Introduction: Spinal metastases are common, occurring in 30% of cancer patients (1-3). Instrumented spinal stabilization can preserve neurological function and reduce pain in select oncologic patients (4-6). Spinal neuronavigation improves screw placement accuracy (7,8); however its use in oncological operations remains relatively unstudied. Concern exists that utilizing spinal neuronavigation will prolong operative time (9,10).

Methods: Consecutive instrumented oncologic spinal operations were retrospectively reviewed. Patients were placed in two groups based on the method used for pedicle screw placement: 2-dimensional fluoroscopy versus spinal neuronavigation with 3-dimensional imaging. These groups were compared to examine age, number of pedicle screws placed, number of laminectomy levels, operative time, estimated blood loss, post-operative discharge day, and need for reoperation due to pedicle screw misplacement.

Results: There were 39 operations examined; 14 utilized 2D fluoroscopy and 25 utilized spinal neuronavigation. The mean ages of the patients were 64.71±7.21 and 63.24±6.95 (p = 0.534), mean number of pedicle screws placed was 8.07±1.98 and 7.84±1.34 (p = 0.667), mean number of laminectomy levels was 2.18±1.25 and 1.60±1.02 (p = 0.126) in the 2D fluoroscopy and spinal neuronavigation groups respectively. The mean operative time was 200.79±34.99 minutes compared with 193.48±43.77 minutes (p = 0.596), estimated blood loss was 790.00±769.61 ml and 389.80±551.43 ml (p = 0.068), and the mean number of days the patients were hospitalized following the operation prior to discharge was 7.64±4.63 and 6.40±3.23 (p = 0.331) in the 2D fluoroscopy and spinal neuronavigation groups respectively.

Conclusions: There was no significant difference in length of operative time when spinal neuronavigation was utilized as compared with standard 2D fluoroscopy for instrumented oncologic spinal surgery. There was a trend towards a significant decrease in estimated blood loss in the spinal neuronavigation cases. Concern over operative time should not be a barrier to using spinal neuronavigation in oncologic cases of spinal instability requiring instrumentation.

Patient Care: Implementing spinal neuronavigation for oncology patients may improve operative safety without increasing operative time.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Compare the expected length of OR time for instrumented oncologic spine surgery with 2-dimensional fluoroscopy versus spinal neuronavigation, 2) Describe the potential benefits of spinal neuronavigation in instrumented oncologic spine surgery.

References: 1. DiSibio G, French SW. Metastatic patterns of cancers: results from a large autopsy study. Arch Pathol Lab Med. 2008 Jun;132(6):931-9. 2. Ortiz Gómez JA. The incidence of vertebral body metastases. Int Orthop. 1995;19(5):309-11. 3. Wong DA, Fornasier VL, MacNab I. Spinal metastases: the obvious, the occult, and the impostors. Spine (Phila Pa 1976). 1990 Jan;15(1):1-4. 4. Patchell RA, Tibbs PA, Regine WF, Payne R, Saris S, Kryscio RJ, Mohiuddin M, Young B. Direct decompressive surgical resection in the treatment of spinal cord compression caused by metastatic cancer: a randomised trial. Lancet. 2005 Aug 20-26;366(9486):643-8. 5. Kim JM, Losina E, Bono CM, Schoenfeld AJ, Collins JE, Katz JN, Harris MB. Clinical outcome of metastatic spinal cord compression treated with surgical excision ± radiation versus radiation therapy alone: a systematic review of the literature. Spine (Phila Pa 1976). 2012;37(1):10.1097/BRS.0b013e318223b9b6. 6. Akeyson EW, McCutcheon IE. Single-state posterior vertebrectomy and replacement combined with posterior instrumentation for spinal metastasis. J Neurosurg. 1996 Aug;85(2):211-20. 7. Allam Y, Silbermann J, Riese F, Greiner-Perth R. Computer tomography assessment of pedicle screw placement in thoracic spine: comparison between free hand and a generic 3D-based navigation techniques. Eur Spine J. 2013 Mar;22(3):648-53. 8. Mason A, Paulsen R, Babuska JM, Rajpal S, Burneikiene S, Nelson EL, Villavicencio AT. The accuracy of pedicle screw placement using intraoperative image guidance systems. J Neurosurg Spine. 2014 Feb;20(2):196-203. 9. Härtl R, Lam KS, Wang J, Korge A, Kandziora F, Audigé L. Worldwide survey on the use of navigation in spine surgery. World Neurosurg. 2013 Jan;79(1):162-72. 10. Barsa P, Frölich R, Šercl M, Buchvald P, Suchomel P. The intraoperative portable CT scanner-based spinal navigation: a viable option for instrumentation in the region of cervico-thoracic junction. Eur Spine J. 2016 Jun;25(6):1643-50.