Utility of CT-cisternogram for radiosurgery in trigeminal neuralgia: A not-to-be forgotten technique.

Radiosurgery (RS) is a well-established ablative therapy for trigeminal neuralgia (TGN). Successful RS requires the delivery of an extremely high dose of radiation to a small cisternal portion of the nerve, which lies amidst critical structures. This study describes the utility of CT-cisternogram in RS targeting for TGN. We report on patients with TGN who required CT-cisternogram for target identification for CyberKnife (CK) RS at our institution between September 2010 and April 2015. CT-cisternogram is a well-tolerated procedure that adds useful information to RS planning. Illustrative cases with complex anatomy and MRI artifacts related to postoperative changes and Teflon implant are described. CT-cisternogram is a complementary imaging modality that is useful in some patients, for RS target delineation.