Hippocampal Radiation Exposure and Memory

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00603694
Recruitment Status : Completed
First Posted : January 29, 2008
Last Update Posted : June 23, 2016
Information provided by (Responsible Party):
University Health Network, Toronto

January 16, 2008
January 29, 2008
June 23, 2016
September 2007
December 2013   (Final data collection date for primary outcome measure)
Not Provided
Not Provided
Complete list of historical versions of study NCT00603694 on Archive Site
Not Provided
Not Provided
Not Provided
Not Provided
Hippocampal Radiation Exposure and Memory
Hippocampal Radiation Exposure and Memory: A Pilot Study

Neurocognitive impairment as a result of gamma knife radiosurgery has not been well studied and is poorly understood. Radiosurgery to the base of skull for the treatment of benign and malignant disorders may consequently impair memory function. There is a need to evaluate changes in memory function that may be associated with such exposures.

In this pilot study, we will investigate changes in hippocampal-dependent memory function in 10 patients receiving a low SRS dose to the hippocampus. We will also investigate such changes in a no-dose control group and a high-dose control group. This study will provide preliminary estimates of variance in memory changes associated with radiation exposure, and will then permit us to design future studies with the appropriate sample size justification.

Not Provided
Observational Model: Case Control
Time Perspective: Prospective
Not Provided
Not Provided
Probability Sample
Patients who have consented to GK radiosurgery or cranial radiation.
  • Arteriovenous Malformation
  • Schwannoma
  • Trigeminal Neuralgia
Not Provided
  • 1
    (Experimental group): Receiving > 2 Gy SRS to left hippocampus (n=10)
  • 2
    (Low-dose control group): Receiving < 0.5 Gy SRS to left hippocampus (n=10)
  • 3
    (High-dose control group): Receiving whole brain PCI (n=10)
Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
December 2013
December 2013   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • Patients planned for radiosurgery for benign disorders (Groups 1&2).
  • Patients planned for prophylactic cranial irradiation (Group 3)

Exclusion Criteria:

  • Previous cranial radiation
  • Severe psychiatric disorder
  • Severe cognitive or memory impairment (MMSE < 21)
  • Non-English speaking, which will potentially make memory testing difficult and unreliable.
  • Other medical conditions deemed by the PI or associates to make the patient ineligible for protocol procedures
  • Patients on steroid medications.
  • Left hand dominant patients
  • Dose exposure to left hippocampus >0.5Gy and <2Gy. We will attempt to estimate dose to hippocampus prior to enrollment using pre-planning on diagnostic imaging to minimize exclusion of patients due to dose exposure >0.5 Gy and < 2Gy following baseline memory testing.
  • Benzodiazepine or narcotics given on the day of radiotherapy/radiosurgery prior to completion of the study procedures
  • Previous brain surgery within one year prior to radiosurgery
  • Pregnant women
Sexes Eligible for Study: All
18 Years and older   (Adult, Older Adult)
Contact information is only displayed when the study is recruiting subjects
Not Provided
Not Provided
University Health Network, Toronto
University Health Network, Toronto
Not Provided
Not Provided
University Health Network, Toronto
June 2016