The value of gamma probe in the detection of epileptogenic focus

Radiol Bras. 2014 Jan/Fev;47(1):IX Even though epilepsy is known since the antiquity and, despite the great developments in the diagnosis and clinical treatment of this disease, there are still cases of refractory epilepsy to conventional antiepileptic drugs. In such cases of refractory epilepsy when an epileptogenic focus has been defined, surgery may be indicated for focus resection, if it is not located in an eloquent area. Imaging methods are routinely utilized to detect lesions that may be the cause for refractory epilepsy. In such patients, the identification of an epileptogenic focus represents a decisive factor for the indication or not of a surgery for management of the seizure. The association of structural imaging methods, such as magnetic resonance imaging, with functional methods such as SPECT (ictal and interictal) and PET plays a significant role in the identification of such lesions, allowing that many cases previously diagnosed as cryptogenic epilepsy have the disease origin defined and surgery indicated. Additionally, electroencephalography and video-encephalography data are essential to confirm the presence of abnormal electrical activity coinciding with the focal lesions identified at the imaging studies. The utilization of nuclear medicine with a gamma probe (portable gamma ray detector) is known as radioguided surgery. Such procedure modality already has its use recognized in oncology, and has changed the approach to several types of malignant neoplasms (breast, melanoma, colorectal cancer), neuroendocrine neoplasms and parathyroid surgery. The gamma probe allows the real-time obtention of essential information for the surgeon regarding the disease location and its extent besides information about margin resection.