title: Percutaneous cryoablation of small kidney tumours under magnetic resonance imaging guidance: medium-term follow-up.
abstract: OBJECTIVE
  Minimally invasive treatment of small kidney tumours remains a challenge. Cryoablation has recently been advocated for such neoplasias. However, few series evaluating this therapeutic regimen are as yet available. The goal of this retrospective study was to evaluate the initial clinical experience of magnetic resonance imaging (MRI)-guided percutaneous cryotherapy of small renal tumours.
  
  
  METHODS
  Seven patients with small renal tumours [mean diameter 21 (11-30) mm] underwent percutaneous renal tumour cryoablation using the Cryo-Hit delivery system. The procedure was performed in an MRI interventional unit, using a 0.23 Tesla open MRI imaging system. Five men and two women were included in the group. The average age was 61.5 (34-84) years. The patients had a solitary kidney (n = 2), renal insufficiency (n = 4) or a kidney graft (n = 1). The intervention was performed under general anaesthesia. Average time for the whole procedure was 235 min with 26 min of effective treatment time. Mean follow-up was 28 (7-43) months.
  
  
  RESULTS
  All tumours were successfully ablated. There were no perioperative complications. Mean hospital stay was 2.4 (2-5) days. One patient stayed for 5 days because therapeutic anticoagulation had to be reinitiated. No significant change in the perioperative value of the serum creatinine was noticed. No radiographic evidence of disease recurrence or new tumour development was identified during the follow-up.
  
  
  CONCLUSIONS
  In this small group of patients, percutaneous renal tumour cryoablation under MRI guidance was efficient and carried no morbidity. Hospital stay was remarkably shorter than that of surgically treated patients. At medium-term follow-up, no recurrence has been identified, but long-term follow-up is required.
authors.affiliation: Division of Urologic Surgery, Department of Surgery, Geneva University Hospital, Geneva, Switzerland. alessandro.caviezel@hcuge.ch
authors.forename: Alessandro
authors.initials: A
authors.lastname: Caviezel
authors.forename: Sylvain
authors.initials: S
authors.lastname: Terraz
authors.forename: Franz
authors.initials: F
authors.lastname: Schmidlin
authors.forename: Christoph
authors.initials: C
authors.lastname: Becker
authors.forename: Christophe E
authors.initials: CE
authors.lastname: Iselin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018207:Angiomyolipoma / Q000473:pathology / Q000601:surgery*; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000601:surgery*; D003404:Creatinine / Q000097:blood; D003452:Cryosurgery / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery*; D007902:Length of Stay; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D009367:Neoplasm Staging; D011183:Postoperative Complications / Q000097:blood*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D047368:Tumor Burden
chemical_list: D003404:Creatinine