Interventional magnetic resonance image-guided percutaneous cryoablation of renal tumors. (Case Report).

Abstract: We describe the first two cases of percutaneous cryoablation under magnetic resonance imaging guidance. To date, this minimally invasive procedure has been used for the treatment of renal cell tumors in patients who cannot tolerate or refuse surgical nephrectomy. The two patients described showed no evidence of recurrence or complications 35 and 36 months after the procedure.

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Discussion

Cryoablation of renal tumors via an open technique was first reported in 1996. (1) This was done intraoperatively with ultrasound guidance. Subsequent reports describe the laparoscopic views of renal cryoablation using ultrasound guidance. (2) Two cases of percutaneous renal cryoablation using ultrasound control have also been reported. (3) The two patients presented in this case report were the first of a larger clinical trial in which percutaneous renal cryoablation using MRI guidance was studied. (4) Compared with ultrasonography, the use of MRI to monitor cryoablation offers clear advantages in visualizing both the tumor mass and the black ice ball formation (Figs. 3-5). The ability of the MRI to produce complete, unobscured images in multiple planes in near real time increases the likelihood that no viable tumor will be left outside the margins of the ice ball and that nontargeted tissue is not injured. In summary, two cases of percutaneous cryoablation of renal cell carcinoma under MRI control are repor ted. There is no evidence of tumor recurrence or other serious complications at 35 and 36 months, respectively, after cryoablation.

Accepted March 6, 2002.

References

(1.) Delworth MG, Pisters LL, Fornage BD, von Eschenbach AC. Cryotherapy for renal cell carcinoma and angiomyolipoma. J Urol 1996;155:252-255.

(2.) Gill IS, Novick AC, Soble JJ, Sung GT, Remer EM, Hale J, et al. Laparoseopic renal crycablation: Initial clinical series. Urology 1992;52:543-551.

(3.) Uchida M, Imaide Y, Sugimoto K, Uehara H, Watanabe H. Percutaneous cryosurgery for renal tumors. Br J Urol 1995;75:132-137.

(4.) Shingleton WB, Sewell PE Jr. Percutaneous renal tumor cryoablation with magnetic resonance imaging guidance. J Urol 2001;165:773-776.

RELATED ARTICLE: Key Points

* Image-guided cryoablation is a feasible technique in patients with renal tumors.

* Cryoablation lends itself well to magnetic resonance imaging.

* Some patients with renal cell carcinoma are excellent candidates for renal cryoablation.

Case Reports

Patient 1

A 50-year-old black man presented with a history of chronic renal failure, insulin-dependent diabetes mellitus, congestive heart failure, hypertension, pancreatitis, and alcohol abuse. In April 1999, he was found to have a 1.5-cm mass in the left kidney (Fig. 1). The creatinine level at that time was 1.6 mg/dl.

An Institutional Review Board-approved protocol has been established for cryoablation of a renal cell carcinoma in the interventional magnetic resonance imaging-guided cryoablation procedure followed by nephrectomy. The patient was enrolled in this protocol. On April 23, 1999, the patient was positioned prone for interventional magnetic resonance imaging (MRI) (IMRI system, Sigma SP; General Electric, Milwaukee, WI) and was given general anesthesia. A 3-mm diameter cryoprobe (CryoHit; Galil Ltd., Tel Aviv, Israel) was positioned in the renal mass using sagittal, coronal, and axial MRI guidance (Figs. 2-4).

The mass was frozen to -180[degrees]C using the cryoprobe pressurized argon gas system. Using the IMRI system to visualize the black ice ball as well as the tumor mass, the ice ball was increased in size until it exceeded the margins of the tumor in all planes by 5 mm (Figs. 2-4). Three freeze/thaw cycles were done over the entire treatment area. The procedure took approximately 100 minutes. The patient tolerated the procedure well and was discharged from the hospital a few days later, after stabilization of his other medical problems. Subsequently, the patient refused nephrectomy. Because of multiple medical disorders, it was concluded that this was a reasonable decision. Computed tomography (CT) with intravenous contrast medium approximately 1 year after cryoablation showed dramatic shrinkage of the renal mass and no evidence of enhancement (Fig. 5). There was mild progression of chronic renal failure during the first year after cryoablation. The creatinine value in July 2000 was 2.4 mg/dl, but renal functi on is adequate, with a creatinine value of 1.6 mg/dl in June 2001. At his last follow-up visit at 25 months after cryoablation, no evidence of tumor recurrence was found (Fig. 6). He later died as a result of unrelated causes.

Patient 2

A 77-year-old white male retired surgeon had adenocarcinoma of the colon diagnosed in November 1996.

In early 1997, he had a right hemicolectomy. In his preoperative workup, he was found to have a renal cell carcinoma in the left kidney. After biopsy, a left nephrectomy was done in January 1998. He was subsequently found to have a second renal cell carcinoma in the right kidney, for which a right heminephrectomy was done in November 1998. In June 1998, a third renal cell carcinoma was found involving the remaining portion of the right kidney. At that time, he was advised that renal sparing surgery was not feasible. 1-le declined the removal of his remaining kidney and dialysis. Follow-up CT was done in December 1998 and showed the mass had increased slightly in size (Fig. 7).

In January 1999, he came to the University of Mississippi Medical Center; after extensive discussion, it was decided that he was a candidate for percutaneous cryoablation under MRI guidance. His pretreatment creatinine level was 2.2 mg/dl. On May 17, 1999, the patient was positioned prone in the IMRI system and treated as in Case 1. The procedure took approximately 106 minutes. The patient tolerated the procedure well and was discharged home the next morning. He denied any pain and reported only mild flank discomfort on stretching or bending. He was given permission to play golf 1 day after his discharge.

Follow-up CT scans at 1 week, 1 month, 3 months, 6 months, and 1 year revealed no enhancement of the mass and showed progressive shrinkage of the tumor, with the margins becoming irregular (Figs. 8-11). The creatinine value was 1.8 mg/dl 1 week after the procedure and has remained constant to date. The patient continues to lead a normal life and plays golf several times a week. He has experienced no complications or untoward side effects from this procedure. At approximately 47 months after cryoablation, MRI revealed progressive shrinkage of the mass and no evidence of tumor recurrence (Fig. 12). As expected, this patient has also declined surgical nephrectomy.

From the Department of Radiology and the Division of Urology, University of Mississippi Medical Center, Jackson, MS.

Reprint requests to Jeffrey C. Howard, MD, Department of Radiology, University of Mississippi Medical Center, 2500 N. State Street, Jackson, MS 39216. Email: [e-mail]

Copyright [C] 2003 by The Southern Medical Association

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