Minimally invasive approaches, such as cementoplasty, radiofrequency ablation (RFA) or cryotherapy, have emerged for the treatment of painful bone tumors. These techniques are performed percutaneously using CT or C-arm.To do this with more confidence, clinicians need to plan and guide needle trajectories during interventional procedures.
Courtesy of Dr. F. Deschamps, IGR – Villejuif, France.
Patient History
A 50-year-old male patient had a history of epidermoid carcinoma of the esophagus with a hepatic evolution.
The patient was suffering from lumbar pain due to a lysis of the anterior part of the L3 vertebra. He was referred for a dual radiofrequency ablation and cementoplasty treatment in order to relieve pain and consolidate his vertebra.
The patient was placed in a prone position and under general anesthesia.
An Innova CT at 40°/s acquisition of the vertebral anatomy was performed. A dedicated protocol on the Advantage Workstation Volume Share 4 enabled planning of the trans-pedicular needle trajectory. It allowed the physician to prepare the path between the patient’ skin and the right anterolateral part of L3. (Fig. 1)
The defined trajectory was then imported by Innova TrackVision, which superimposes the virtual needle over the real-time fluoroscopy.
The automatically computed “bullseye view”, angulations were transferred to the gantry, so that the virtual needle trajectory could be seen as a point over the fluoroscopy. (Fig. 2) This view increases confidence that the needle is in the right position for skin entry and in the right direction for advancement.
When the vertebra was reached, the C-arm was rotated to the “progress view”, which shows the needle trajectory as a line, to help monitor the advancement of the needle. (Fig. 3)
Innova TrackVision: View (Fig. 2) and “Progress View” (Fig. 3)
The bone anatomy was overlaid on the fluoroscopy to help verify in real time the registration between the real-time 2D fluoroscopy and the 3D anatomy on which the needle trajectory was based. (Fig. 4)
In case the patient has moved, Innova TrackVision allows the user to compensate for the mis-registration.
Once the needle was positioned at the tip of the virtual needle, the C-Arm orientation was switched to another angulations to match the real needle position with the planned trajectory. (Figs. 5 and 6)
Overlay of the virtual needle and 3D bone anatomy
Innova TrackVision showing the correlation between the Real trocar placement and the virtual needle as defined prior the puncture
The puncture allowed the placement of a 15cm Radionics needle (Burlington, MA, US) with an active part of 2cm for 4 minute ablation phase. A final temperature of 64°C was reached. Then a Cook 11 G needle (Bloomington, IN, US) was placed for an injection of several mL of cement to fill the osteolysis area.
A second Innova CT at 40°/s acquisition was performed to help assess the cement distribution and its relationship with the vertebra.
The can use the Advantage Workstation VolumeShare was used to compare (Fig. 7) at the same time the vertebra before the treatment (left), with the trocar in place (middle) and after the cement injection (right).
Comparison of Innova CT Volumes on Advantage Workstation VolumeShare
Conclusion
With Innova TrackVision and its registration tools, we’re more confident that we’re advancing the needle along the right trajectory. Besides vertebroplasty, Innova TrackVision has the potential to be a big help in guiding any type of needle-based procedure – especially for help planning difficult needle trajectories, or for physicians with limited experience in these types of interventions.
The clinical case above is displayed only for educational purpose and for the benefit of healthcare student and professional
