Abstracts

Functional neuroimaging can address challenges of epilepsy localization, and sometimes preclude the need for intracranial electrodes. Ictal SPECT has developed into a useful tool in the presurgical evaluation of patients with medically-intractable localization-related epilepsy. The purpose of the study was to evaluate the performance of ictal injections in an epilepsy unit that may reduce the injection latency time., In our epilepsy-unit, nursing-staff inject doses of ^99mTc-HMPAO at bedside, during or at seizure onset. The unit has 8 beds with a nursing station facing them, all in a single large room. Nursing staff follows a pre-establish protocol. Patients are designated prior or during admission to obtain an ictal SPECT. All patients have at least two seizures recorded prior to obtaining an ictal SPECT to characterize events. If the patient does not have a seizure on the first day of the attempt, the dose then is used for an interictal scan, in that way the tracer is not wasted, and the ictal scan is tried the following day. Brain SPECT is performed later on a gamma camera equipped with high resolution collimators. We analyzed the time to actual injection of tracer from seizure onset. Percentage of wasted vials and contamination rate are evaluated as well., Since the implementation of the new protocol in february of 2005, fifty-four scans have been performed: twenty three ictal and 35 interictal. Latency of ictal injection was found to be between 5 and 40 seconds (mean 19.7 sec, SD 10.3), 21.7% of radiopharmaceutical vials were wasted, contamination rate was nil., Latency of injections and percentage of vials wasted indicated a very efficient protocol in compared to what has been published in the literature. Our results show that latency time of injection can be decreased, in an epilepsy unit, with adequately trained personnel and pre-established protocols., (Supported by GE Healthcare Medical Diagnostics (Grant-In-Kind).)