J Neurol Surg B Skull Base 2012; 73 - A426
DOI: 10.1055/s-0032-1314337

Influence of Modern Low-Dose Multislice Spiral Computed Tomography on Target Registration Errors in Image-Guided Skull Base Surgery

G. Widmann 1(presenter), M. Fasser 1, P. Schullian 1, A. Zangerl 1, W. Puelacher 1, M. Rasse 1, H. Riechelmann 1, R. Bale 1, W. Jaschke 1
  • 1Innsbruck, Austria

Objective: The objective of the study was to evaluate whether low-dose protocols influence the target registration error (TRE) in multislice spiral computed tomography (MSCT)-guided skull base surgery.

Design: Anthropomorphic phantom study.

Materials and Methods: An optical navigation system was used to evaluate TRE in a skull phantom using three modern MSCTs (Sensation open 40-slice intraoperative, Definition Flash 128-slice, and LightSpeed VCT 64-slice), as well as the following protocols: Identical baseline protocols (BP) at 120 kV/100 mAs, low-dose protocols in care dose/dose modulation (LD-I) 100 kV/35 ref. mAs, (LD-II) 80 kV/40–41ref. mAs, and (LD-III) 80 kV/15–17 ref. mAs. CTDIvol and DLP were obtained from the DICOM readout for all MSCT scanners and protocols.

Results: In all MSCT scanners, TRE did not significantly differ between the baseline and the lowest protocols: 1.36 versus 1.43 mm for the Sensation open, 1.31 versus 1.43 mm for the LightSpeed VCT, and 1.15 versus 1.14 mm for the Definition Flash. Compared with the reference CTDIvol of the German Government of 9 mGy, the lowest protocols allowed approximately a 3-fold dose reduction for the Sensation open, and a 12-fold dose reduction for the LightSpeed VCT and Definition Flash.

Conclusions: Modern MSCT scanners allow substantial dose reductions, which may not influence the accuracy in image-guided skull base surgery. Implementation of optimized protocols is encouraged to reduce radiation exposure.