Evaluation of the Efficacy of Two Guidance Techniques (Standard Injected CT vs Porto-scanner With Angio-CT) for Thermoablation Treatment of Colorectal Cancer Liver Metastases

Hepatic metastases of colorectal cancer (CRC) are partially necrotic tumors mainly vascularized by the hepatic artery. When resectable, these metastases must be removed with a safety margin of 1 mm. Resection margins greater than 1 cm are associated with better disease-free survival and no local recurrence. Thermoablation systems allow for ablation zones of approximately 4.5-5 cm in diameter. For tumors \<3 cm, subject to perfect targeting, it is possible to obtain ablation margins of 1 cm, which would greatly reduce the local recurrence rate. Accurate assessment of these tumor boundaries and characterization of these margins are paramount to ensure complete ablation.

Thermoablation for these small liver metastases (\<3cm) has shown equivalent efficacy to surgery in terms of recurrence and survival with fewer complications. Thermoablation treatment is indicated for patients with stable disease undergoing chemotherapy. This leads to liver remodeling and metastases become difficult to see on ultrasound and CT scans. The study authors hypothesize that the porto-scanner guidance technique with Angio-CT for thermoablation treatment of CRC liver metastases will allow a better exploration of these metastases by allowing a better identification of the margins and thus ensure a more accurate and complete treatment for patients.


Eligibility Criteria:
Inclusion Criteria:

* The patient must have given their free and informed consent and signed the consent form
* The patient must be a member or beneficiary of a health insurance plan
* Patients with CRC liver metastases (\< 3 lesions, \< 3 cm in diameter), proven on MRI and/or Positron Emission Tomography scan.
* Patient eligible for thermoablation requiring CT guidance (at least one metastasis not visible on ultrasound).
* Treatment by thermoablation validated in multidisciplinary meeting.
* Eastern Cooperative Oncology Group performance score 0-2.
* ASA score 1-3.
* Life expectancy of more than 3 months.
* Renal function allowing iodinated contrast injection (clearance \> 30 mL/min), normal liver function (bilirubin \< 35 µmol/L) and hemostasis assessment allowing percutaneous procedure (PT \> 50%, platelets \> 50 G/L, anticoagulant treatment to be stopped).
* Postmenopausal patient or patient with effective contraception (hormonal or mechanical)
* Pregnancy test (bHCG blood) negative in the month prior to inclusion for patients of childbearing age

  * Patients with a history of radical treatment (surgery, radiofrequency or stereotactic radiotherapy) for liver metastases more than 6 months old.
  * Patient presenting a recurrence at a distance from the treated lesion (more than 1 cm from the scar).

Exclusion Criteria:

* The subject is participating in a category 1 interventional study, or is in a period of exclusion determined by a previous study
* The subject refuses to sign the consent
* It is impossible to give the subject informed information
* The patient is under safeguard of justice or state guardianship
* Lesion not eligible for thermoablation (proximity of the liver hilum and the main bile duct).
* Uncorrectable abnormalities of liver or blood functions (coagulation).
* Severe allergy to contrast media.
* Contraindication to MRI (pacemaker, neuro-stimulator, cochlear implant, metallic heart valve, claustrophobia).
* Uncontrolled infection.
* Any physical, physiological or psychological condition incompatible with study participation or patient compliance.
* Pregnant, parturient or nursing patient.
* Contraindications mentioned in the Product Monographs of the following drugs:

  * FLUCIS: Hypersensitivity to the active substance (fludeoxyglucose (18F)) or to one of the excipients.
  * VISIPAQUE 320
  * Hypersensitivity to the active substance or to any of the excipients mentioned in section 6.1.
  * History of immediate major or delayed cutaneous reaction (see section 4.8) to the injection of iodinated contrast material (Visipaque),
  * Decompensated cardiac insufficiency with systemic injection (only concerns high osmolarity ionic products),
  * Overt thyreotoxicosis,
  * Hysterosalpingography in pregnancy

    * patient with a history of radical treatment for liver metastases (surgery, thermoablation, stereotactic radiotherapy) less than 6 months old.
    * patient with recurrence within 1 cm of the scar.