Five overlapping ablation zones of a CRLM recurrence

A 82-year old patient with past history of colon cancer had developed a metachronous CRLM that had been treated with MWA using US guidance in 2021. In 2023 the patient presented with a large crescent-shaped local recurrence (55mm) in segment VIII. Due to the possibility of planning and executing large overlapping ablation zones, a CAS-One IR MWA was chosen over a hemi-hepatectomy and radiation therapy, with curative intent. A total of six ablation zones (the 6th on a separate tumor) were planned and executed using the Medtronic Emprint system. Segmentation of the vasculature and surrounding organs helped plan trajectories and ablation zones to minimize risk. The 6-week post-intervention MRI highlights the success of this treatment.

Planning scan with vasculature segmented (red: segmentation of the tumorous region, orange: 5 mm safety margin, green: overlapping ablation zones) 

Planning scan with 3D reconstruction of estimated ablation zones and organ segmentation (green: overlapping ablation zones) 

6-week post-procedure MRI in axial and coronal view showcasing no local recurrence 

Name: Dr. Arash Najafi

Institution: Kantonspital Winterthur, Switzerland 

Patient sex:  Female 

Initial condition:

• 82-year old patient with post-operative colon cancer with a metastasis discovered in 2021
• A CRLM appeared and was ablated at the time with ultrasound guidance
• A crescent-shaped recurrence was discovered in March 2023 around the edges of the previous ablation zone

• Original metastasis was 55mm, recurrence was 28mm

Treatment: 

• MWA was chosen over a hemi-hepatectomy and radiotherapy, with curative intent, as the patient did not have further tumor progression  
• Five overlapping ablation zones using Medtronic Emprint were planned and simulated with the advantage of vascular structure segmentation in the new CAS-One IR software
• A sixth ablation zone was planned for another CRLM in segment VIII
• Anesthesia time was minimal due to careful planning of the six ablation zones

Result:

• Complete ablation, including clinical margins were observed after treatment
• No complication observed due to the ablation
• 6-week post intervention MRI showed clinical margins and no local recurrence for this large ablative area 
• The patient will remain under routine control
  
  
• CAS-One IR 4.1 enabled this complex treatment with its ability to systematically plan the treatment with accurate needle placement