Radio Frequency Ablation is a radiological procedure where a heat probe is inserted through the skin and into the tumor. Then the tip of the probe is heated, and “cooks” the tumor.

Cryotherapy is similar, except that the probe is a freezing device. Once the probe is in the tumor, the tip of the probe is cooled to form an ice ball, freezing the tumor to kill the cells.

In both cases, the heat or cold energy must kill cells around the tumor in order to insure that all the tumor cells will be killed. Both procedures are attractive in that they are not open surgery, and the recovery is generally very quick. However, they are nevertheless both surgical procedures with risks of their own.

New treatments and new machines are being developed all the time that may further improve kidney treatment. The goal is to kill or remove only the tumor cells, and leave all the working nephrons doing the work of the kidney. A new DaVinci machine, for example, allows the surgeon to drive a robotic machine that can do very precise laparoscopic surgeries. As with all these options, the experience of the physician operating the machine and the treatment plan are critically important.

instrument entering tumor electrodes deployed within tumor

Radiofrequency is a type of electrical energy used to create heat. During a radiofrequency procedure, an ablation probe is placed directly into the target tissue. The generator is turned on and the target temperatures are input. The radiofrequency energy flows through the electrodes, causing ionic agitation, and therefore friction, in the nearby tissue. The friction creates heat, and once sufficient temperatures have been reached, the heat kills the target tissue within a few minutes. Source: University of Southern California Liver Transplant program.

Picture of a cryoprobe designed to be used under MR guidance

A cryoprobe about 8 inches long, designed to be used under MR guidance, before (top) and after (bottom) creation of an ice ball. It took 10 minutes to create this 1 inch ice ball in water in the lab. Source: Silverman et al., Renal Tumors: MR Imaging-guided Percutaneous Cryotherapy, Radiology, 2005;236:716-724

We have prepared the following list of Questions to Ask Your Doctor, in order to help you have a complete conversation before the procedure.

Considering Radio Frequency Ablation or Cryotherapy for Kidney Tumors?

Questions to Ask Your Doctor

1. Is the size of this tumor appropriate for this treatment -- or is it too big? How does size effect success rates?

2. How difficult will it be to get to the tumor?

3. Are there any structures adjacent to the tumor that might accidentally be injured by the treatment? (blood vessels, urine collection system, nerves or bowel)

4. Is there a way to protect those structures and still ensure complete destruction of the tumor? (e.g., injection of fluid or gas)

5. Are there other considerations that might recommend against using this therapy on this tumor?

6. Who might I see for a second opinion on other minimally invasive or image guided treatment options?

7. What do you feel are the chances of killing all the tumor cells in this tumor? or will some be left behind to grow back?

8. How long does it take to realize that a tumor was not completely treated?

9. How much normal kidney will be destroyed by the treatment?

10. How is the treatment likely to affect my kidney function?

As printed in the VHL Family Forum 16:1, January/February 2008. For permission to reprint, please contact VHL Family Alliance, editor@vhl.org.