Kidney Tumor Ablation: A Nonsurgical Alternative to Nephrectomy

Radiofrequency ablation (RFA) and microwave ablation (MWA) of kidney tumors, or kidney tumor ablation, is an effective alternative to surgical resection for small renal tumors that have not spread beyond the kidney. It is a minimally invasive, nonsurgical procedure with a recovery time of less than 24 hours. 

UCSF is a pioneering site for the imaging and diagnosis of kidney tumors, and the UCSF team of interventional radiologists includes some of the nation’s foremost experts in this image-guided procedure.


  • Cure rate is equivalent to surgery for tumors that are smaller than 4 cm
  • Can be performed as an outpatient procedure
  • Patient can usually resume normal activities within 24 hours 


Primarily for malignant renal tumors that are less than 4 cm

Optimal Candidates

Ideal candidates are patients who have a small (< 4 cm) Stage I renal cell carcinoma with no evidence of spread beyond the kidney and: 

  1. cannot undergo a partial nephrectomy, or
  2. are elderly, or
  3. have impaired kidney function, or
  4. are otherwise high-risk patients. 

Kidney Tumor Ablation FAQs

What is the procedure like?

While the patient is under anesthesia or conscious sedation, the interventional radiologist uses computed tomography (CT) to identify the tumor, which has already been identified from prior imaging. Biopsy of the mass, if not already completed, is done at the beginning of the ablation session. Then a thin needle-shaped probe is advanced through the patient’s skin until the tip of the probe is correctly placed inside the tumor. The radiologist then activates the probe—either with an electrical current of radiofrequency or microwave energy or with a cold gas—to create extreme heat or cold around the tip of the probe. The temperature destroys the tumor instantly. The procedure takes two to three hours including preparation time; the actual procedure usually takes an hour or less. The patient will experience some controllable pain for a few hours after the procedure, but the pain typically resolves rapidly with mild medication. The patient is sent home within 24 hours of the procedure and can resume normal activities. 

How do I prepare for the procedure?

Prior to the procedure, the patient meets the interventional radiologist at the Interventional Radiology Clinic to discuss the procedure and any questions that may arise.  The patient undergoes a history and physical exam, receives any needed lab tests, and signs a consent form. Patients meet with the anesthesia staff during the Clinic visit as well.

How do I follow-up for the procedure?

One of our physician’s assistants calls the patient after the patient is sent home to ensure there are no complications. A report is sent to the referring physician within 24 hours to indicate the results of the procedure and any recommended follow-up care.

How reputable are your physicians?

UCSF’s Interventional Radiology Section is world-renowned. We are supported by a team of top anesthesiologists, physician’s assistants, nurses and technologists who are all highly experienced in the kidney tumor ablation procedure.

How to Order Kidney Tumor Ablation for Your Patients

Consultations should include:

  1. Patient demographics;
  2. Patient insurance;
  3. Referral (Brief description of medical condition and reason for consultation;
  4. Mail a CD with images from the patient to: Ronald Zagoria, MD, 505 Parnassus Avenue, Room M-372, San Francisco, CA 94143. 

After reviewing the images, one of our physicians will contact the referring physician to discuss the consult and next steps.

Please send direct consult requests via email to [email protected].

Billing & Insurance

After a kidney tumor ablation procedure is scheduled, UCSF’s Central Authorization Unit will help patients and referring practices with pre- service insurance authorization or pre-service coverage determination when the patient is referred by a UCSF provider. Patients referred by non-UCSF providers must obtain insurance authorization through their referring physician’s office. In most cases this procedure is covered by insurance plans, including Medicare. UCSF’s Radiology Billing Department is happy to answer any questions about billing or provide price estimates for any Radiology services, call 415-514-8888.

Our Radiologists

Have any questions about kidney tumor ablation? We want to hear from you. Please contact us:

Associate Professor
Assoc Prof Clinical Radiology
Division Chief, Body Interventional Radiology
Professor Clinical Radiology
Associate Professor
Director of Quality, Interventional Radiology
Assoc Prof Clinical Radiology