Five overlapping ablation zones of a CRLM recurrence

Five overlapping ablation zones of a CRLM recurrence


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


  • 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


  • 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 

Learn more about the stereotactic navigation system CAS-One IR.

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