title: Percutaneous computed tomography-guided cryoablation for renal tumor: Experience in 30 cases.
abstract: BACKGROUND
  Percutaneous cryoablation is a minimally invasive alternative for surgical resection of a renal tumor. We report our experience with applying computed tomography-guided cryoablation in renal tumors, focusing on the technique, safety, and treatment response.
  
  
  METHODS
  We retrospectively reviewed the medical records of patients who received cryoablation from October 2009 to August 2013 for renal tumor diagnosed by imaging studies performed at Taipei Veterans General Hospital, Taipei, Taiwan. Patient comorbidities and tumor morphology, technical success rate, tumor control rate, renal function change, and complications were recorded.
  
  
  RESULTS
  A total of 30 patients (32 tumors) were treated, comprising 30 renal cell carcinomas and two angiomyolipomas. The mean age of the patients was 73.7 years (range, 34-89 years). The patients were referred for percutaneous cryoablation arising from old age, medical comorbidities, or preexisting malignancy. The mean follow-up period was 15.2 months (range, from 32 days to 47.4 months). According to the Clavien-Dindo classification, surgical complications included one Grade III, four Grade II, and two Grade I complications. The mean decrease in hemoglobin was 0.77 g/dL (range, from +1.1 g/dL to -3 g/dL). The mean hospital stay after cryoablation was 2.2 days (range, 1-10 days). Incomplete ablation was noted in two patients and local tumor recurrence in two patients. One of them received repeated cryoablation and achieved successful local control. Of the 22 renal cell carcinoma patients with follow-up period > 6 months, 19 patients achieved successful local tumor control (86.4%). The percentage change of glomerular filtration rate before and 3-6 months after the procedure was +1.9%, which was statistically nonsignificant (p = 0.94).
  
  
  CONCLUSIONS
  Computed tomography-guided percutaneous cryoablation is a safe and effective technique for treating renal tumors with excellent renal function preservation.
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Wei-Jen
authors.initials: WJ
authors.lastname: Lai
authors.affiliation: National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC; Division of Urology, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Hsiao-Jen
authors.initials: HJ
authors.lastname: Chung
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Chun-Ku
authors.initials: CK
authors.lastname: Chen
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC. Electronic address: shshen@vghtpe.gov.tw.
authors.forename: Shu-Huei
authors.initials: SH
authors.lastname: Shen
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Hsiao-Ping
authors.initials: HP
authors.lastname: Chou
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Yi-You
authors.initials: YY
authors.lastname: Chiou
authors.affiliation: National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC; Department of Radiology, Cheng-Hsin General Hospital, Taipei, Taiwan, ROC.
authors.forename: Jia-Hwia
authors.initials: JH
authors.lastname: Wang
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Cheng-Yen
authors.initials: CY
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003452:Cryosurgery / Q000009:adverse effects; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed
keywords: cryoablation; imaging-guided ablation; renal cell carcinoma