Purpose : To evaluate the current beliefs about the ways to reduce TRE value in image guided Sinus surgeries by rearranging the fiducial configuration, and investigating the best configurations for various surgical fields in a phantom study.
Methods : A new CT-compatible skull phantom consisting of implanted targets was designed to enable direct measurement of TRE in four fields of sinus surgery, i.e. Frontal, Ehtmoid, Sphenoid and Maxillary. The effects of different landmark configurations on TRE values, measured by Parsiss-IV navigation system were investigated to find the best landmark arrangement for each region, and compared to the TRE prediction formula to assess the clinically accepted landmark selection approaches based on this formula.
Results : It was shown that smaller values of TRE could be attained by bringing the center of fiducials to be more focused on the surgery target, and addition of more fiducials and keeping non-linear arrangement of landmark would not necessarily decrease the TRE value. Conclusion: Optimizing the landmark configuration is important for increasing the localization accuracy in image guided sinus surgeries. The common beliefs accepted in the clinical community about the ways to reduce the TRE are very general and should be adapted to specific field of image guided surgery.