J Urol. 2002 Aug;168(2):660; discussion 660-1.
Percutaneous renal tumor cryoablation with magnetic
resonance imaging guidance.
Shingleton WB, Sewell PE Jr.
Division of Urology and Department of Radiology,
University of Mississippi Medical Center, Jackson, Mississippi,
PURPOSE: Cryoablation of small renal tumors has
been performed mainly via the laparoscopic or open approach. This
study was done to assess the feasibility and safety of performing
percutaneous renal tumor cryoablation using interventional magnetic
resonance imaging (MRI) for monitoring. MATERIALS AND METHODS: Patients
with radiography documented small renal tumors 4 cm or less in diameter
were offered percutaneous renal tumor cryoablation performed in
an interventional MRI unit. Patients received general anesthesia
or intravenous sedation and were placed into the interventional
MRI unit. Under MRI guidance a 2 or 3 mm cryoprobe was advanced
into the renal mass and the mass was subjected to 3 freeze-thaw
cycles at -80 to 70C. Patients were hospitalized overnight for observation.
Followup imaging with MRI or computerized tomography and physical
examinations were done at 1 week, and 1, 3, 6 and 12 months. RESULTS:
Ten men and 10 women 49 to 76 years old (mean age 58) with a total
of 22 tumors have been treated, including 1 with bilateral lesions
and another with 2 tumors in 1 kidney. Mean tumor diameter was 3
cm. (range 1.8 to 7.0). Two patients with a mass exceeding study
entry criteria (5 and 7 cm, respectively) who were not open surgery
candidates were treated on a compassionate basis. Average treatment
time was 97 minutes (range 56 to 172). To date 1 patient has had
evidence of persistent tumor on followup imaging and required re-treatment.
The only complication was a superficial wound abscess. Mean followup
was 9.1 months (range 3 to 14) with no radiographic evidence of
disease recurrence or new tumor development. CONCLUSIONS: In this
small series of patients percutaneous renal tumor cryoablation was
technically feasible with minimal morbidity. At limited followup
there appears to be no radiological evidence of new tumor development.
Percutaneous cryoablation may prove to be an additional treatment
option for small renal tumors.