Endoscopic ultrasound-guided fiducial markers and brachytherapy.

Endoscopic ultrasound (EUS)-guided needle placement of small radiopaque particles paves the way for EUS-guided fiducial markers and brachytherapy. Stereotactic body radiation therapy relies on image-guided radiation therapy (IGRT), permitting escalation of radiation dose to tumors while minimizing dose to normal tissues. Fiducial markers are radiopaque spheres, coils, or seeds that are implanted in or near tumors for IGRT. Brachytherapy is a therapeutic modality for various cancers. Both require precise and minimally-invasive seed placement, which EUS provides. This article reviews recent literature regarding the safety and efficacy of these procedures and discusses novel concepts, including EUS-guided celiac ganglia radiation neurolysis.