Trial Information

Electromagnetic Tracking of Devices During Interventional Procedures - A Cryoablation Study

The objective of this study is to assess and quantify any differences between assisted
(using real-time visualization of tracked cryo-probes) and unassisted cryoablation
procedures using pre-procedure CT scans or CT fluoroscopy. To assess this, physicians will
perform ablation procedures with and without the Percu Nav device. Data will be collected on
the angle of needle entry unassisted and then assisted by PercuNAv to determine if the added
imaging information modifies the physician's needle approach.

Each patient will have a pre-procedure CT image set of the area of interest acquired. The
patient will be scanned in the same position that the ablation will be performed in,
although not requisite. Sterile registration patches will be applied to the patient's skin
around the area of interest prior to the scan, ensuring that suitable windows are left
available for needle entry. The patient will undergo these pre-procedural scans as part of
the usual clinical evaluation of the lesion to undergo ablation. The scans may be acquired
with or without contrast, at the discretion of the physician.

Control group: The physician will perform the procedure using the standard of care method
(CT only), without the additional information being recorded by the PercuNav device. The
tracking device will be placed on the patient's skin at the desired point of entry. Without
displaying the PercuNav screen to the physician, a screen capture will be taken to record
the approach path. At the point of insertion, the time stamp will be recorded and the start
button will be pressed. Once the physician states they are at the defined target a screen
capture will be taken on the PercuNav and the distance to target and time stamp will be
recorded by pushing the start button again. At the end of the procedure a verification CT
scan will be taken with the needle in place and sent to the PercuNav.

Percu Nav group: The physician will perform the procedure using the standard of care
procedure with the additional information displayed and recorded by the PercuNav device (CT
and PercuNav). The tracking device will be placed on the patient's skin at the desired point
of entry. Without displaying the PercuNav screen to the physician, a screen capture will be
taken to record the approach path. The physician will be shown the PercuNav screen and will
correct the desired approach path and another screen capture will be taken. At the point of
insertion, the time stamp will be recorded and the start button will be pressed. Once the
physician states they are at the defined target a screen capture will be taken on the
PercuNav and the distance to target and time stamp will be recorded. At the end of the
procedure a verification CT scan will be taken (as is part of the regular standard of care
procedure) with the needle in place and sent to the PercuNav.

The outcome measures that will be evaluated in the groups include:

1. Accuracy - The distance between the "virtual" needle position (tracking data) and the
actual needle position (CT confirmation scan)), where applicable (TRE)

2. Time to reach a clinically acceptable target in the tumor

3. The total procedure time

4. Accuracy of needle targeting - The vector of each needle insertion (The initial vector
allows us to project the path to the pre-defined target. If the initial entry point is
not ideal, the path to the target will need adjustment)