title: Ablation of colorectal liver metastases by irreversible electroporation: results of the COLDFIRE-I ablate-and-resect study.
abstract: OBJECTIVE
  Irreversible electroporation (IRE) is a new ablation technique that relies on high-voltage electrical pulses. This clinical study evaluates the pathological response of colorectal liver metastases (CRLM) treated with IRE and the clinical safety and feasibility.
  
  
  METHODS
  Ten patients with resectable CRLM were included. During laparotomy, the metastases were treated with IRE and resected 60 min later. Safety and feasibility were assessed based on adverse events, laboratory values, technical success and intra-operative ultrasound findings. Tissue response was assessed using triphenyl tetrazolium chloride (TTC) vitality staining and (immuno)histochemical stainings (HE, complement-3d and caspase-3).
  
  
  RESULTS
  Ten lesions with a mean diameter of 2.4 cm were successfully electroporated and resected, on average, 84 min later (range 51-153 min). One minor transient cardiac arrhythmia occurred during IRE. Ultrasound showed a sharply demarcated hypoechoic ablation zone around the tumour. TTC showed avitality of all lesions, covering the complete tumour in 8/10 lesions. Although immunohistochemistry proved heterogeneous and difficult to interpret within the tumours, it confirmed irreversible cell damage in the tumour-free margin of all specimens.
  
  
  CONCLUSIONS
  This ablate-and-resect study demonstrated avitality caused by IRE of CRLM in humans. Further characterisation of tissue- and tumour-specific electrical properties is warranted to improve ablation protocols for maximised tissue ablation.
  
  
  CONCLUSIONS
  • Irreversible electroporation induces cell death in colorectal liver metastases within 1 h. • The ablation zone shows a sharp demarcation between avital and vital tissue. • Apoptosis is involved in cell death of colorectal liver metastases after IRE. • Effects of IRE can be monitored real-time using intraoperative ultrasound. • Local electrical heterogeneities of tumour tissue may require tumour-specific ablation protocols.
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Centre, de Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands, hj.scheffer@vumc.nl.
authors.forename: H J
authors.initials: HJ
authors.lastname: Scheffer
authors.forename: K
authors.initials: K
authors.lastname: Nielsen
authors.forename: A A J M
authors.initials: AA
authors.lastname: van Tilborg
authors.forename: J M
authors.initials: JM
authors.lastname: Vieveen
authors.forename: R A
authors.initials: RA
authors.lastname: Bouwman
authors.forename: G
authors.initials: G
authors.lastname: Kazemier
authors.forename: H W M
authors.initials: HW
authors.lastname: Niessen
authors.forename: S
authors.initials: S
authors.lastname: Meijer
authors.forename: C
authors.initials: C
authors.lastname: van Kuijk
authors.forename: M P
authors.initials: MP
authors.lastname: van den Tol
authors.forename: M R
authors.initials: MR
authors.lastname: Meijerink
mesh_terms: D055011:Ablation Techniques / Q000379:methods*; D000368:Aged; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery*; D018274:Electroporation / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D007813:Laparotomy; D008113:Liver Neoplasms / Q000175:diagnosis / Q000556:secondary* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D049268:Positron-Emission Tomography; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed