking at these tumors have included
Magnetic Resonance Spectroscopy (MRS) analysis.

Study Justification It is interesting that according to where tumors occur in the brainstem
usually indicates what their histology and behavior is. Although not absolute, we know that
tumors can have a very poor prognosis versus an extremely good prognosis depending on their
location in the brainstem. Yet there are always the cases that do not act in the typical
fashion and this is where MRS can prove helpful.

We noticed that, in the first few cases of tectal plate tumors where an MRS evaluation was
performed, that a reproducible spectroscopic pattern was seen. It is important to have
obtained a metabolic signature of the tumor at the time of the initial study. This way we
can follow the metabolic stability of the tumor and be in the position to document any
interval change which could prospectively indicate a potentially more aggressive behavior.
This should prompt a closer than normal interval follow-up. This is especially important in
the follow-up of tectal plate lesions since they are usually stable lesions that show no
growth and the follow-up studies could be a year apart at least. Closer follow-ups could be
scheduled in tumors showing metabolic signs indicating a potential for more aggressive
behavior.

Study Goal Our goal for this study is to evaluate tectal plate tumor MRI/MRS findings in
comparison with the patients’ clinical progress and therapy to determine correlation. If we
can prospectively identify which tumors have the potential to act more aggressively, we can
tailor our management accordingly.

PROCEDURES AND METHODS

Study Phases This study will consist of two phases. The first phase will consist of
prospective MRS scans of normal control subjects as normal controls and the second phase
will consist of retrospective chart reviews of MRI/MRS and clinical follow up records on
patients with tectal plate glioma diagnosis.

STUDY PHASE I Study Population For phase I, the subject population will consist of 10-12
healthy volunteers age 4 to 18 who are already scheduled for a brain MRI for reasons other
than tectal plate glioma evaluation. These subjects will be recruited from the Scottish
Rite campus and will be subjects who do not require sedation for the MRI.

Subject Consent Potential subjects for Phase I will be identified by the Principal
Investigator upon arrival of their previously scheduled MRI. The potential subjects will
sign a standard consent form from Children’s Healthcare of Atlanta for their previously
scheduled MRI examination itself and for any contrast that may be needed for the
examination. In those consent forms, the subjects will be informed of all possible risks
and complications associated with the MRI examination itself and any contrast to be given
(if necessary) as part of their routine care. The research MRS study will be discussed with
the potential subjects and an additional research consent form will be presented to them for
review. The subjects will have ample time to review the consent form, be given the
opportunity to have their questions answered, and be advised that participation is voluntary
and refusal to participate in the study will be without prejudice. Consent for the MRS
study will be obtained in writing by the PI prior to the scans.

Study Procedures Following consent of these subjects in this study, the subjects will have
their routine MRI, followed by the extra 10 to 15 minutes in the scanner for the MRS scan of
their tectal plate.

Risks The additional time in the scanner in order to complete the MRS scan may cause
discomfort. The subjects will be monitored throughout the MRI/MRS duration by the study
staff for determination of any Adverse Events or other indications that the study may need
to be stopped.

Because information which will be collected in this study identifies the subjects, there is
the risk of unintentional disclosure if this information. Certain steps will be followed in
this study to help protect the subjects’ privacy and confidentiality. Only the PI and
authorized research staff will have access to database. No data will be identifiable to
study subjects - each subject will be assigned a unique study identifier when entered into a
database. No identifying features will be published or presented.

Benefits Taking part in this research study may not benefit the normal control subjects
personally, but we may learn new things that will help others.

Study Costs There is no cost to the subjects for the MRS study. The subjects will be given
$50 at the end of the MRS study to compensate them for their time and effort in helping out
with research.

STUDY PHASE II

Subject Population Once the normal control MRS data is obtained from Phase I, this data will
be used to support the second phase of the study. Phase II will involve retrospective chart
reviews of MRI/MRS and clinical follow up records on patients with tectal plate glioma
diagnosis from 2000-2004. An estimated 30-40 charts are expected to be reviewed for the
retrospective portion of this study.

Study Procedures The MRS peaks will be visually analyzed by the PI with ratios calculated.
The percent deviation of the peaks in the tectal glioma patients from the normal controls
will be calculated. Statistical analysis will then be performed to determine significance.

Risks Because information which will be collected in this study identifies the subjects,
there is the risk of unintentional disclosure if this information. Certain steps will be
followed in this study to help protect the subjects’ privacy and confidentiality. Only the
PI and authorized research staff will have access to database. No data will be identifiable
to study subjects - each subject will be assigned a unique study identifier when entered
into a database. No identifying features will be published or presented.

Inclusion Criteria:

- patients who are already scheduled for a brain MRI at Children's Healthcare of
Atlanta at Scottish Rite for reasons other than tectal plate glioma evaluation

Exclusion Criteria:

- patients with tectal plate glioma