Interventional Magnetic Resonance
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.
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.
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Coronal gadolinium enhanced T1-weighted MRI showing tumor in superior pole of left kidney.
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 (Figure 2, Figure 3, Figure 4).
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Coronal gradient MRI showing black ice ball formation consuming the renal tumor in superior pole of left kidney.
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Sagittal gradient MRI showing cryoprobe from posterior approach with tip entering renal tumor.
(Enlarge Image)
Axial gradient MRI showing cryoprobe from posterior approach with ice ball formation consuming tumor.
The mass was frozen to -180°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 (Figure 2, Figure 3, Figure 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 function 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.
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One year follow-up contrast enhanced axial CT demonstrating dramatic shrinkage of the renal tumor and no abnormal enhancement.
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25 month follow-up contrast enhanced axial CT demonstrating complete tumor ablation and minimal residual scar.
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. He 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).
(Enlarge Image)
Contrast enhanced axial CT showing enhancing exophytic mass in the remaining portion of the right kidney.
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 (Figure 8, Figure 9, Figure 10, Figure 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.
(Enlarge Image)
Follow-up contrast enhanced axial CT 1 week post-cryoablation of the right renal tumor.
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Follow-up contrast enhanced axial CT 1 month postcryoablation of the right renal tumor.
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Follow-up contrast enhanced axial CT 3 months postcryoablation of the right renal tumor.
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Follow-up contrast enhanced axial CT 6 months postcryoablation of the right renal tumor.
(Enlarge Image)
Gadolinium enhanced coronal MRI 47 months postcryoablation demonstrating small residual scar without evidence of tumor recurrence.
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.
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.
(Enlarge Image)
Coronal gadolinium enhanced T1-weighted MRI showing tumor in superior pole of left kidney.
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 (Figure 2, Figure 3, Figure 4).
(Enlarge Image)
Coronal gradient MRI showing black ice ball formation consuming the renal tumor in superior pole of left kidney.
(Enlarge Image)
Sagittal gradient MRI showing cryoprobe from posterior approach with tip entering renal tumor.
(Enlarge Image)
Axial gradient MRI showing cryoprobe from posterior approach with ice ball formation consuming tumor.
The mass was frozen to -180°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 (Figure 2, Figure 3, Figure 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 function 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.
(Enlarge Image)
One year follow-up contrast enhanced axial CT demonstrating dramatic shrinkage of the renal tumor and no abnormal enhancement.
(Enlarge Image)
25 month follow-up contrast enhanced axial CT demonstrating complete tumor ablation and minimal residual scar.
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. He 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).
(Enlarge Image)
Contrast enhanced axial CT showing enhancing exophytic mass in the remaining portion of the right kidney.
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 (Figure 8, Figure 9, Figure 10, Figure 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.
(Enlarge Image)
Follow-up contrast enhanced axial CT 1 week post-cryoablation of the right renal tumor.
(Enlarge Image)
Follow-up contrast enhanced axial CT 1 month postcryoablation of the right renal tumor.
(Enlarge Image)
Follow-up contrast enhanced axial CT 3 months postcryoablation of the right renal tumor.
(Enlarge Image)
Follow-up contrast enhanced axial CT 6 months postcryoablation of the right renal tumor.
(Enlarge Image)
Gadolinium enhanced coronal MRI 47 months postcryoablation demonstrating small residual scar without evidence of tumor recurrence.
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