Devoted to diagnostic and interventional spine imaging and therapeutics


Imaging-guided percutaneous fiducial seed placement in the thoracic spine for Cyberknife stereotactic radiosurgery 2008

Interventional Spine Carla Ramas, MD, Orlando Ortiz, MD, ASSR Member Alan Katz, MD, Non ASSR Member Jonathan Haas, MD, Non ASSR Member Man Hon, MD, Non ASSR Member Matt Witten, PhD, Non ASSR Member Scientific Paper Purpose We report our preliminary experience with fluoroscopy-guided placement of gold seed fiducials in the thoracic spine in 28 outpatients (and ongoing) for localization of thoracic tumors during Cyberknife stereotactic radiosurgery. Methods & Materials The fiducials are placed bilaterally into two non-contiguous, alternating vertebral bodies using coaxial technique, strict aseptic technique, local lidocaine anesthesia at the puncture sites, and intravenous sedation and analgesia. A posterior bilateral transpedicular approach is used with the patient in the prone position. A 10 gauge Kyphx bone needle (Kyphon Co., Sunnyvale, CA) is advanced into the posterior pedicle. A twist drill is then used to create a working channel with a trajectory that is directed towards the lateral aspect of the vertebral body. When indicated, a biopsy specimen can be obtained using a biopsy cannula that can be inserted through the bone needle cannula. A 20 cm length 17G needle which contains a 1.2 mm gold fiducial, is then advanced into the working channel. The gold seed is then deployed into the vertebra under direct fluoroscopic visualization. This procedure is repeated on the opposite side of the vertebra such that two fiducials are placed per vertebra. Confirmatory radiographs are obtained in the frontal, lateral, and both 45 degree oblique projections. The puncture sites are secured with steri-strip bandaids. The patient is then recovered for 1 hour and discharged home. Results The procedure was efficiently and safely performed in all 28 patients. Successful fiducial placement was observed. Furthermore, stable fiducial locations were confirmed at one week stereotactic localizing CT's of the thoracic spine. The procedure provided effective localization for subsequent radiosurgery using the Cyberknife. Conclusion Fluoroscopy guided gold seed fiducial placement can be performed effectively and without complication using coaxial technique. Furthermore, placement of fiducial markers in the thoracic spine has shown increased efficacy, feasibility, and accuracy of Cyberknife stereotactic radiosurgery in patients with thoracic tumors. [gallery]